VolumeJunction1Phase

This is a flow junction that has a volume and can connect 2 or more FlowChannel1Phase components in any orientation.

Formulation

See Volume Junction for the theoretical formulation.

Form Losses

Complex multidimensional interactions inside the junction cannot be practically modeled mechanistically but are instead approximated using a form loss factor $var element = document.getElementById("moose-equation-bb497e6f-5625-4db5-affd-6772f58416c9");katex.render("K", element, {displayMode:false,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ , which gives rise to source terms on the momentum and energy equations:

(1)var element = document.getElementById("moose-equation-0759539f-19e5-49e2-9d4a-506a4b8f9652");katex.render("\\mathbf{S}^{\\text{momentum}} = - K (p_{0,1} - p_1) A_\\text{ref} \\frac{\\mathbf{u}_1}{\\|\\mathbf{u}_1\\|} \\eqc", element, {displayMode:true,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});

(2)var element = document.getElementById("moose-equation-970a3910-bd8e-4e36-81f3-df5a3385750d");katex.render("S^{\\text{energy}} = - K (p_{0,1} - p_1) A_\\text{ref} \\|\\mathbf{u}_1\\| \\eqc", element, {displayMode:true,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});

where

$var element = document.getElementById("moose-equation-cf4bcb3c-59dd-4e4f-8bb4-274ac1033be3");katex.render("p_{0,1}", element, {displayMode:false,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ is the stagnation pressure of the first flow channel (see Usage),
$var element = document.getElementById("moose-equation-587929b0-8c09-47c6-b117-7a11f65b2586");katex.render("p_1", element, {displayMode:false,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ is the static pressure of the first flow channel,
$var element = document.getElementById("moose-equation-9b80131c-57d7-4cdb-b153-ad6c30deff4a");katex.render("A_\\text{ref}", element, {displayMode:false,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ is the reference cross-sectional area, and
$var element = document.getElementById("moose-equation-cefbcbb0-078e-4fb9-9296-c8744e11a1cb");katex.render("\\mathbf{u}_1", element, {displayMode:false,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ is the velocity in the first connected flow channel.

Usage

The parameter "connections" specifies ends of flow channel components to connect.

A form loss coefficient $var element = document.getElementById("moose-equation-f56446e4-98d9-4ded-b865-0fe6c18936ca");katex.render("K", element, {displayMode:false,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ may be specified using the parameter "K". The parameter "A_ref" is the reference cross-sectional area $var element = document.getElementById("moose-equation-ae7e0a25-1f05-464b-954c-37db55347de2");katex.render("A_\\text{ref}", element, {displayMode:false,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ used in Eq. (1) and Eq. (2). If it is not provided, the cross-sectional area of the first connection in "connections" is used.

note:Connection order matters when using form loss

The order of connections in "connections" has an impact when using form loss, since some quantities in Eq. (1) and Eq. (2) are taken from the first connection.

Initial conditions are specified with the following parameters:

"initial_T": temperature
"initial_p": pressure
"initial_vel_x": x-velocity
"initial_vel_y": y-velocity
"initial_vel_z": z-velocity

The "apply_velocity_scaling" parameter specifies whether to apply the scaling of Hong and Kim (2011) to the normal component of the velocity of the junction state, as described in Volume Junction.

Input Parameters

connectionsJunction connections
C++ Type:std::vector<BoundaryName>
Unit:(no unit assumed)
Controllable:No
Description:Junction connections
positionSpatial position of the center of the junction [m]
C++ Type:libMesh::Point
Unit:(no unit assumed)
Controllable:No
Description:Spatial position of the center of the junction [m]
volumeVolume of the junction [m^3]
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Volume of the junction [m^3]

Required Parameters

A_refReference area [m^2]
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Reference area [m^2]
K0Form loss factor [-]
Default:0
C++ Type:double
Unit:(no unit assumed)
Controllable:Yes
Description:Form loss factor [-]
apply_velocity_scalingFalseSet to true to apply the scaling to the normal velocity. See documentation for more information.
Default:False
C++ Type:bool
Unit:(no unit assumed)
Controllable:No
Description:Set to true to apply the scaling to the normal velocity. See documentation for more information.
initial_TInitial temperature [K]
C++ Type:FunctionName
Unit:(no unit assumed)
Controllable:No
Description:Initial temperature [K]
initial_pInitial pressure [Pa]
C++ Type:FunctionName
Unit:(no unit assumed)
Controllable:No
Description:Initial pressure [Pa]
initial_vel_xInitial velocity in x-direction [m/s]
C++ Type:FunctionName
Unit:(no unit assumed)
Controllable:No
Description:Initial velocity in x-direction [m/s]
initial_vel_yInitial velocity in y-direction [m/s]
C++ Type:FunctionName
Unit:(no unit assumed)
Controllable:No
Description:Initial velocity in y-direction [m/s]
initial_vel_zInitial velocity in z-direction [m/s]
C++ Type:FunctionName
Unit:(no unit assumed)
Controllable:No
Description:Initial velocity in z-direction [m/s]
scaling_factor_rhoEV1Scaling factor for rho*E*V [-]
Default:1
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Scaling factor for rho*E*V [-]
scaling_factor_rhoV1Scaling factor for rho*V [-]
Default:1
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Scaling factor for rho*V [-]
scaling_factor_rhouV1Scaling factor for rho*u*V [-]
Default:1
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Scaling factor for rho*u*V [-]
scaling_factor_rhovV1Scaling factor for rho*v*V [-]
Default:1
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Scaling factor for rho*v*V [-]
scaling_factor_rhowV1Scaling factor for rho*w*V [-]
Default:1
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Scaling factor for rho*w*V [-]
use_scalar_variablesTrueTrue if the junction variables are scalar variables
Default:True
C++ Type:bool
Unit:(no unit assumed)
Controllable:No
Description:True if the junction variables are scalar variables

Optional Parameters

control_tagsAdds user-defined labels for accessing object parameters via control logic.
C++ Type:std::vector<std::string>
Unit:(no unit assumed)
Controllable:No
Description:Adds user-defined labels for accessing object parameters via control logic.
enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Unit:(no unit assumed)
Controllable:No
Description:Set the enabled status of the MooseObject.

Advanced Parameters

Input Files

(modules/thermal_hydraulics/test/tests/problems/three_pipe_shock/three_pipe_shock.i)
(modules/thermal_hydraulics/tutorials/single_phase_flow/06_custom_closures.i)
(modules/thermal_hydraulics/test/tests/components/volume_junction_1phase/phy.deadend.i)
(modules/thermal_hydraulics/test/tests/components/volume_junction_1phase/err.missing_ics.i)
(modules/thermal_hydraulics/tutorials/single_phase_flow/05_secondary_side.i)
(modules/thermal_hydraulics/test/tests/misc/adapt/multiple_blocks.i)
(modules/thermal_hydraulics/test/tests/problems/natural_circulation/volume_junction.i)
(modules/thermal_hydraulics/test/tests/base/simulation/err.no_smp.i)
(modules/thermal_hydraulics/test/tests/postprocessors/flow_junction_flux_1phase/flow_junction_flux_1phase.i)
(modules/thermal_hydraulics/test/tests/misc/mesh_only/test.i)
(modules/thermal_hydraulics/test/tests/misc/restart_1phase/test.i)
(modules/thermal_hydraulics/test/tests/components/volume_junction_1phase/phy.form_loss.i)
(modules/thermal_hydraulics/test/tests/components/volume_junction_1phase/equal_area_with_junction.i)
(modules/thermal_hydraulics/test/tests/problems/brayton_cycle/recuperated_brayton_cycle.i)
(modules/thermal_hydraulics/test/tests/problems/william_louis/4pipes_closed.i)
(modules/thermal_hydraulics/test/tests/problems/william_louis/3pipes_open.i)
(modules/thermal_hydraulics/test/tests/problems/abrupt_area_change_liquid/with_junction.i)
(modules/thermal_hydraulics/test/tests/components/volume_junction_1phase/phy.unequal_area.i)
(modules/thermal_hydraulics/test/tests/components/volume_junction_1phase/t_junction_1phase.i)
(modules/thermal_hydraulics/test/tests/output/vector_velocity/test.i)
(modules/thermal_hydraulics/test/tests/components/volume_junction_1phase/junction_with_calorifically_imperfect_gas.i)
(modules/thermal_hydraulics/test/tests/misc/coupling_mD_flow/thm_non_overlapping.i)
(modules/thermal_hydraulics/test/tests/misc/displaced_components/displaced_components.i)
(modules/thermal_hydraulics/tutorials/single_phase_flow/04_loop.i)
(modules/thermal_hydraulics/test/tests/components/pump_1phase/pump_loop.i)
(modules/thermal_hydraulics/test/tests/components/gate_valve_1phase/gate_valve_1phase.i)
(modules/thermal_hydraulics/test/tests/misc/initial_from_file/volume_junction/base.i)
(modules/thermal_hydraulics/test/tests/components/volume_junction_1phase/phy.shower.i)
(modules/thermal_hydraulics/test/tests/misc/uniform_refine/test.i)

Child Objects

(modules/thermal_hydraulics/include/components/JunctionParallelChannels1Phase.h)
(modules/thermal_hydraulics/include/components/ShaftConnectedCompressor1Phase.h)
(modules/thermal_hydraulics/include/components/ShaftConnectedTurbine1Phase.h)
(modules/thermal_hydraulics/include/components/ShaftConnectedPump1Phase.h)
(modules/thermal_hydraulics/include/components/Pump1Phase.h)

References

Seok Hong and Chongam Kim. A new finite volume method on junction coupling and boundary treatment for flow network system analyses. International Journal for Numerical Methods in Fluids, 65:707 – 742, 02 2011. doi:10.1002/fld.2212.

@article{hong2011,
    author = "Hong, Seok and Kim, Chongam",
    year = "2011",
    month = "02",
    pages = "707 - 742",
    title = "A new finite volume method on junction coupling and boundary treatment for flow network system analyses",
    volume = "65",
    journal = "International Journal for Numerical Methods in Fluids",
    doi = "10.1002/fld.2212"
}

(modules/thermal_hydraulics/test/tests/problems/three_pipe_shock/three_pipe_shock.i)

# Test 8 from the following reference:
#
#   F. Daude, P. Galon. A Finite-Volume approach for compressible single- and
#   two-phase flows in flexible pipelines with fluid-structure interaction.
#   Journal of Computational Physics 362 (2018) 375-408.

L1 = 10
L2 = 3
L3 = 5

xJ = ${L1}
x_p1 = ${fparse xJ - 1.05}
x_p2 = ${fparse xJ + 0.15}
x_p3 = ${fparse xJ + 0.95}

N1 = 1000
N2 = 300
N3 = 500

D1 = 0.35682482
D2 = 0.19544100
D3 = 0.35682482

A1 = ${fparse 0.25 * pi * D1^2}
A2 = ${fparse 0.25 * pi * D2^2}
A3 = ${fparse 0.25 * pi * D3^2}
AJ = ${fparse A1 + A2 + A3}
RJ = ${fparse sqrt(AJ / (4 * pi))} # A = 4 pi R^2
VJ = ${fparse 4/3 * pi * RJ^3}

y2 = 1
y3 = -1

gamma = 2.23
p_inf = 1e9 # denoted by "pi" in reference
q = 0
cv = 2500 # arbitrary value; not given in reference

CFL = 0.8
t_end = 0.01

p_out = 80e5

initial_p = ${p_out}
initial_T = 327.1864956 # reference has rho = 1001.89 kg/m^3
initial_vel1 = 1
initial_vel2 = 0.769
initial_vel3 = 0.769

[GlobalParams]
  gravity_vector = '0 0 0'

  initial_T = ${initial_T}
  initial_p = ${initial_p}

  fp = fp
  closures = closures
  f = 0

  rdg_slope_reconstruction = none
  scaling_factor_1phase = '1 1 1e-5'
[]

[FluidProperties]
  [fp]
    type = StiffenedGasFluidProperties
    gamma = ${gamma}
    p_inf = ${p_inf}
    q = ${q}
    cv = ${cv}
  []
[]

[Closures]
  [closures]
    type = Closures1PhaseSimple
  []
[]

[Components]
  [pipe1]
    type = FlowChannel1Phase
    position = '0 0 0'
    orientation = '1 0 0'
    length = ${L1}
    n_elems = ${N1}
    A = ${A1}
    initial_vel = ${initial_vel1}
  []
  [pipe2]
    type = FlowChannel1Phase
    position = '${xJ} ${y2} 0'
    orientation = '1 0 0'
    length = ${L2}
    n_elems = ${N2}
    A = ${A2}
    initial_vel = ${initial_vel2}
  []
  [pipe3]
    type = FlowChannel1Phase
    position = '${xJ} ${y3} 0'
    orientation = '1 0 0'
    length = ${L3}
    n_elems = ${N3}
    A = ${A3}
    initial_vel = ${initial_vel3}
  []

  [junction]
    type = VolumeJunction1Phase
    connections = 'pipe1:out pipe2:in pipe3:in'
    position = '${xJ} 0 0'
    volume = ${VJ}
    initial_vel_x = ${initial_vel2} # ?
    initial_vel_y = 0
    initial_vel_z = 0
    scaling_factor_rhoEV = 1e-5
    apply_velocity_scaling = true
  []

  [outlet1]
    type = Outlet1Phase
    input = 'pipe1:in'
    p = ${p_out}
  []
  [outlet2]
    type = Outlet1Phase
    input = 'pipe2:out'
    p = ${p_out}
  []
  [wall3]
    type = SolidWall1Phase
    input = 'pipe3:out'
  []
[]

[Preconditioning]
  [pc]
    type = SMP
    full = true
  []
[]

[Postprocessors]
  [dt_cfl]
    type = ADCFLTimeStepSize
    CFL = ${CFL}
    vel_names = 'vel'
    c_names = 'c'
  []
  [p1]
    type = PointValue
    variable = p
    point = '${x_p1} 0 0'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [p2]
    type = PointValue
    variable = p
    point = '${x_p2} ${y2} 0'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [p3]
    type = PointValue
    variable = p
    point = '${x_p3} ${y3} 0'
    execute_on = 'INITIAL TIMESTEP_END'
  []
[]

[Executioner]
  type = Transient

  start_time = 0
  end_time = ${t_end}
  [TimeStepper]
    type = PostprocessorDT
    postprocessor = dt_cfl
  []
  [TimeIntegrator]
    type = ActuallyExplicitEuler
  []

  solve_type = LINEAR

  petsc_options_iname = '-pc_type'
  petsc_options_value = ' lu     '

  l_tol = 1e-4
  l_max_its = 10
[]

[Times]
  [output_times]
    type = TimeIntervalTimes
    time_interval = 1e-4
  []
[]

[Outputs]
  file_base = 'three_pipe_shock'
  [csv]
    type = CSV
    show = 'p1 p2 p3'
    sync_only = true
    sync_times_object = output_times
  []
[]

(modules/thermal_hydraulics/tutorials/single_phase_flow/06_custom_closures.i)

T_in = 300. # K
m_dot_in = 1e-2 # kg/s
press = 10e5 # Pa

# core parameters
core_length = 1. # m
core_n_elems = 25
core_dia = '${units 2. cm -> m}'
core_pitch = '${units 8.7 cm -> m}'
A_core = '${fparse core_pitch^2 - 0.25 *pi * core_dia^2}'
P_wet_core = '${fparse 4*core_pitch + pi * core_dia}'
Dh_core = '${fparse 4 * A_core / P_wet_core}'

# pipe parameters
pipe_dia = '${units 10. cm -> m}'
A_pipe = '${fparse 0.25 * pi * pipe_dia^2}'

tot_power = 2000 # W

# heat exchanger parameters
hx_dia_inner = '${units 12. cm -> m}'
hx_wall_thickness = '${units 5. mm -> m}'
hx_dia_outer = '${units 50. cm -> m}'
hx_radius_wall = '${fparse hx_dia_inner / 2. + hx_wall_thickness}'
hx_length = 1.5 # m
hx_n_elems = 25

m_dot_sec_in = 1. # kg/s

[GlobalParams]
  initial_p = ${press}
  initial_vel = 0.0001
  initial_T = ${T_in}
  initial_vel_x = 0
  initial_vel_y = 0
  initial_vel_z = 0
  gravity_vector = '0 0 0'

  rdg_slope_reconstruction = minmod
  scaling_factor_1phase = '1 1e-2 1e-4'
  scaling_factor_rhoV = 1
  scaling_factor_rhouV = 1e-2
  scaling_factor_rhovV = 1e-2
  scaling_factor_rhowV = 1e-2
  scaling_factor_rhoEV = 1e-4
  closures = thm_closures
  fp = he
[]

[Functions]
  [m_dot_sec_fn]
    type = PiecewiseLinear
    xy_data = '
      0    0
      10 ${m_dot_sec_in}'
  []
[]

[FluidProperties]
  [he]
    type = IdealGasFluidProperties
    molar_mass = 4e-3
    gamma = 1.67
    k = 0.2556
    mu = 3.22639e-5
  []

  [water]
    type = StiffenedGasFluidProperties
    gamma = 2.35
    cv = 1816.0
    q = -1.167e6
    p_inf = 1.0e9
    q_prime = 0
  []
[]

[Closures]
  [thm_closures]
    type = Closures1PhaseTHM
  []
  [none_closures]
    type = Closures1PhaseNone
  []
[]

[Materials]
  [Re_mat]
    type = ADReynoldsNumberMaterial
    Re = Re
    rho = rho
    vel = vel
    D_h = D_h
    mu = mu
    block = hx/pri
  []
  [f_mat]
    type = ADParsedMaterial
    property_name = f_D
    constant_names = 'a b c'
    constant_expressions = '1 0.1 -0.5'
    material_property_names = 'Re'
    expression = 'a + b * Re^c'
    block = hx/pri
  []
  [Pr_mat]
    type = ADPrandtlNumberMaterial
    Pr = Pr
    cp = cp
    mu = mu
    k = k
    block = hx/pri
  []
  [Nu_mat]
    type = ADParsedMaterial
    property_name = 'Nu'
    constant_names = 'a b c'
    constant_expressions = '0.03 0.9 0.5'
    material_property_names = 'Re Pr'
    expression = 'a * Re ^b * Pr^c'
    block = hx/pri
  []
  [Hw_mat]
    type = ADConvectiveHeatTransferCoefficientMaterial
    D_h = D_h
    k = k
    Nu = Nu
    Hw = Hw
    block = hx/pri
  []
[]
[SolidProperties]
  [steel]
    type = ThermalFunctionSolidProperties
    rho = 8050
    k = 45
    cp = 466
  []
[]

[Components]
  [total_power]
    type = TotalPower
    power = ${tot_power}
  []
  [up_pipe_1]
    type = FlowChannel1Phase
    position = '0 0 0'
    orientation = '0 0 1'
    length = 0.5
    n_elems = 15
    A = ${A_pipe}
    D_h = ${pipe_dia}
  []

  [jct1]
    type = JunctionParallelChannels1Phase
    position = '0 0 0.5'
    connections = 'up_pipe_1:out core_chan:in'
    volume = 1e-5
    use_scalar_variables = false
  []
  [core_chan]
    type = FlowChannel1Phase
    position = '0 0 0.5'
    orientation = '0 0 1'
    length = ${core_length}
    n_elems = ${core_n_elems}
    roughness = .0001
    A = ${A_core}
    D_h = ${Dh_core}
  []

  [core_hs]
    type = HeatStructureCylindrical
    position = '0 0 0.5'
    orientation = '0 0 1'
    length = ${core_length}
    n_elems = ${core_n_elems}
    names = 'block'
    widths = '${fparse core_dia / 2.}'
    solid_properties = 'steel'
    solid_properties_T_ref = '300'
    n_part_elems = 3
  []

  [core_heating]
    type = HeatSourceFromTotalPower
    hs = core_hs
    regions = block
    power = total_power
  []

  [core_ht]
    type = HeatTransferFromHeatStructure1Phase
    flow_channel = core_chan
    hs = core_hs
    hs_side = outer
    P_hf = '${fparse pi * core_dia}'
  []

  [jct2]
    type = JunctionParallelChannels1Phase
    position = '0 0 1.5'
    connections = 'core_chan:out up_pipe_2:in'
    volume = 1e-5
    use_scalar_variables = false
  []

  [up_pipe_2]
    type = FlowChannel1Phase
    position = '0 0 1.5'
    orientation = '0 0 1'
    length = 0.5
    n_elems = 10
    A = ${A_pipe}
    D_h = ${pipe_dia}
  []

  [jct3]
    type = JunctionOneToOne1Phase
    connections = 'up_pipe_2:out top_pipe_1:in'
  []

  [top_pipe_1]
    type = FlowChannel1Phase
    position = '0 0 2'
    orientation = '1 0 0'
    length = 0.5
    n_elems = 10
    A = ${A_pipe}
    D_h = ${pipe_dia}
  []

  [top_pipe_2]
    type = FlowChannel1Phase
    position = '0.5 0 2'
    orientation = '1 0 0'
    length = 0.5
    n_elems = 10
    A = ${A_pipe}
    D_h = ${pipe_dia}
  []

  [jct4]
    type = VolumeJunction1Phase
    position = '0.5 0 2'
    volume = 1e-5
    connections = 'top_pipe_1:out top_pipe_2:in press_pipe:in'
    use_scalar_variables = false
  []

  [press_pipe]
    type = FlowChannel1Phase
    position = '0.5 0 2'
    orientation = '0 1 0'
    length = 0.2
    n_elems = 5
    A = ${A_pipe}
    D_h = ${pipe_dia}
  []

  [pressurizer]
    type = InletStagnationPressureTemperature1Phase
    p0 = ${press}
    T0 = ${T_in}
    input = press_pipe:out
  []

  [jct5]
    type = JunctionOneToOne1Phase
    connections = 'top_pipe_2:out down_pipe_1:in'
  []

  [down_pipe_1]
    type = FlowChannel1Phase
    position = '1 0 2'
    orientation = '0 0 -1'
    length = 0.25
    A = ${A_pipe}
    n_elems = 5
  []

  [jct6]
    type = JunctionParallelChannels1Phase
    position = '1 0 1.75'
    connections = 'down_pipe_1:out hx/pri:in'
    volume = 1e-5
    use_scalar_variables = false
  []

  [hx]
    [pri]
      type = FlowChannel1Phase
      position = '1 0 1.75'
      orientation = '0 0 -1'
      length = ${hx_length}
      n_elems = ${hx_n_elems}
      roughness = 1e-5
      A = '${fparse pi * hx_dia_inner * hx_dia_inner / 4.}'
      D_h = ${hx_dia_inner}
      closures = none_closures
    []

    [ht_pri]
      type = HeatTransferFromHeatStructure1Phase
      hs = hx/wall
      hs_side = inner
      flow_channel = hx/pri
      P_hf = '${fparse pi * hx_dia_inner}'
    []

    [wall]
      type = HeatStructureCylindrical
      position = '1 0 1.75'
      orientation = '0 0 -1'
      length = ${hx_length}
      n_elems = ${hx_n_elems}
      widths = '${hx_wall_thickness}'
      n_part_elems = '3'
      solid_properties = 'steel'
      solid_properties_T_ref = '300'
      names = '0'
      inner_radius = '${fparse hx_dia_inner / 2.}'
    []

    [ht_sec]
      type = HeatTransferFromHeatStructure1Phase
      hs = hx/wall
      hs_side = outer
      flow_channel = hx/sec
      P_hf = '${fparse 2 * pi * hx_radius_wall}'
    []

    [sec]
      type = FlowChannel1Phase
      position = '${fparse 1 + hx_wall_thickness} 0 0.25'
      orientation = '0 0 1'
      length = ${hx_length}
      n_elems = ${hx_n_elems}
      A = '${fparse pi * (hx_dia_outer * hx_dia_outer / 4. - hx_radius_wall * hx_radius_wall)}'
      D_h = '${fparse hx_dia_outer - (2 * hx_radius_wall)}'
      fp = water
      initial_T = 300
    []
  []

  [jct7]
    type = JunctionParallelChannels1Phase
    position = '1 0 0.5'
    connections = 'hx/pri:out down_pipe_2:in'
    volume = 1e-5
    use_scalar_variables = false
  []

  [down_pipe_2]
    type = FlowChannel1Phase
    position = '1 0 0.25'
    orientation = '0 0 -1'
    length = 0.25
    n_elems = 10
    A = ${A_pipe}
    D_h = ${pipe_dia}
  []

  [jct8]
    type = JunctionOneToOne1Phase
    connections = 'down_pipe_2:out bottom_1:in'
  []

  [bottom_1]
    type = FlowChannel1Phase
    position = '1 0 0'
    orientation = '-1 0 0'
    length = 0.5
    n_elems = 5
    A = ${A_pipe}
    D_h = ${pipe_dia}
  []

  [pump]
    type = Pump1Phase
    position = '0.5 0 0'
    connections = 'bottom_1:out bottom_2:in'
    volume = 1e-4
    A_ref = ${A_pipe}
    head = 0
    use_scalar_variables = false
  []

  [bottom_2]
    type = FlowChannel1Phase
    position = '0.5 0 0'
    orientation = '-1 0 0'
    length = 0.5
    n_elems = 5
    A = ${A_pipe}
    D_h = ${pipe_dia}
  []

  [jct9]
    type = JunctionOneToOne1Phase
    connections = 'bottom_2:out up_pipe_1:in'
  []

  [inlet_sec]
    type = InletMassFlowRateTemperature1Phase
    input = 'hx/sec:in'
    m_dot = 0
    T = 300
  []

  [outlet_sec]
    type = Outlet1Phase
    input = 'hx/sec:out'
    p = 1e5
  []
[]

[ControlLogic]
  [set_point]
    type = GetFunctionValueControl
    function = ${m_dot_in}
  []

  [pid]
    type = PIDControl
    initial_value = 0.0
    set_point = set_point:value
    input = m_dot_pump
    K_p = 1.
    K_i = 4.
    K_d = 0
  []

  [set_pump_head]
    type = SetComponentRealValueControl
    component = pump
    parameter = head
    value = pid:output
  []

  [m_dot_sec_inlet_ctrl]
    type = GetFunctionValueControl
    function = m_dot_sec_fn
  []

  [set_m_dot_sec_ctrl]
    type = SetComponentRealValueControl
    component = inlet_sec
    parameter = m_dot
    value = m_dot_sec_inlet_ctrl:value
  []
[]

[Postprocessors]
  [power_to_coolant]
    type = ADHeatRateConvection1Phase
    block = core_chan
    P_hf = '${fparse pi *core_dia}'
  []

  [m_dot_pump]
    type = ADFlowJunctionFlux1Phase
    boundary = core_chan:in
    connection_index = 1
    equation = mass
    junction = jct7
  []

  [core_T_out]
    type = SideAverageValue
    boundary = core_chan:out
    variable = T
  []

  [core_p_in]
    type = SideAverageValue
    boundary = core_chan:in
    variable = p
  []

  [core_p_out]
    type = SideAverageValue
    boundary = core_chan:out
    variable = p
  []

  [core_delta_p]
    type = ParsedPostprocessor
    pp_names = 'core_p_in core_p_out'
    expression = 'core_p_in - core_p_out'
  []

  [hx_pri_T_out]
    type = SideAverageValue
    boundary = hx/pri:out
    variable = T
  []

  [hx_sec_T_in]
    type = SideAverageValue
    boundary = inlet_sec
    variable = T
  []

  [hx_sec_T_out]
    type = SideAverageValue
    boundary = outlet_sec
    variable = T
  []
  [m_dot_sec]
    type = ADFlowBoundaryFlux1Phase
    boundary = inlet_sec
    equation = mass
  []

  [Hw_hx_pri]
    type = ADElementAverageMaterialProperty
    mat_prop = Hw
    block = hx/pri
  []
  [fD_hx_pri]
    type = ADElementAverageMaterialProperty
    mat_prop = f_D
    block = hx/pri
  []

[]

[Preconditioning]
  [pc]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  start_time = 0

  [TimeStepper]
    type = IterationAdaptiveDT
    dt = 1
  []
  dtmax = 5
  end_time = 500

  line_search = basic
  solve_type = NEWTON

  petsc_options_iname = '-pc_type'
  petsc_options_value = 'lu'

  nl_rel_tol = 1e-8
  nl_abs_tol = 1e-8
  nl_max_its = 25

[]

[Outputs]
  exodus = true

  [console]
    type = Console
    max_rows = 1
    outlier_variable_norms = false
  []
  print_linear_residuals = false
[]

(modules/thermal_hydraulics/test/tests/components/volume_junction_1phase/phy.deadend.i)

# Junction between 3 pipes, 1 of which goes to a dead-end. In the steady-state,
# no flow should go into the dead-end pipe.

[GlobalParams]
  gravity_vector = '0 0 0'

  scaling_factor_1phase = '1 1 1e-5'

  initial_T = 250
  initial_p = 1e5
  initial_vel_x = 1
  initial_vel_y = 0
  initial_vel_z = 0

  closures = simple_closures
[]

[AuxVariables]
  [p0]
    block = 'inlet_pipe outlet_pipe deadend_pipe'
    family = MONOMIAL
    order = CONSTANT
  []
[]

[AuxKernels]
  [p0_kernel]
    type = StagnationPressureAux
    variable = p0
    fp = eos
    e = e
    v = v
    vel = vel
  []
[]

[FluidProperties]
  [eos]
    type = StiffenedGasFluidProperties
    gamma = 1.4
    cv = 725
    q = 0
    q_prime = 0
    p_inf = 0
  []
[]

[Closures]
  [simple_closures]
    type = Closures1PhaseSimple
  []
[]

[Functions]
  [T0]
    type = ParsedFunction
    expression = 'if (x < 1, 300 + 50 * sin(2*pi*x + 1.5*pi), 250)'
  []
[]

[Components]
  [inlet]
    type = InletDensityVelocity1Phase
    input = 'inlet_pipe:in'
    rho = 1.37931034483
    vel = 1
  []

  [inlet_pipe]
    type = FlowChannel1Phase
    fp = eos

    position = '0 0 0'
    orientation = '1 0 0'
    length = 1
    A = 1

    f = 0

    initial_T = T0
    initial_p = 1e5
    initial_vel = 1

    n_elems = 20
  []

  [junction1]
    type = VolumeJunction1Phase
    connections = 'inlet_pipe:out deadend_pipe:in outlet_pipe:in'
    position = '1 0 0'
    volume = 1e-8
    use_scalar_variables = false
  []

  [outlet_pipe]
    type = FlowChannel1Phase
    fp = eos

    position = '1 0 0'
    orientation = '1 0 0'
    length = 1
    A = 1

    f = 0

    initial_T = 250
    initial_p = 1e5
    initial_vel = 1

    n_elems = 20
  []

  [outlet]
    type = Outlet1Phase
    input = 'outlet_pipe:out'
    p = 1e5
  []

  [deadend_pipe]
    type = FlowChannel1Phase
    fp = eos

    position = '1 0 0'
    orientation = '0 1 0'
    length = 1
    A = 1

    f = 0

    initial_T = 250
    initial_p = 1e5
    initial_vel = 0

    n_elems = 20
  []

  [deadend]
    type = SolidWall1Phase
    input = 'deadend_pipe:out'
  []
[]

[Preconditioning]
  [pc]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  scheme = 'bdf2'

  solve_type = 'NEWTON'
  line_search = 'basic'
  nl_rel_tol = 0
  nl_abs_tol = 1e-6
  nl_max_its = 10

  l_tol = 1e-6
  l_max_its = 10

  petsc_options_iname = '-pc_type'
  petsc_options_value = 'lu'

  start_time = 0
  end_time = 5
  dt = 0.1

  abort_on_solve_fail = true
[]

[Postprocessors]
  # These post-processors are used for testing that the stagnation pressure in
  # the dead-end pipe is equal to the inlet stagnation pressure.
  [p0_inlet]
    type = SideAverageValue
    variable = p0
    boundary = inlet_pipe:in
  []
  [p0_deadend]
    type = SideAverageValue
    variable = p0
    boundary = deadend_pipe:out
  []
  [test_rel_err]
    type = RelativeDifferencePostprocessor
    value1 = p0_deadend
    value2 = p0_inlet
  []
[]

[Outputs]
  [out]
    type = CSV
    show = test_rel_err
    sync_only = true
    sync_times = '1 2 3 4 5'
  []
  velocity_as_vector = false
[]

(modules/thermal_hydraulics/test/tests/components/volume_junction_1phase/err.missing_ics.i)

[GlobalParams]
  gravity_vector = '0 0 0'

  A = 1e-4
  f = 0
  fp = fp

  closures = simple_closures
[]

[FluidProperties]
  [fp]
    type = StiffenedGasFluidProperties
    gamma = 1.4
    cv = 725
    p_inf = 0
    q = 0
    q_prime = 0
  []
[]

[Closures]
  [simple_closures]
    type = Closures1PhaseSimple
  []
[]

[Components]
  [inlet]
    type = InletStagnationPressureTemperature1Phase
    input = 'pipe1:in'
    # Stagnation property with p = 1e5 Pa, T = 250 K, vel = 1 m/s
    p0 = 100000.68965687
    T0 = 250.00049261084
  []

  [pipe1]
    type = FlowChannel1Phase

    position = '0 0 0'
    orientation = '1 0 0'
    length = 1
    n_elems = 2

    initial_p = 1e5
    initial_T = 250
    initial_vel = 0
  []

  [junction]
    type = VolumeJunction1Phase
    connections = 'pipe1:out pipe2:in'
    position = '1.02 0 0'
    volume = 0.1
    use_scalar_variables = false
  []

  [pipe2]
    type = FlowChannel1Phase

    position = '1.04 0 0'
    orientation = '1 0 0'
    length = 0.96
    n_elems = 2

    initial_p = 1e5
    initial_T = 250
    initial_vel = 0
  []

  [outlet]
    type = Outlet1Phase
    input = 'pipe2:out'
    p = 1e5
  []
[]

[Executioner]
  type = Transient
  abort_on_solve_fail = true
[]

(modules/thermal_hydraulics/tutorials/single_phase_flow/05_secondary_side.i)

T_in = 300. # K
m_dot_in = 1e-2 # kg/s
press = 10e5 # Pa

# core parameters
core_length = 1. # m
core_n_elems = 25
core_dia = '${units 2. cm -> m}'
core_pitch = '${units 8.7 cm -> m}'
A_core = '${fparse core_pitch^2 - 0.25 *pi * core_dia^2}'
P_wet_core = '${fparse 4*core_pitch + pi * core_dia}'
Dh_core = '${fparse 4 * A_core / P_wet_core}'

# pipe parameters
pipe_dia = '${units 10. cm -> m}'
A_pipe = '${fparse 0.25 * pi * pipe_dia^2}'

tot_power = 2000 # W

# heat exchanger parameters
hx_dia_inner = '${units 12. cm -> m}'
hx_wall_thickness = '${units 5. mm -> m}'
hx_dia_outer = '${units 50. cm -> m}'
hx_radius_wall = '${fparse hx_dia_inner / 2. + hx_wall_thickness}'
hx_length = 1.5 # m
hx_n_elems = 25

m_dot_sec_in = 1. # kg/s

[GlobalParams]
  initial_p = ${press}
  initial_vel = 0.0001
  initial_T = ${T_in}
  initial_vel_x = 0
  initial_vel_y = 0
  initial_vel_z = 0
  gravity_vector = '0 0 0'

  rdg_slope_reconstruction = minmod
  scaling_factor_1phase = '1 1e-2 1e-4'
  scaling_factor_rhoV = 1
  scaling_factor_rhouV = 1e-2
  scaling_factor_rhovV = 1e-2
  scaling_factor_rhowV = 1e-2
  scaling_factor_rhoEV = 1e-4
  closures = thm_closures
  fp = he
[]

[Functions]
  [m_dot_sec_fn]
    type = PiecewiseLinear
    xy_data = '
      0    0
      10 ${m_dot_sec_in}'
  []
[]

[FluidProperties]
  [he]
    type = IdealGasFluidProperties
    molar_mass = 4e-3
    gamma = 1.67
    k = 0.2556
    mu = 3.22639e-5
  []

  [water]
    type = StiffenedGasFluidProperties
    gamma = 2.35
    cv = 1816.0
    q = -1.167e6
    p_inf = 1.0e9
    q_prime = 0
  []
[]

[Closures]
  [thm_closures]
    type = Closures1PhaseTHM
  []
[]

[SolidProperties]
  [steel]
    type = ThermalFunctionSolidProperties
    rho = 8050
    k = 45
    cp = 466
  []
[]

[Components]
  [total_power]
    type = TotalPower
    power = ${tot_power}
  []
  [up_pipe_1]
    type = FlowChannel1Phase
    position = '0 0 0'
    orientation = '0 0 1'
    length = 0.5
    n_elems = 15
    A = ${A_pipe}
    D_h = ${pipe_dia}
  []

  [jct1]
    type = JunctionParallelChannels1Phase
    position = '0 0 0.5'
    connections = 'up_pipe_1:out core_chan:in'
    volume = 1e-5
    use_scalar_variables = false
  []
  [core_chan]
    type = FlowChannel1Phase
    position = '0 0 0.5'
    orientation = '0 0 1'
    length = ${core_length}
    n_elems = ${core_n_elems}
    roughness = .0001
    A = ${A_core}
    D_h = ${Dh_core}
  []

  [core_hs]
    type = HeatStructureCylindrical
    position = '0 0 0.5'
    orientation = '0 0 1'
    length = ${core_length}
    n_elems = ${core_n_elems}
    names = 'block'
    widths = '${fparse core_dia / 2.}'
    solid_properties = 'steel'
    solid_properties_T_ref = '300'
    n_part_elems = 3
  []

  [core_heating]
    type = HeatSourceFromTotalPower
    hs = core_hs
    regions = block
    power = total_power
  []

  [core_ht]
    type = HeatTransferFromHeatStructure1Phase
    flow_channel = core_chan
    hs = core_hs
    hs_side = outer
    P_hf = '${fparse pi * core_dia}'
  []

  [jct2]
    type = JunctionParallelChannels1Phase
    position = '0 0 1.5'
    connections = 'core_chan:out up_pipe_2:in'
    volume = 1e-5
    use_scalar_variables = false
  []

  [up_pipe_2]
    type = FlowChannel1Phase
    position = '0 0 1.5'
    orientation = '0 0 1'
    length = 0.5
    n_elems = 10
    A = ${A_pipe}
    D_h = ${pipe_dia}
  []

  [jct3]
    type = JunctionOneToOne1Phase
    connections = 'up_pipe_2:out top_pipe_1:in'
  []

  [top_pipe_1]
    type = FlowChannel1Phase
    position = '0 0 2'
    orientation = '1 0 0'
    length = 0.5
    n_elems = 10
    A = ${A_pipe}
    D_h = ${pipe_dia}
  []

  [top_pipe_2]
    type = FlowChannel1Phase
    position = '0.5 0 2'
    orientation = '1 0 0'
    length = 0.5
    n_elems = 10
    A = ${A_pipe}
    D_h = ${pipe_dia}
  []

  [jct4]
    type = VolumeJunction1Phase
    position = '0.5 0 2'
    volume = 1e-5
    connections = 'top_pipe_1:out top_pipe_2:in press_pipe:in'
    use_scalar_variables = false
  []

  [press_pipe]
    type = FlowChannel1Phase
    position = '0.5 0 2'
    orientation = '0 1 0'
    length = 0.2
    n_elems = 5
    A = ${A_pipe}
    D_h = ${pipe_dia}
  []

  [pressurizer]
    type = InletStagnationPressureTemperature1Phase
    p0 = ${press}
    T0 = ${T_in}
    input = press_pipe:out
  []

  [jct5]
    type = JunctionOneToOne1Phase
    connections = 'top_pipe_2:out down_pipe_1:in'
  []

  [down_pipe_1]
    type = FlowChannel1Phase
    position = '1 0 2'
    orientation = '0 0 -1'
    length = 0.25
    A = ${A_pipe}
    n_elems = 5
  []

  [jct6]
    type = JunctionParallelChannels1Phase
    position = '1 0 1.75'
    connections = 'down_pipe_1:out hx/pri:in'
    volume = 1e-5
    use_scalar_variables = false
  []

  [hx]
    [pri]
      type = FlowChannel1Phase
      position = '1 0 1.75'
      orientation = '0 0 -1'
      length = ${hx_length}
      n_elems = ${hx_n_elems}
      roughness = 1e-5
      A = '${fparse pi * hx_dia_inner * hx_dia_inner / 4.}'
      D_h = ${hx_dia_inner}
    []

    [ht_pri]
      type = HeatTransferFromHeatStructure1Phase
      hs = hx/wall
      hs_side = inner
      flow_channel = hx/pri
      P_hf = '${fparse pi * hx_dia_inner}'
    []

    [wall]
      type = HeatStructureCylindrical
      position = '1 0 1.75'
      orientation = '0 0 -1'
      length = ${hx_length}
      n_elems = ${hx_n_elems}
      widths = '${hx_wall_thickness}'
      n_part_elems = '3'
      solid_properties = 'steel'
      solid_properties_T_ref = '300'
      names = '0'
      inner_radius = '${fparse hx_dia_inner / 2.}'
    []

    [ht_sec]
      type = HeatTransferFromHeatStructure1Phase
      hs = hx/wall
      hs_side = outer
      flow_channel = hx/sec
      P_hf = '${fparse 2 * pi * hx_radius_wall}'
    []

    [sec]
      type = FlowChannel1Phase
      position = '${fparse 1 + hx_wall_thickness} 0 0.25'
      orientation = '0 0 1'
      length = ${hx_length}
      n_elems = ${hx_n_elems}
      A = '${fparse pi * (hx_dia_outer * hx_dia_outer / 4. - hx_radius_wall * hx_radius_wall)}'
      D_h = '${fparse hx_dia_outer - (2 * hx_radius_wall)}'
      fp = water
      initial_T = 300
    []
  []

  [jct7]
    type = JunctionParallelChannels1Phase
    position = '1 0 0.5'
    connections = 'hx/pri:out down_pipe_2:in'
    volume = 1e-5
    use_scalar_variables = false
  []

  [down_pipe_2]
    type = FlowChannel1Phase
    position = '1 0 0.25'
    orientation = '0 0 -1'
    length = 0.25
    n_elems = 10
    A = ${A_pipe}
    D_h = ${pipe_dia}
  []

  [jct8]
    type = JunctionOneToOne1Phase
    connections = 'down_pipe_2:out bottom_1:in'
  []

  [bottom_1]
    type = FlowChannel1Phase
    position = '1 0 0'
    orientation = '-1 0 0'
    length = 0.5
    n_elems = 5
    A = ${A_pipe}
    D_h = ${pipe_dia}
  []

  [pump]
    type = Pump1Phase
    position = '0.5 0 0'
    connections = 'bottom_1:out bottom_2:in'
    volume = 1e-4
    A_ref = ${A_pipe}
    head = 0
    use_scalar_variables = false
  []

  [bottom_2]
    type = FlowChannel1Phase
    position = '0.5 0 0'
    orientation = '-1 0 0'
    length = 0.5
    n_elems = 5
    A = ${A_pipe}
    D_h = ${pipe_dia}
  []

  [jct9]
    type = JunctionOneToOne1Phase
    connections = 'bottom_2:out up_pipe_1:in'
  []

  [inlet_sec]
    type = InletMassFlowRateTemperature1Phase
    input = 'hx/sec:in'
    m_dot = 0
    T = 300
  []

  [outlet_sec]
    type = Outlet1Phase
    input = 'hx/sec:out'
    p = 1e5
  []
[]

[ControlLogic]
  [set_point]
    type = GetFunctionValueControl
    function = ${m_dot_in}
  []

  [pid]
    type = PIDControl
    initial_value = 0.0
    set_point = set_point:value
    input = m_dot_pump
    K_p = 1.
    K_i = 4.
    K_d = 0
  []

  [set_pump_head]
    type = SetComponentRealValueControl
    component = pump
    parameter = head
    value = pid:output
  []

  [m_dot_sec_inlet_ctrl]
    type = GetFunctionValueControl
    function = m_dot_sec_fn
  []

  [set_m_dot_sec_ctrl]
    type = SetComponentRealValueControl
    component = inlet_sec
    parameter = m_dot
    value = m_dot_sec_inlet_ctrl:value
  []
[]

[Postprocessors]
  [power_to_coolant]
    type = ADHeatRateConvection1Phase
    block = core_chan
    P_hf = '${fparse pi *core_dia}'
  []

  [m_dot_pump]
    type = ADFlowJunctionFlux1Phase
    boundary = core_chan:in
    connection_index = 1
    equation = mass
    junction = jct7
  []

  [core_T_out]
    type = SideAverageValue
    boundary = core_chan:out
    variable = T
  []

  [core_p_in]
    type = SideAverageValue
    boundary = core_chan:in
    variable = p
  []

  [core_p_out]
    type = SideAverageValue
    boundary = core_chan:out
    variable = p
  []

  [core_delta_p]
    type = ParsedPostprocessor
    pp_names = 'core_p_in core_p_out'
    expression = 'core_p_in - core_p_out'
  []

  [hx_pri_T_out]
    type = SideAverageValue
    boundary = hx/pri:out
    variable = T
  []

  [hx_sec_T_in]
    type = SideAverageValue
    boundary = inlet_sec
    variable = T
  []

  [hx_sec_T_out]
    type = SideAverageValue
    boundary = outlet_sec
    variable = T
  []
  [m_dot_sec]
    type = ADFlowBoundaryFlux1Phase
    boundary = inlet_sec
    equation = mass
  []
[]

[Preconditioning]
  [pc]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  start_time = 0

  [TimeStepper]
    type = IterationAdaptiveDT
    dt = 1
  []
  dtmax = 5
  end_time = 500

  line_search = basic
  solve_type = NEWTON

  petsc_options_iname = '-pc_type'
  petsc_options_value = 'lu'

  nl_rel_tol = 0
  nl_abs_tol = 1e-8
  nl_max_its = 25

[]

[Outputs]
  exodus = true

  [console]
    type = Console
    max_rows = 1
    outlier_variable_norms = false
  []
  print_linear_residuals = false
[]

(modules/thermal_hydraulics/test/tests/misc/adapt/multiple_blocks.i)

[GlobalParams]
  gravity_vector = '0 0 0'

  initial_p = 1e5
  initial_T = 300
  initial_vel = 0

  closures = simple_closures
[]

[FluidProperties]
  [eos]
    type = StiffenedGasFluidProperties
    gamma = 2.35
    q = -1167e3
    q_prime = 0
    p_inf = 1.e9
    cv = 1816
  []
[]

[Closures]
  [simple_closures]
    type = Closures1PhaseSimple
  []
[]

[Components]
  [pipe1]
    type = FlowChannel1Phase
    fp = eos

    position = '0 0 0'
    orientation = '1 0 0'
    length = 1
    n_elems = 10
    A = 1

    f = 0
  []

  [pipe2]
    type = FlowChannel1Phase
    fp = eos

    position = '1 0 0'
    orientation = '1 0 0'
    length = 1
    n_elems = 10
    A = 1

    f = 0
  []

  [junction]
    type = VolumeJunction1Phase
    connections = 'pipe1:out pipe2:in'
    volume = 1e-5
    position = '1 0 0'

    initial_vel_x = 0
    initial_vel_y = 0
    initial_vel_z = 0

    use_scalar_variables = false
  []

  [inlet]
    type = InletStagnationPressureTemperature1Phase
    input = 'pipe1:in'
    # (p0, T0) for p = 1e5, T = 300, vel = 1
    p0 = 1.0049827846e+05
    T0 = 300.0000099
  []

  [outlet]
    type = Outlet1Phase
    input = 'pipe2:out'
    p = 1e5
  []
[]

[Preconditioning]
  [prec]
    type = SMP
    full = true
    petsc_options = '-pc_factor_shift_nonzero'
    petsc_options_iname = '-mat_fd_coloring_err'
    petsc_options_value = '1.e-10'
  []
[]

[Executioner]
  type = Transient

  start_time = 0
  dt = 1e-4
  num_steps = 5
  abort_on_solve_fail = true

  solve_type = 'PJFNK'
  nl_rel_tol = 0
  nl_abs_tol = 1e-5
  nl_max_its = 10

  l_tol = 1e-3
  l_max_its = 10

  [Adaptivity]
    initial_adaptivity = 0
    refine_fraction = 0.60
    coarsen_fraction = 0.10
    max_h_level = 3
  []

  automatic_scaling = true
[]

[Outputs]
  exodus = true
[]

(modules/thermal_hydraulics/test/tests/problems/natural_circulation/volume_junction.i)

# This version uses VolumeJunction1Phase

!include base_params.i

radius = ${fparse 0.5 * diam}
volume = ${fparse 4/3 * pi * radius^3}

!include base.i

[GlobalParams]
  initial_vel_x = 0
  initial_vel_y = 0
  initial_vel_z = 0

  scaling_factor_rhouV = 1e-2
  scaling_factor_rhovV = 1e-2
  scaling_factor_rhowV = 1e-2
  scaling_factor_rhoEV = 1e-5

  apply_velocity_scaling = false
[]

[Components]
  [junction_heated_top]
    type = VolumeJunction1Phase
    position = '0 0 1'
    volume = ${volume}
    connections = 'heated_pipe:out top_pipe:in'
  []
  [junction_top_cooled]
    type = VolumeJunction1Phase
    position = '1 0 1'
    volume = ${volume}
    connections = 'top_pipe:out cooled_pipe:in'
  []
  [junction_cooled_bottom]
    type = VolumeJunction1Phase
    position = '0 0 1'
    volume = ${volume}
    connections = 'cooled_pipe:out bottom_pipe:in'
  []
  [junction_bottom_heated]
    type = VolumeJunction1Phase
    position = '0 0 0'
    volume = ${volume}
    connections = 'bottom_pipe:out heated_pipe:in'
  []
[]

(modules/thermal_hydraulics/test/tests/base/simulation/err.no_smp.i)

[GlobalParams]
  gravity_vector = '0 0 9.81'

  initial_p = 1e5
  initial_T = 300
  initial_vel = 0
  initial_vel_x = 0
  initial_vel_y = 0
  initial_vel_z = 0

  fp = water

  closures = simple_closures
  f = 0
[]

[FluidProperties]
  [water]
    type = StiffenedGasFluidProperties
    gamma = 2.35
    cv = 1816.0
    q = -1.167e6
    p_inf = 1.0e9
    q_prime = 0
  []
[]

[Closures]
  [simple_closures]
    type = Closures1PhaseSimple
  []
[]

[Components]
  [inlet]
    type = InletMassFlowRateTemperature1Phase
    input = 'pipe1:in'
    m_dot = 1
    T = 300
  []

  [pipe1]
    type = FlowChannel1Phase
    position = '0 0 0'
    orientation = '1 0 0'
    length = '1'
    A = 1
    D_h = 1
    n_elems = 2
  []

  [jct1]
    type = VolumeJunction1Phase
    position = '1 0 0'
    volume = 1e-3
    connections = 'pipe1:out pipe2:in'
    use_scalar_variables = false
  []

  [pipe2]
    type = FlowChannel1Phase
    position = '1 0 0'
    orientation = '1 0 0'
    length = '1'
    A = 1
    D_h = 1
    n_elems = 2
  []

  [outlet]
    type = Outlet1Phase
    input = 'pipe2:out'
    p = 101325
  []
[]

[Executioner]
  type = Transient

  dt = 0.01
  num_steps = 2
[]

(modules/thermal_hydraulics/test/tests/postprocessors/flow_junction_flux_1phase/flow_junction_flux_1phase.i)

# This input file tests mass conservation at steady-state by looking at the
# net mass flux into the domain.

T_in = 523.0
m_dot = 100
p_out = 7e6

[GlobalParams]
  initial_p = ${p_out}
  initial_vel = 1
  initial_T = ${T_in}
  gravity_vector = '0 0 0'
  closures = simple_closures
  n_elems = 3
  f = 0
  scaling_factor_1phase = '1 1 1e-5'
[]

[FluidProperties]
  [fp]
    type = IdealGasFluidProperties
  []
[]

[Closures]
  [simple_closures]
    type = Closures1PhaseSimple
  []
[]

[Components]
  [inlet_bc]
    type = InletMassFlowRateTemperature1Phase
    input = 'inlet:in'
    m_dot = ${m_dot}
    T = ${T_in}
  []
  [inlet]
    type = FlowChannel1Phase
    fp = fp
    position = '0 0 11'
    orientation = '0 0 -1'
    length = 1
    A = 3
  []
  [inlet_plenum]
    type = VolumeJunction1Phase
    position = '0 0 10'
    initial_vel_x = 0
    initial_vel_y = 0
    initial_vel_z = 1
    connections = 'inlet:out channel1:in channel2:in'
    volume = 1
    scaling_factor_rhoEV = '1e-5'
    use_scalar_variables = false
  []
  [channel1]
    type = FlowChannel1Phase
    fp = fp
    position = '0 0 10'
    orientation = '0 0 -1'
    length = 10
    A = 4
    D_h = 1
  []
  [K_bypass]
    type = FormLossFromFunction1Phase
    K_prime = 500
    flow_channel = channel1
  []
  [channel2]
    type = FlowChannel1Phase
    fp = fp
    position = '0 0 10'
    orientation = '0 0 -1'
    length = 10
    A = 1
    D_h = 1
  []
  [outlet_plenum]
    type = VolumeJunction1Phase
    position = '0 0 0'
    initial_vel_x = 1
    initial_vel_y = 0
    initial_vel_z = 1
    connections = 'channel1:out channel2:out outlet:in'
    volume = 1
    scaling_factor_rhoEV = '1e-5'
    use_scalar_variables = false
  []
  [outlet]
    type = FlowChannel1Phase
    fp = fp
    position = '0 0 0'
    orientation = '0 0 -1'
    length = 1
    A = 1
  []
  [outlet_bc]
    type = Outlet1Phase
    p = ${p_out}
    input = 'outlet:out'
  []
[]

[Postprocessors]
  [inlet_in_m_dot]
    type = ADFlowBoundaryFlux1Phase
    boundary = 'inlet_bc'
    equation = mass
  []
  [inlet_out_m_dot]
    type = ADFlowJunctionFlux1Phase
    boundary = 'inlet:out'
    connection_index = 0
    junction = inlet_plenum
    equation = mass
  []

  [channel1_in_m_dot]
    type = ADFlowJunctionFlux1Phase
    boundary = 'channel1:in'
    connection_index = 1
    junction = inlet_plenum
    equation = mass
  []
  [channel1_out_m_dot]
    type = ADFlowJunctionFlux1Phase
    boundary = 'channel1:out'
    connection_index = 0
    junction = outlet_plenum
    equation = mass
  []

  [channel2_in_m_dot]
    type = ADFlowJunctionFlux1Phase
    boundary = 'channel2:in'
    connection_index = 2
    junction = inlet_plenum
    equation = mass
  []
  [channel2_out_m_dot]
    type = ADFlowJunctionFlux1Phase
    boundary = 'channel2:out'
    connection_index = 1
    junction = outlet_plenum
    equation = mass
  []

  [outlet_in_m_dot]
    type = ADFlowJunctionFlux1Phase
    boundary = 'outlet:in'
    connection_index = 2
    junction = outlet_plenum
    equation = mass
  []
  [outlet_out_m_dot]
    type = ADFlowBoundaryFlux1Phase
    boundary = 'outlet_bc'
    equation = mass
  []

  [net_mass_flow_rate_domain]
    type = LinearCombinationPostprocessor
    pp_names = 'inlet_in_m_dot outlet_out_m_dot'
    pp_coefs = '1 -1'
  []
  [net_mass_flow_rate_volume_junction]
    type = LinearCombinationPostprocessor
    pp_names = 'inlet_out_m_dot channel1_in_m_dot channel2_in_m_dot'
    pp_coefs = '1 -1 -1'
  []
[]

[Preconditioning]
  [smp]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  scheme = bdf2
  start_time = 0
  end_time = 10000
  [TimeStepper]
    type = IterationAdaptiveDT
    dt = 0.01
    optimal_iterations = 8
    iteration_window = 2
  []
  timestep_tolerance = 1e-6
  abort_on_solve_fail = true

  line_search = none
  nl_rel_tol = 1e-8
  nl_abs_tol = 2e-8
  nl_max_its = 25
  l_tol = 1e-3
  l_max_its = 5
  petsc_options = '-snes_converged_reason'
  petsc_options_iname = '-pc_type'
  petsc_options_value = ' lu     '
[]

[Outputs]
  [out]
    type = CSV
    execute_on = 'FINAL'
    show = 'net_mass_flow_rate_domain net_mass_flow_rate_volume_junction'
  []
[]

(modules/thermal_hydraulics/test/tests/misc/mesh_only/test.i)

[GlobalParams]
  initial_T = 300
  initial_p = 1e5
  initial_vel = 0
  initial_vel_x = 0
  initial_vel_y = 0
  initial_vel_z = 0
  gravity_vector = '0 0 0'
  scaling_factor_1phase = '1.e0 1.e-4 1.e-6'

  closures = simple_closures
[]

[FluidProperties]
  [eos]
    type = StiffenedGasFluidProperties
    gamma = 2.35
    q = -1167e3
    q_prime = 0
    p_inf = 1.e9
    cv = 1816
  []
[]

[Closures]
  [simple_closures]
    type = Closures1PhaseSimple
  []
[]

[SolidProperties]
  [hs_mat]
    type = ThermalFunctionSolidProperties
     rho = 1
     cp = 1
     k = 1
  []
[]

[Components]
  [pipe1]
    type = FlowChannel1Phase
    fp = eos
    position = '0 0 0'
    orientation = '1 0 0'
    A = 1.
    D_h = 1.12837916709551
    f = 0
    length = 1
    n_elems = 10
  []

  [hs1]
    type = HeatStructurePlate
    fp = eos
    position = '0 0 0'
    orientation = '1 0 0'
    n_elems = 10
    length = 1
    depth = 0.1
    names = 'blk'
    solid_properties = 'hs_mat'
    solid_properties_T_ref = '300'
    n_part_elems = 1
    widths = '0.1'
  []

  [pipe2]
    type = FlowChannel1Phase
    fp = eos
    position = '0 0 0'
    orientation = '0 1 0'
    A = 1.
    D_h = 1.12837916709551
    f = 0
    length = 1
    n_elems = 10
  []

  [hs2]
    type = HeatStructurePlate
    fp = eos
    position = '0 0 0'
    orientation = '0 1 0'
    n_elems = 10
    length = 1
    depth = 0.1
    names = 'blk'
    solid_properties = 'hs_mat'
    solid_properties_T_ref = '300'
    n_part_elems = 1
    widths = '0.1'
  []

  [pipe3]
    type = FlowChannel1Phase
    fp = eos
    position = '0 0 0'
    orientation = '0 0 1'
    A = 1.
    D_h = 1.12837916709551
    f = 0
    length = 1
    n_elems = 10
  []

  [hs3]
    type = HeatStructurePlate
    fp = eos
    position = '0 0 0'
    orientation = '0 0 1'
    n_elems = 10
    length = 1
    depth = 0.1
    names = 'blk'
    solid_properties = 'hs_mat'
    solid_properties_T_ref = '300'
    n_part_elems = 1
    widths = '0.1'
  []

  [junction]
    type = VolumeJunction1Phase
    connections = 'pipe1:in pipe2:in pipe3:in'
    position = '0 0 0'
    volume = 1e-5
    use_scalar_variables = false
  []

  [in1]
    type = SolidWall
    input = 'pipe1:out'
  []
  [in2]
    type = SolidWall
    input = 'pipe2:out'
  []
  [in3]
    type = SolidWall
    input = 'pipe3:out'
  []
[]

[Preconditioning]
  [pc]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  scheme = 'bdf2'

  start_time = 0
  dt = 1e-5
  num_steps = 1
  abort_on_solve_fail = true
[]

(modules/thermal_hydraulics/test/tests/misc/restart_1phase/test.i)

[GlobalParams]
  gravity_vector = '0 0 0'

  closures = simple_closures
[]

[FluidProperties]
  [eos]
    type = StiffenedGasFluidProperties
    gamma = 2.35
    q = -1167e3
    q_prime = 0
    p_inf = 1.e9
    cv = 1816
  []
[]

[Closures]
  [simple_closures]
    type = Closures1PhaseSimple
  []
[]

[SolidProperties]
  [mat1]
    type = ThermalFunctionSolidProperties
    k = 16
    cp = 356.
    rho = 6.551400E+03
  []
[]

[Functions]
  [Ts_init]
    type = ParsedFunction
    expression = '2*sin(x*pi)+507'
  []
[]

[Components]
  [pipe1]
    type = FlowChannel1Phase
    fp = eos
    # geometry
    position = '0 0 0'
    orientation = '1 0 0'
    length = 1
    n_elems = 5
    A = 1.907720E-04
    D_h = 1.698566E-02
    f = 0.1
  []

  [jct1]
    type = VolumeJunction1Phase
    connections = 'pipe1:out pipe2:in'
    position = '1 0 0'
    volume = 1e-5
    use_scalar_variables = false
  []

  [pipe2]
    type = FlowChannel1Phase
    fp = eos
    # geometry
    position = '1 0 0'
    orientation = '1 0 0'
    length = 1
    n_elems = 5
    A = 1.907720E-04
    D_h = 1.698566E-02
    f = 0.1
  []

  [jct2]
    type = VolumeJunction1Phase
    connections = 'pipe2:out pipe3:in'
    position = '2 0 0'
    volume = 1e-5
    use_scalar_variables = false
  []

  [pipe3]
    type = FlowChannel1Phase
    fp = eos
    # geometry
    position = '2 0 0'
    orientation = '1 0 0'
    length = 1
    n_elems = 5
    A = 1.907720E-04
    D_h = 1.698566E-02
    f = 0.1
  []

  [hs]
    type = HeatStructureCylindrical
    position = '1 0.01 0'
    orientation = '1 0 0'
    length = 1
    n_elems = 5
    names = '0'
    n_part_elems = 1
    solid_properties = 'mat1'
    solid_properties_T_ref = '300'
    widths = 0.1
  []

  [temp_outside]
    type = HSBoundarySpecifiedTemperature
    hs = hs
    boundary = hs:outer
    T = Ts_init
  []

  [inlet]
    type = InletVelocityTemperature1Phase
    input = 'pipe1:in'
    T = 507
    vel = 1
  []
  [outlet]
    type = Outlet1Phase
    input = 'pipe3:out'
    p = 6e6
  []

  [hx3ext]
    type = HeatTransferFromExternalAppTemperature1Phase
    flow_channel = pipe3
    P_hf = 0.0449254
    Hw = 100000
  []
[]

[Preconditioning]
  [SMP_PJFNK]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  scheme = 'bdf2'

  dt = 0.01
  num_steps = 5
  abort_on_solve_fail = true

  solve_type = 'newton'
  line_search = 'basic'
  nl_rel_tol = 1e-8
  nl_abs_tol = 1e-8
  nl_max_its = 10

  l_tol = 1e-3
  l_max_its = 100

  automatic_scaling = true

  petsc_options_iname = '-pc_type'
  petsc_options_value = ' lu'
[]

[Outputs]
  exodus = true
  velocity_as_vector = false
[]

(modules/thermal_hydraulics/test/tests/components/volume_junction_1phase/phy.form_loss.i)

# This test measures the pressure drop across the volume junction with K=1.

A = 0.1

[GlobalParams]
  gravity_vector = '0 0 0'

  scaling_factor_1phase = '1 1 1e-5'
  scaling_factor_rhoV = 1
  scaling_factor_rhouV = 1
  scaling_factor_rhovV = 1
  scaling_factor_rhowV = 1
  scaling_factor_rhoEV = 1e-5

  initial_T = 300
  initial_p = 1e5
  initial_vel = 1

  n_elems = 20
  length = 1

  f = 0

  fp = fp
  closures = simple_closures
[]

[FluidProperties]
  [fp]
    type = StiffenedGasFluidProperties
    gamma = 1.4
    cv = 725
    q = 0
    q_prime = 0
    p_inf = 0
  []
[]

[Closures]
  [simple_closures]
    type = Closures1PhaseSimple
  []
[]

[Functions]
  [K_fn]
    type = TimeRampFunction
    initial_value = 0
    initial_time = 2
    ramp_duration = 5
    final_value = 1
  []
[]

[Components]
  [pipe1]
    type = FlowChannel1Phase
    position = '0 0 0'
    orientation = '1 0 0'
    A = ${A}
  []

  [pipe2]
    type = FlowChannel1Phase
    position = '1 0 0'
    orientation = '1 0 0'
    A = ${A}
    initial_p = 1e5
  []

  [junction]
    type = VolumeJunction1Phase
    connections = 'pipe1:out pipe2:in'

    position = '1 0 0'
    volume = 0.005
    initial_p = 1e5
    initial_vel_x = 1
    initial_vel_y = 0
    initial_vel_z = 0
    use_scalar_variables = false
  []

  [pipe1_in]
    type = InletVelocityTemperature1Phase
    input = 'pipe1:in'
    vel = 1
    T = 300
  []

  [pipe2_out]
    type = Outlet1Phase
    input = 'pipe2:out'
    p = 1e5
  []
[]

[ControlLogic]
  active = ''
  [K_crtl]
    type = TimeFunctionComponentControl
    component = junction
    parameter = K
    function = K_fn
  []
[]

[Postprocessors]
  [pJ_in]
    type = SideAverageValue
    variable = p
    boundary = pipe1:out
  []

  [pJ_out]
    type = SideAverageValue
    variable = p
    boundary = pipe2:in
  []

  [dpJ]
    type = DifferencePostprocessor
    value1 = pJ_in
    value2 = pJ_out
  []
[]

[Preconditioning]
  [pc]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  scheme = 'bdf2'

  start_time = 0
  end_time = 20
  dt = 0.5
  abort_on_solve_fail = true

  solve_type = 'NEWTON'
  nl_rel_tol = 0
  nl_abs_tol = 1e-8
  nl_max_its = 15

  l_tol = 1e-3
  l_max_its = 10

  petsc_options_iname = '-pc_type'
  petsc_options_value = 'lu'
[]

[Outputs]
  csv = true
  execute_on = 'final'
  show = 'dpJ'
[]

(modules/thermal_hydraulics/test/tests/components/volume_junction_1phase/equal_area_with_junction.i)

# Tests a junction between 2 flow channels of equal area and orientation. A
# sinusoidal density shape is advected to the right and should not be affected
# by the junction; the solution should be identical to the equivalent
# no-junction solution.

[GlobalParams]
  gravity_vector = '0 0 0'

  initial_p = 1e5
  initial_vel = 1

  A = 25

  f = 0

  fp = fp

  scaling_factor_1phase = '0.04 0.04 0.04e-5'

  closures = simple_closures
[]

[FluidProperties]
  [fp]
    type = StiffenedGasFluidProperties
    gamma = 1.4
    cv = 725
    p_inf = 0
    q = 0
    q_prime = 0
  []
[]

[Closures]
  [simple_closures]
    type = Closures1PhaseSimple
  []
[]

[Functions]
  [T0]
    type = CosineHumpFunction
    axis = x
    hump_center_position = 1
    hump_width = 0.5
    hump_begin_value = 250
    hump_center_value = 300
  []
[]

[Components]
  [inlet]
    type = InletStagnationPressureTemperature1Phase
    input = 'pipe1:in'
    # Stagnation property with p = 1e5 Pa, T = 250 K, vel = 1 m/s
    p0 = 100000.68965687
    T0 = 250.00049261084
  []

  [pipe1]
    type = FlowChannel1Phase

    position = '0 0 0'
    orientation = '1 0 0'
    length = 1

    initial_T = T0

    n_elems = 25
  []

  [junction]
    type = VolumeJunction1Phase
    connections = 'pipe1:out pipe2:in'

    # NOTE: volume parameters are added via command-line arguments by tests file.
    position = '1.02 0 0'

    initial_T = T0
    initial_vel_x = 1
    initial_vel_y = 0
    initial_vel_z = 0

    scaling_factor_rhoV  = 1
    scaling_factor_rhouV = 1
    scaling_factor_rhovV = 1
    scaling_factor_rhowV = 1
    scaling_factor_rhoEV = 1e-5

    use_scalar_variables = false
  []

  [pipe2]
    type = FlowChannel1Phase

    position = '1.04 0 0'
    orientation = '1 0 0'
    length = 0.96

    initial_T = T0

    n_elems = 24
  []

  [outlet]
    type = Outlet1Phase
    input = 'pipe2:out'
    p = 1e5
  []
[]

[Preconditioning]
  [pc]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient

  scheme = 'bdf2'
  start_time = 0
  dt = 0.01
  num_steps = 5
  abort_on_solve_fail = true

  solve_type = 'PJFNK'
  line_search = 'basic'
  nl_rel_tol = 0
  nl_abs_tol = 1e-6
  nl_max_its = 10

  l_tol = 1e-3
  l_max_its = 10

  petsc_options_iname = '-pc_type'
  petsc_options_value = 'lu'

  [Quadrature]
    type = GAUSS
    order = SECOND
  []
[]

[Postprocessors]
  [junction_rho]
    type = ElementAverageValue
    variable = rhoV
    block = 'junction'
    execute_on = 'initial timestep_end'
  []
  [junction_rhou]
    type = ElementAverageValue
    variable = rhouV
    block = 'junction'
    execute_on = 'initial timestep_end'
  []
  [junction_rhoE]
    type = ElementAverageValue
    variable = rhoEV
    block = 'junction'
    execute_on = 'initial timestep_end'
  []
[]

[Outputs]
  [out]
    type = CSV
    execute_scalars_on = 'none'
    execute_on = 'initial timestep_end'
  []
[]

(modules/thermal_hydraulics/test/tests/problems/brayton_cycle/recuperated_brayton_cycle.i)

# This input file models an open, recuperated Brayton cycle with a PID
# controlled start up using a coupled motor.
#
# Heat is supplied to the system by a volumetric heat source, and a second heat
# source is used to model a recuperator. The recuperator transfers heat from the
# turbine exhaust gas to the compressor outlet gas.
#
# Initially the fluid and heat structures are at rest at ambient conditions,
# and the shaft speed is zero.
# The transient is controlled as follows:
#   * 0   - 2000 s: Motor increases shaft speed to approx. 85,000 RPM by PID control
#   * 1000 - 8600 s: Power in main heat source increases from 0 - 104 kW
#   * 2000 - 200000 s: Torque supplied by turbine increases to steady state level
#                      as working fluid temperature increases. Torque supplied by
#                      the motor is ramped down to 0 N-m transitioning shaft control
#                      to the turbine at its rated speed of 96,000 RPM.


I_motor = 1.0

I_generator = 1.0
generator_torque_per_shaft_speed = -0.00025

motor_ramp_up_duration = 3605
motor_ramp_down_duration = 1800
post_motor_time = 2160000
t1 = ${motor_ramp_up_duration}
t2 = ${fparse t1 + motor_ramp_down_duration}
t3 = ${fparse t2 + post_motor_time}

D1 = 0.15
D2 = ${D1}
D3 = ${D1}
D4 = ${D1}
D5 = ${D1}
D6 = ${D1}
D7 = ${D1}
D8 = ${D1}

A1 = ${fparse 0.25 * pi * D1^2}
A2 = ${fparse 0.25 * pi * D2^2}
A3 = ${fparse 0.25 * pi * D3^2}
A4 = ${fparse 0.25 * pi * D4^2}
A5 = ${fparse 0.25 * pi * D5^2}
A6 = ${fparse 0.25 * pi * D6^2}
A7 = ${fparse 0.25 * pi * D7^2}
A8 = ${fparse 0.25 * pi * D8^2}

recuperator_width = 0.15

L1 = 5.0
L2 = ${L1}
L3 = ${fparse 2 * L1}
L4 = ${fparse 2 * L1}
L5 = ${L1}
L6 = ${L1}
L7 = ${fparse L1 + recuperator_width}
L8 = ${L1}

x1 = 0.0
x2 = ${fparse x1 + L1}
x3 = ${fparse x2 + L2}
x4 = ${x3}
x5 = ${fparse x4 - L4}
x6 = ${x5}
x7 = ${fparse x6 + L6}
x8 = ${fparse x7 + L7}

y1 = 0
y2 = ${y1}
y3 = ${y2}
y4 = ${fparse y3 - L3}
y5 = ${y4}
y6 = ${fparse y5 + L5}
y7 = ${y6}
y8 = ${y7}

x1_out = ${fparse x1 + L1 - 0.001}
x2_in = ${fparse x2 + 0.001}
y5_in = ${fparse y5 + 0.001}
x6_out = ${fparse x6 + L6 - 0.001}
x7_in = ${fparse x7 + 0.001}
y8_in = ${fparse y8 + 0.001}
y8_out = ${fparse y8 + L8 - 0.001}
hot_leg_in = ${y8_in}
hot_leg_out = ${y8_out}
cold_leg_in = ${fparse y3 - 0.001}
cold_leg_out = ${fparse y3 - (L3/2) - 0.001}

n_elems1 = 5
n_elems2 = ${n_elems1}
n_elems3 = ${fparse 2 * n_elems1}
n_elems4 = ${fparse 2 * n_elems1}
n_elems5 = ${n_elems1}
n_elems6 = ${n_elems1}
n_elems7 = ${n_elems1}
n_elems8 = ${n_elems1}

A_ref_comp = ${fparse 0.5 * (A1 + A2)}
V_comp = ${fparse A_ref_comp * 1.0}
I_comp = 1.0

A_ref_turb = ${fparse 0.5 * (A4 + A5)}
V_turb = ${fparse A_ref_turb * 1.0}
I_turb = 1.0

c0_rated_comp = 351.6925137
rho0_rated_comp = 1.146881112

rated_mfr = 0.25

speed_rated_rpm = 96000
speed_rated = ${fparse speed_rated_rpm * 2 * pi / 60.0}

speed_initial = 0

eff_comp = 0.79
eff_turb = 0.843

T_ambient = 300
p_ambient = 1e5

hs_power = 105750
[GlobalParams]
  gravity_vector = '0 0 0'

  initial_p = ${p_ambient}
  initial_T = ${T_ambient}
  initial_vel = 0
  initial_vel_x = 0
  initial_vel_y = 0
  initial_vel_z = 0

  fp = fp_air
  closures = closures
  f = 0

  scaling_factor_1phase = '1 1 1e-5'
  scaling_factor_rhoV = 1
  scaling_factor_rhouV = 1e-2
  scaling_factor_rhovV = 1e-2
  scaling_factor_rhowV = 1e-2
  scaling_factor_rhoEV = 1e-5
  scaling_factor_temperature = 1e-2
  rdg_slope_reconstruction = none
[]

[FluidProperties]
  [fp_air]
    type = IdealGasFluidProperties
    emit_on_nan = none
  []
[]

[SolidProperties]
  [steel]
    type = ThermalFunctionSolidProperties
    rho = 8050
    k = 45
    cp = 466
  []
[]

[Closures]
  [closures]
    type = Closures1PhaseSimple
  []
[]

[Functions]

  ##########################
  # Motor
  ##########################


  # Functions for control logic that determines when to shut off the PID system
  [is_tripped_fn]
    type = ParsedFunction
    symbol_names = 'motor_torque turbine_torque'
    symbol_values = 'motor_torque turbine_torque'
    expression = 'turbine_torque > motor_torque'
  []
  [PID_tripped_constant_value]
    type = ConstantFunction
    value = 1
  []
  [PID_tripped_status_fn]
    type = ParsedFunction
    symbol_values = 'PID_trip_status'
    symbol_names = 'PID_trip_status'
    expression = 'PID_trip_status'
  []
  [time_fn]
    type = ParsedFunction
    expression = t
  []

  # Shutdown function which ramps down the motor once told by the control logic
  [motor_torque_fn_shutdown]
    type = ParsedFunction
    symbol_values = 'PID_trip_status time_trip'
    symbol_names = 'PID_trip_status time_trip'
    expression = 'if(PID_trip_status = 1, max(2.4 - (2.4 * ((t - time_trip) / 35000)),0.0), 1)'
  []

  # Generates motor power curve
  [motor_power_fn]
    type = ParsedFunction
    expression = 'torque * speed'
    symbol_names = 'torque speed'
    symbol_values = 'motor_torque shaft:omega'
  []

  ##########################
  # Generator
  ##########################

  # Generates generator torque curve
  [generator_torque_fn]
    type = ParsedFunction
    expression = 'slope * t'
    symbol_names = 'slope'
    symbol_values = '${generator_torque_per_shaft_speed}'
  []
  # Generates generator power curve
  [generator_power_fn]
    type = ParsedFunction
    expression = 'torque * speed'
    symbol_names = 'torque speed'
    symbol_values = 'generator_torque shaft:omega'
  []

  ##########################
  # Reactor
  ##########################

  # Ramps up reactor power when activated by control logic
  [power_fn]
    type = PiecewiseLinear
    x = '0 1000 8600'
    y = '0 0 ${hs_power}'
  []

  ##########################
  # Compressor
  ##########################

  # compressor pressure ratios
  [rp_comp1]
    type = PiecewiseLinear
    data_file = 'rp_comp1.csv'
    x_index_in_file = 0
    y_index_in_file = 1
    format = columns
    extrap = true
  []
  [rp_comp2]
    type = PiecewiseLinear
    data_file = 'rp_comp2.csv'
    x_index_in_file = 0
    y_index_in_file = 1
    format = columns
    extrap = true
  []
  [rp_comp3]
    type = PiecewiseLinear
    data_file = 'rp_comp3.csv'
    x_index_in_file = 0
    y_index_in_file = 1
    format = columns
    extrap = true
  []
  [rp_comp4]
    type = PiecewiseLinear
    data_file = 'rp_comp4.csv'
    x_index_in_file = 0
    y_index_in_file = 1
    format = columns
    extrap = true
  []
  [rp_comp5]
    type = PiecewiseLinear
    data_file = 'rp_comp5.csv'
    x_index_in_file = 0
    y_index_in_file = 1
    format = columns
    extrap = true
  []

  # compressor efficiencies
  [eff_comp1]
    type = ConstantFunction
    value = ${eff_comp}
  []
  [eff_comp2]
    type = ConstantFunction
    value = ${eff_comp}
  []
  [eff_comp3]
    type = ConstantFunction
    value = ${eff_comp}
  []
  [eff_comp4]
    type = ConstantFunction
    value = ${eff_comp}
  []
  [eff_comp5]
    type = ConstantFunction
    value = ${eff_comp}
  []

  ##########################
  # Turbine
  ##########################

  # turbine pressure ratios
  [rp_turb0]
    type = ConstantFunction
    value = 1
  []
  [rp_turb1]
    type = PiecewiseLinear
    data_file = 'rp_turb1.csv'
    x_index_in_file = 0
    y_index_in_file = 1
    format = columns
    extrap = true
  []
  [rp_turb2]
    type = PiecewiseLinear
    data_file = 'rp_turb2.csv'
    x_index_in_file = 0
    y_index_in_file = 1
    format = columns
    extrap = true
  []
  [rp_turb3]
    type = PiecewiseLinear
    data_file = 'rp_turb3.csv'
    x_index_in_file = 0
    y_index_in_file = 1
    format = columns
    extrap = true
  []
  [rp_turb4]
    type = PiecewiseLinear
    data_file = 'rp_turb4.csv'
    x_index_in_file = 0
    y_index_in_file = 1
    format = columns
    extrap = true
  []
  [rp_turb5]
    type = PiecewiseLinear
    data_file = 'rp_turb5.csv'
    x_index_in_file = 0
    y_index_in_file = 1
    format = columns
    extrap = true
  []

  # turbine efficiency
  [eff_turb1]
    type = ConstantFunction
    value = ${eff_turb}
  []
  [eff_turb2]
    type = ConstantFunction
    value = ${eff_turb}
  []
  [eff_turb3]
    type = ConstantFunction
    value = ${eff_turb}
  []
  [eff_turb4]
    type = ConstantFunction
    value = ${eff_turb}
  []
  [eff_turb5]
    type = ConstantFunction
    value = ${eff_turb}
  []
[]

[Components]

  # system inlet pulling air from the open atmosphere
  [inlet]
    type = InletStagnationPressureTemperature1Phase
    input = 'pipe1:in'
    p0 = ${p_ambient}
    T0 = ${T_ambient}
  []

  # Inlet pipe
  [pipe1]
    type = FlowChannel1Phase
    position = '${x1} ${y1} 0'
    orientation = '1 0 0'
    length = ${L1}
    n_elems = ${n_elems1}
    A = ${A1}
  []

  # Compressor as defined in MAGNET PCU document (Guillen 2020)
  [compressor]
    type = ShaftConnectedCompressor1Phase
    position = '${x2} ${y2} 0'
    inlet = 'pipe1:out'
    outlet = 'pipe2:in'
    A_ref = ${A_ref_comp}
    volume = ${V_comp}

    omega_rated = ${speed_rated}
    mdot_rated = ${rated_mfr}
    c0_rated = ${c0_rated_comp}
    rho0_rated = ${rho0_rated_comp}

    # Determines which compression ratio curve and efficiency curve to use depending on ratio of speed/rated_speed
    speeds = '0.5208 0.6250 0.7292 0.8333 0.9375'
    Rp_functions = 'rp_comp1 rp_comp2 rp_comp3 rp_comp4 rp_comp5'
    eff_functions = 'eff_comp1 eff_comp2 eff_comp3 eff_comp4 eff_comp5'

    min_pressure_ratio = 1.0

    speed_cr_I = 0
    inertia_const = ${I_comp}
    inertia_coeff = '${I_comp} 0 0 0'

    # assume no shaft friction
    speed_cr_fr = 0
    tau_fr_const = 0
    tau_fr_coeff = '0 0 0 0'

    use_scalar_variables = false
  []

  # Outlet pipe from the compressor
  [pipe2]
    type = FlowChannel1Phase
    position = '${x2} ${y2} 0'
    orientation = '1 0 0'
    length = ${L2}
    n_elems = ${n_elems2}
    A = ${A2}
  []

  # 90 degree connection between pipe 2 and 3
  [junction2_cold_leg]
    type = VolumeJunction1Phase
    connections = 'pipe2:out cold_leg:in'
    position = '${x3} ${y3} 0'
    volume = ${fparse A2*0.1}
    use_scalar_variables = false
  []

  # Cold leg of the recuperator
  [cold_leg]
    type = FlowChannel1Phase
    position = '${x3} ${y3} 0'
    orientation = '0 -1 0'
    length = ${fparse L3/2}
    n_elems = ${fparse n_elems3/2}
    A = ${A3}
  []

  # Recuperator which transfers heat from exhaust gas to reactor inlet gas to improve thermal efficency
  [recuperator]
    type = HeatStructureCylindrical
    orientation = '0 -1 0'
    position = '${x3} ${y3} 0'
    length = ${fparse L3/2}
    widths = ${recuperator_width}
    n_elems = ${fparse n_elems3/2}
    n_part_elems = 2
    names = recuperator
    solid_properties = steel
    solid_properties_T_ref = '300'
    inner_radius = ${D1}
  []
  # heat transfer from recuperator to cold leg
  [heat_transfer_cold_leg]
    type = HeatTransferFromHeatStructure1Phase
    flow_channel = cold_leg
    hs = recuperator
    hs_side = OUTER
    Hw = 10000
  []
  # heat transfer from hot leg to recuperator
  [heat_transfer_hot_leg]
    type = HeatTransferFromHeatStructure1Phase
    flow_channel = hot_leg
    hs = recuperator
    hs_side = INNER
    Hw = 10000
  []

  [junction_cold_leg_3]
    type = JunctionOneToOne1Phase
    connections = 'cold_leg:out pipe3:in'
  []
  [pipe3]
    type = FlowChannel1Phase
    position = '${x3} ${fparse y3 - (L3/2)} 0'
    orientation = '0 -1 0'
    length = ${fparse L3/2}
    n_elems = ${fparse n_elems3/2}
    A = ${A3}
  []
  # 90 degree connection between pipe 3 and 4
  [junction3_4]
    type = VolumeJunction1Phase
    connections = 'pipe3:out pipe4:in'
    position = '${x4} ${y4} 0'
    volume = ${fparse A3*0.1}
    use_scalar_variables = false
  []

  # Pipe through the "reactor core"
  [pipe4]
    type = FlowChannel1Phase
    position = '${x4} ${y4} 0'
    orientation = '-1 0 0'
    length = ${L4}
    n_elems = ${n_elems4}
    A = ${A4}
  []

  # "Reactor Core" and it's associated heat transfer to pipe 4
  [reactor]
    type = HeatStructureCylindrical
    orientation = '-1 0 0'
    position = '${x4} ${y4} 0'
    length = ${L4}
    widths = 0.15
    n_elems = ${n_elems4}
    n_part_elems = 2
    names = core
    solid_properties = steel
    solid_properties_T_ref = '300'
  []
  [total_power]
    type = TotalPower
    power = 0
  []
  [heat_generation]
    type = HeatSourceFromTotalPower
    power = total_power
    hs = reactor
    regions = core
  []
  [heat_transfer]
    type = HeatTransferFromHeatStructure1Phase
    flow_channel = pipe4
    hs = reactor
    hs_side = OUTER
    Hw = 10000
  []

  # 90 degree connection between pipe 4 and 5
  [junction4_5]
    type = VolumeJunction1Phase
    connections = 'pipe4:out pipe5:in'
    position = '${x5} ${y5} 0'
    volume = ${fparse A4*0.1}
    use_scalar_variables = false
  []

  # Pipe carrying hot gas back to the PCU
  [pipe5]
    type = FlowChannel1Phase
    position = '${x5} ${y5} 0'
    orientation = '0 1 0'
    length = ${L5}
    n_elems = ${n_elems5}
    A = ${A5}
  []

  # 90 degree connection between pipe 5 and 6
  [junction5_6]
    type = VolumeJunction1Phase
    connections = 'pipe5:out pipe6:in'
    position = '${x6} ${y6} 0'
    volume = ${fparse A5*0.1}
    use_scalar_variables = false
  []

  # Inlet pipe to the turbine
  [pipe6]
    type = FlowChannel1Phase
    position = '${x6} ${y6} 0'
    orientation = '1 0 0'
    length = ${L6}
    n_elems = ${n_elems6}
    A = ${A6}
  []

  # Turbine as defined in MAGNET PCU document (Guillen 2020) and (Wright 2006)
  [turbine]
    type = ShaftConnectedCompressor1Phase
    position = '${x7} ${y7} 0'
    inlet = 'pipe6:out'
    outlet = 'pipe7:in'
    A_ref = ${A_ref_turb}
    volume = ${V_turb}

    # A turbine is treated as an "inverse" compressor, this value determines if component is to be treated as turbine or compressor
    # If treat_as_turbine is omitted, code automatically assumes it is a compressor
    treat_as_turbine = true

    omega_rated = ${speed_rated}
    mdot_rated = ${rated_mfr}
    c0_rated = ${c0_rated_comp}
    rho0_rated = ${rho0_rated_comp}

    # Determines which compression ratio curve and efficiency curve to use depending on ratio of speed/rated_speed
    speeds = '0 0.5208 0.6250 0.7292 0.8333 0.9375'
    Rp_functions = 'rp_turb0 rp_turb1 rp_turb2 rp_turb3 rp_turb4 rp_turb5'
    eff_functions = 'eff_turb1 eff_turb1 eff_turb2 eff_turb3 eff_turb4 eff_turb5'

    min_pressure_ratio = 1.0

    speed_cr_I = 0
    inertia_const = ${I_turb}
    inertia_coeff = '${I_turb} 0 0 0'

    # assume no shaft friction
    speed_cr_fr = 0
    tau_fr_const = 0
    tau_fr_coeff = '0 0 0 0'

    use_scalar_variables = false
  []

  # Outlet pipe from turbine
  [pipe7]
    type = FlowChannel1Phase
    position = '${x7} ${y7} 0'
    orientation = '1 0 0'
    length = ${L7}
    n_elems = ${n_elems7}
    A = ${A7}
  []

  # 90 degree connection between pipe 7 and 8
  [junction7_hot_leg]
    type = VolumeJunction1Phase
    connections = 'pipe7:out hot_leg:in'
    position = '${x8} ${y8} 0'
    volume = ${fparse A7*0.1}
    use_scalar_variables = false
  []

  # Hot leg of the recuperator
  [hot_leg]
    type = FlowChannel1Phase
    position = '${x8} ${y8} 0'
    orientation = '0 1 0'
    length = ${L8}
    n_elems = ${n_elems8}
    A = ${A8}
  []

  # System outlet dumping exhaust gas to the atmosphere
  [outlet]
    type = Outlet1Phase
    input = 'hot_leg:out'
    p = ${p_ambient}
  []

  # Roatating shaft connecting motor, compressor, turbine, and generator
  [shaft]
    type = Shaft
    connected_components = 'motor compressor turbine generator'
    initial_speed = ${speed_initial}
  []

  # 3-Phase electircal motor used for system start-up, controlled by PID
  [motor]
    type = ShaftConnectedMotor
    inertia = ${I_motor}
    torque = 0 # controlled
  []

  # Electric generator supplying power to the grid
  [generator]
    type = ShaftConnectedMotor
    inertia = ${I_generator}
    torque = generator_torque_fn
  []
[]


# Control logics which govern startup of the motor, startup of the "reactor core", and shutdown of the motor
[ControlLogic]

  # Sets desired shaft speed to be reached by motor NOTE: SHOULD BE SET LOWER THAN RATED TURBINE RPM
  [set_point]
    type = GetFunctionValueControl
    function = ${fparse speed_rated_rpm - 9000}
  []

  # PID with gains determined by iterative process NOTE: Gain values are system specific
  [initial_motor_PID]
    type = PIDControl
    set_point = set_point:value
    input = shaft_RPM
    initial_value = 0
    K_p = 0.0011
    K_i = 0.00000004
    K_d = 0
  []

  # Determines when the PID system should be running and when it should begin the shutdown cycle. If needed: PID output, else: shutdown function
  [logic]
    type = ParsedFunctionControl
    function = 'if(motor+0.5 > turb, PID, shutdown_fn)'
    symbol_names = 'motor turb PID shutdown_fn'
    symbol_values = 'motor_torque turbine_torque initial_motor_PID:output motor_torque_fn_shutdown'
  []

  # Takes the output generated in [logic] and applies it to the motor torque
  [motor_PID]
    type = SetComponentRealValueControl
    component = motor
    parameter = torque
    value = logic:value
  []
  # Determines when to turn on heat source
  [power_logic]
    type = ParsedFunctionControl
    function = 'power_fn'
    symbol_names = 'power_fn'
    symbol_values = 'power_fn'
  []
  # Applies heat source to the total_power block
  [power_applied]
    type = SetComponentRealValueControl
    component = total_power
    parameter = power
    value = power_logic:value
  []
[]

[Controls]

  # Enables set_PID_tripped
  [PID_trip_status]
    type = ConditionalFunctionEnableControl
    conditional_function = is_tripped_fn
    enable_objects = 'AuxScalarKernels::PID_trip_status_aux'
    execute_on = 'TIMESTEP_END'
  []

  # Enables set_time_PID
  [time_PID]
    type = ConditionalFunctionEnableControl
    conditional_function = PID_tripped_status_fn
    disable_objects = 'AuxScalarKernels::time_trip_aux'
    execute_on = 'TIMESTEP_END'
  []
[]

[AuxVariables]

  # Creates a variable that will later be set to the time when tau_turbine > tau_motor
  [time_trip]
    order = FIRST
    family = SCALAR
  []

  # Creates variable which indicates if tau_turbine > tau_motor....... If tau_motor > tau_turbine, 0, else 1
  [PID_trip_status]
    order = FIRST
    family = SCALAR
    initial_condition = 0
  []
[]

[AuxScalarKernels]

  # Creates variable from time_fn which indicates when tau_turbine > tau_motor
  [time_trip_aux]
    type = FunctionScalarAux
    function = time_fn
    variable = time_trip
    execute_on = 'TIMESTEP_END'
  []

  # Overwrites variable PID_trip_status to the value from PID_tripped_constant_value (changes 0 to 1)
  [PID_trip_status_aux]
    type = FunctionScalarAux
    function = PID_tripped_constant_value
    variable = PID_trip_status
    execute_on = 'TIMESTEP_END'
    enable = false
  []
[]


[Postprocessors]

  # Indicates when tau_turbine > tau_motor
  [trip_time]
    type = ScalarVariable
    variable = time_trip
    execute_on = 'TIMESTEP_END'
  []

  ##########################
  # Motor
  ##########################

  [motor_torque]
    type = RealComponentParameterValuePostprocessor
    component = motor
    parameter = torque
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [motor_power]
    type = FunctionValuePostprocessor
    function = motor_power_fn
    execute_on = 'INITIAL TIMESTEP_END'
  []

  ##########################
  # generator
  ##########################

  [generator_torque]
    type = ShaftConnectedComponentPostprocessor
    quantity = torque
    shaft_connected_component_uo = generator:shaftconnected_uo
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [generator_power]
    type = FunctionValuePostprocessor
    function = generator_power_fn
    execute_on = 'INITIAL TIMESTEP_END'
  []

  ##########################
  # Shaft
  ##########################

  # Speed in rad/s
  [shaft_speed]
    type = ScalarVariable
    variable = 'shaft:omega'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  # speed in RPM
  [shaft_RPM]
    type = ParsedPostprocessor
    pp_names = 'shaft_speed'
    expression = '(shaft_speed * 60) /( 2 * ${fparse pi})'
    execute_on = 'INITIAL TIMESTEP_END'
  []

  ##########################
  # Compressor
  ##########################
  [comp_dissipation_torque]
    type = ElementAverageValue
    variable = dissipation_torque
    block = 'compressor'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [comp_isentropic_torque]
    type = ElementAverageValue
    variable = isentropic_torque
    block = 'compressor'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [comp_friction_torque]
    type = ElementAverageValue
    variable = friction_torque
    block = 'compressor'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [compressor_torque]
    type = ParsedPostprocessor
    pp_names = 'comp_dissipation_torque comp_isentropic_torque comp_friction_torque'
    expression = 'comp_dissipation_torque + comp_isentropic_torque + comp_friction_torque'
  []
  [p_in_comp]
    type = PointValue
    variable = p
    point = '${x1_out} ${y1} 0'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [p_out_comp]
    type = PointValue
    variable = p
    point = '${x2_in} ${y2} 0'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [p_ratio_comp]
    type = ParsedPostprocessor
    pp_names = 'p_in_comp p_out_comp'
    expression = 'p_out_comp / p_in_comp'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [T_in_comp]
    type = PointValue
    variable = T
    point = '${x1_out} ${y1} 0'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [T_out_comp]
    type = PointValue
    variable = T
    point = '${x2_in} ${y2} 0'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [T_ratio_comp]
    type = ParsedPostprocessor
    pp_names = 'T_in_comp T_out_comp'
    expression = '(T_out_comp - T_in_comp) / T_out_comp'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [mfr_comp]
    type = ADFlowJunctionFlux1Phase
    boundary = pipe1:out
    connection_index = 0
    equation = mass
    junction = compressor
  []

  ##########################
  # turbine
  ##########################

  [turb_dissipation_torque]
    type = ElementAverageValue
    variable = dissipation_torque
    block = 'turbine'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [turb_isentropic_torque]
    type = ElementAverageValue
    variable = isentropic_torque
    block = 'turbine'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [turb_friction_torque]
    type = ElementAverageValue
    variable = friction_torque
    block = 'turbine'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [turbine_torque]
    type = ParsedPostprocessor
    pp_names = 'turb_dissipation_torque turb_isentropic_torque turb_friction_torque'
    expression = 'turb_dissipation_torque + turb_isentropic_torque + turb_friction_torque'
  []
  [p_in_turb]
    type = PointValue
    variable = p
    point = '${x6_out} ${y6} 0'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [p_out_turb]
    type = PointValue
    variable = p
    point = '${x7_in} ${y7} 0'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [p_ratio_turb]
    type = ParsedPostprocessor
    pp_names = 'p_in_turb p_out_turb'
    expression = 'p_in_turb / p_out_turb'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [T_in_turb]
    type = PointValue
    variable = T
    point = '${x6_out} ${y6} 0'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [T_out_turb]
    type = PointValue
    variable = T
    point = '${x7_in} ${y7} 0'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [mfr_turb]
    type = ADFlowJunctionFlux1Phase
    boundary = pipe6:out
    connection_index = 0
    equation = mass
    junction = turbine
  []

  ##########################
  # Recuperator
  ##########################

  [cold_leg_in]
    type = PointValue
    variable = T
    point = '${x3} ${cold_leg_in} 0'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [cold_leg_out]
    type = PointValue
    variable = T
    point = '${x3} ${cold_leg_out} 0'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [hot_leg_in]
    type = PointValue
    variable = T
    point = '${x8} ${hot_leg_in} 0'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [hot_leg_out]
    type = PointValue
    variable = T
    point = '${x8} ${hot_leg_out} 0'
    execute_on = 'INITIAL TIMESTEP_END'
  []

  ##########################
  # Reactor
  ##########################

  [reactor_inlet]
    type = PointValue
    variable = T
    point = '${x4} ${y4} 0'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [reactor_outlet]
    type = PointValue
    variable = T
    point = '${x5} ${y5_in} 0'
    execute_on = 'INITIAL TIMESTEP_END'
  []
[]

[Executioner]
  type = Transient
  scheme = 'bdf2'

  end_time = ${t3}
  [TimeStepper]
    type = IterationAdaptiveDT
    dt = 0.01
    growth_factor = 1.1
    cutback_factor = 0.9
  []
  dtmin = 1e-5
  dtmax = 1000
  steady_state_detection = true
  steady_state_start_time = 200000

  solve_type = NEWTON
  nl_rel_tol = 1e-8
  nl_abs_tol = 1e-8
  nl_max_its = 15

  l_tol = 1e-4
  l_max_its = 10

  petsc_options_iname  = '-pc_type'
  petsc_options_value  = ' lu     '
[]

[Outputs]
  [e]
    type = Exodus
    file_base = 'recuperated_brayton_cycle_out'
  []
  [csv]
    type = CSV
    file_base = 'recuperated_brayton_cycle'
    execute_vector_postprocessors_on = 'INITIAL'
  []
  [console]
    type = Console
    show = 'shaft_speed p_ratio_comp p_ratio_turb pressure_ratio pressure_ratio'
  []
[]

(modules/thermal_hydraulics/test/tests/problems/william_louis/4pipes_closed.i)

# Junction of 4 pipes:
#
#        4
#        |
# 1 -----*----- 3
#        |
#        2
#
# The left end of Pipe 1 is a high-pressure region, and the rest of the system
# is at a low pressure.
#
# All pipes are closed.

end_time = 0.07

D_pipe = 0.01
A_pipe = ${fparse 0.25 * pi * D_pipe^2}
length_pipe1_HP = 0.53
length_pipe1_LP = 3.10
length_pipe2 = 2.595
length_pipe3 = 1.725
length_pipe4 = 0.845

x_junction = ${fparse length_pipe1_HP + length_pipe1_LP}

# Numbers of elements correspond to dx ~ 1/3 cm
n_elems_pipe1_HP = 159
n_elems_pipe1_LP = 930
n_elems_pipe2 = 779
n_elems_pipe3 = 518
n_elems_pipe4 = 254

S_junction = ${fparse 4 * A_pipe}
r_junction = ${fparse sqrt(S_junction / (4 * pi))}
V_junction = ${fparse 4/3 * pi * r_junction^3}

p_low = 1e5
p_high = 1.15e5

T_initial = 283.5690633 # at p = 1e5 Pa, rho = 1.23 kg/m^3

cfl = 0.95

[GlobalParams]
  # common FlowChannel1Phase parameters
  A = ${A_pipe}
  initial_T = ${T_initial}
  initial_vel = 0
  fp = fp_air
  closures = closures
  f = 0
  gravity_vector = '0 0 0'
  scaling_factor_1phase = '1 1 1e-5'
[]

[FluidProperties]
  [fp_air]
    type = IdealGasFluidProperties
    gamma = 1.4
    molar_mass = 0.029
  []
[]

[Closures]
  [closures]
    type = Closures1PhaseSimple
  []
[]

[Functions]
  [initial_p_pipe1_fn]
    type = PiecewiseConstant
    axis = x
    x = '0 ${length_pipe1_HP}'
    y = '${p_high} ${p_low}'
  []
[]

[Components]
  [pipe1_wall]
    type = SolidWall1Phase
    input = 'pipe1:in'
  []
  [pipe1]
    type = FlowChannel1Phase
    position = '0 0 0'
    orientation = '1 0 0'
    length = '${length_pipe1_HP} ${length_pipe1_LP}'
    n_elems = '${n_elems_pipe1_HP} ${n_elems_pipe1_LP}'
    initial_p = initial_p_pipe1_fn
  []

  [junction]
    type = VolumeJunction1Phase
    position = '${x_junction} 0 0'
    connections = 'pipe1:out pipe2:in pipe3:in pipe4:in'
    initial_p = ${p_low}
    initial_T = ${T_initial}
    initial_vel_x = 0
    initial_vel_y = 0
    initial_vel_z = 0
    volume = ${V_junction}
    scaling_factor_rhoEV = 1e-5
    apply_velocity_scaling = true
  []

  [pipe2]
    type = FlowChannel1Phase
    position = '${x_junction} 0 0'
    orientation = '0 -1 0'
    length = ${length_pipe2}
    n_elems = ${n_elems_pipe2}
    initial_p = ${p_low}
  []
  [pipe2_wall]
    type = SolidWall1Phase
    input = 'pipe2:out'
  []

  [pipe3]
    type = FlowChannel1Phase
    position = '${x_junction} 0 0'
    orientation = '1 0 0'
    length = ${length_pipe3}
    n_elems = ${n_elems_pipe3}
    initial_p = ${p_low}
  []
  [pipe3_wall]
    type = SolidWall1Phase
    input = 'pipe3:out'
  []

  [pipe4]
    type = FlowChannel1Phase
    position = '${x_junction} 0 0'
    orientation = '0 1 0'
    length = ${length_pipe4}
    n_elems = ${n_elems_pipe4}
    initial_p = ${p_low}
  []
  [pipe4_wall]
    type = SolidWall1Phase
    input = 'pipe4:out'
  []
[]

[Postprocessors]
  [cfl_dt]
    type = ADCFLTimeStepSize
    CFL = ${cfl}
    c_names = 'c'
    vel_names = 'vel'
  []
  [p_pipe1_048]
    type = PointValue
    variable = p
    point = '${fparse x_junction - 0.48} 0 0'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [p_pipe2_052]
    type = PointValue
    variable = p
    point = '${fparse x_junction} -0.52 0'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [p_pipe3_048]
    type = PointValue
    variable = p
    point = '${fparse x_junction + 0.48} 0 0'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [p_pipe4_043]
    type = PointValue
    variable = p
    point = '${fparse x_junction} 0.43 0'
    execute_on = 'INITIAL TIMESTEP_END'
  []
[]

[Preconditioning]
  [pc]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  end_time = ${end_time}

  [TimeIntegrator]
    type = ExplicitSSPRungeKutta
    order = 1
  []

  [TimeStepper]
    type = PostprocessorDT
    postprocessor = cfl_dt
  []
  abort_on_solve_fail = true

  solve_type = LINEAR
[]

[Times]
  [output_times]
    type = TimeIntervalTimes
    time_interval = 7e-4
  []
[]

[Outputs]
  file_base = '4pipes_closed'
  [csv]
    type = CSV
    show = 'p_pipe1_048 p_pipe2_052 p_pipe3_048 p_pipe4_043'
    sync_only = true
    sync_times_object = output_times
  []
  [console]
    type = Console
    execute_postprocessors_on = 'NONE'
  []
[]

(modules/thermal_hydraulics/test/tests/problems/william_louis/3pipes_open.i)

# Junction of 3 pipes:
#
#   1     3
# -----*-----
#      | 2
#
# The left end of Pipe 1 is a high-pressure region, and the rest of the system
# is at a low pressure.
#
# Pipe 1 is closed, while Pipes 2 and 3 are open.

end_time = 0.07

D_pipe = 0.01
A_pipe = ${fparse 0.25 * pi * D_pipe^2}
length_pipe1_HP = 0.53
length_pipe1_LP = 3.10
length_pipe2 = 2.595
length_pipe3 = 1.725

x_junction = ${fparse length_pipe1_HP + length_pipe1_LP}

# Numbers of elements correspond to dx ~ 1/3 cm
n_elems_pipe1_HP = 159
n_elems_pipe1_LP = 930
n_elems_pipe2 = 779
n_elems_pipe3 = 518

S_junction = ${fparse 3 * A_pipe}
r_junction = ${fparse sqrt(S_junction / (4 * pi))}
V_junction = ${fparse 4/3 * pi * r_junction^3}

p_low = 1e5
p_high = 1.15e5

T_low  = 283.5690633 # at p = 1e5 Pa,    rho = 1.23 kg/m^3
T_high = 283.5690633 # at p = 1.15e5 Pa, rho = 1.4145 kg/m^3

cfl = 0.95

[GlobalParams]
  # common FlowChannel1Phase parameters
  A = ${A_pipe}
  initial_vel = 0
  fp = fp_air
  closures = closures
  f = 0
  gravity_vector = '0 0 0'
  scaling_factor_1phase = '1 1 1e-5'
[]

[FluidProperties]
  [fp_air]
    type = IdealGasFluidProperties
    gamma = 1.4
    molar_mass = 0.029
  []
[]

[Closures]
  [closures]
    type = Closures1PhaseSimple
  []
[]

[Functions]
  [initial_T_pipe1_fn]
    type = PiecewiseConstant
    axis = x
    x = '0 ${length_pipe1_HP}'
    y = '${T_high} ${T_low}'
  []
  [initial_p_pipe1_fn]
    type = PiecewiseConstant
    axis = x
    x = '0 ${length_pipe1_HP}'
    y = '${p_high} ${p_low}'
  []
[]

[Components]
  [pipe1_wall]
    type = SolidWall1Phase
    input = 'pipe1:in'
  []
  [pipe1]
    type = FlowChannel1Phase
    position = '0 0 0'
    orientation = '1 0 0'
    length = '${length_pipe1_HP} ${length_pipe1_LP}'
    n_elems = '${n_elems_pipe1_HP} ${n_elems_pipe1_LP}'
    initial_p = initial_p_pipe1_fn
    initial_T = initial_T_pipe1_fn
  []

  [junction]
    type = VolumeJunction1Phase
    position = '${x_junction} 0 0'
    connections = 'pipe1:out pipe2:in pipe3:in'
    initial_p = ${p_low}
    initial_T = ${T_low}
    initial_vel_x = 0
    initial_vel_y = 0
    initial_vel_z = 0
    volume = ${V_junction}
    scaling_factor_rhoEV = 1e-5
    apply_velocity_scaling = true
  []

  [pipe2]
    type = FlowChannel1Phase
    position = '${x_junction} 0 0'
    orientation = '0 -1 0'
    length = ${length_pipe2}
    n_elems = ${n_elems_pipe2}
    initial_p = ${p_low}
    initial_T = ${T_low}
  []
  [pipe2_outlet]
    type = Outlet1Phase
    input = 'pipe2:out'
    p = ${p_low}
  []

  [pipe3]
    type = FlowChannel1Phase
    position = '${x_junction} 0 0'
    orientation = '1 0 0'
    length = ${length_pipe3}
    n_elems = ${n_elems_pipe3}
    initial_p = ${p_low}
    initial_T = ${T_low}
  []
  [pipe3_outlet]
    type = Outlet1Phase
    input = 'pipe3:out'
    p = ${p_low}
  []
[]

[Postprocessors]
  [cfl_dt]
    type = ADCFLTimeStepSize
    CFL = ${cfl}
    c_names = 'c'
    vel_names = 'vel'
  []
  [p_pipe1_048]
    type = PointValue
    variable = p
    point = '${fparse x_junction - 0.48} 0 0'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [p_pipe2_052]
    type = PointValue
    variable = p
    point = '${fparse x_junction} -0.52 0'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [p_pipe3_048]
    type = PointValue
    variable = p
    point = '${fparse x_junction + 0.48} 0 0'
    execute_on = 'INITIAL TIMESTEP_END'
  []
[]

[Preconditioning]
  [pc]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  end_time = ${end_time}

  [TimeIntegrator]
    type = ExplicitSSPRungeKutta
    order = 1
  []

  [TimeStepper]
    type = PostprocessorDT
    postprocessor = cfl_dt
  []
  abort_on_solve_fail = true

  solve_type = LINEAR
[]

[Times]
  [output_times]
    type = TimeIntervalTimes
    time_interval = 7e-4
  []
[]

[Outputs]
  file_base = '3pipes_open'
  [csv]
    type = CSV
    show = 'p_pipe1_048 p_pipe2_052 p_pipe3_048'
    sync_only = true
    sync_times_object = output_times
  []
  [console]
    type = Console
    execute_postprocessors_on = 'NONE'
  []
[]

(modules/thermal_hydraulics/test/tests/problems/abrupt_area_change_liquid/with_junction.i)

# Version with junction

!include base_params.i

# For equivalent comparison to the unsplit case, we reduce the length of the
# right pipe by one element
dx = ${fparse lengthL / NL}
NR_minus_junction = ${fparse NR - 1}
lengthR_minus_junction = ${fparse lengthR - dx}
xR_minus_junction = ${fparse xR + dx}

xJ = ${fparse lengthL + 0.5 * dx}
AJ = ${fparse AL + AR}
RJ = ${fparse sqrt(AJ / (4 * pi))} # A = 4 pi R^2
VJ = ${fparse 4/3 * pi * RJ^3}

!include base.i

[Components]
  [pipeL]
    type = FlowChannel1Phase
    position = '0 0 0'
    orientation = '1 0 0'
    length = ${lengthL}
    n_elems = ${NL}
    A = ${AL}
  []

  [pipeR]
    type = FlowChannel1Phase
    position = '${xR_minus_junction} 0 0'
    orientation = '1 0 0'
    length = ${lengthR_minus_junction}
    n_elems = ${NR_minus_junction}
    A = ${AR}
  []

  [junction]
    type = VolumeJunction1Phase
    connections = 'pipeL:out pipeR:in'
    position = '${xJ} 0 0'
    volume = ${VJ}
    initial_vel_x = 0
    initial_vel_y = 0
    initial_vel_z = 0
    scaling_factor_rhoEV = 1e-5
    apply_velocity_scaling = true
  []

  [left_boundary]
    type = FreeBoundary1Phase
    input = 'pipeL:in'
  []

  [right_boundary]
    type = FreeBoundary1Phase
    input = 'pipeR:out'
  []
[]

[VectorPostprocessors]
  [vpp]
    type = ADSampler1DReal
    block = 'pipeL pipeR'
    property = 'p vel'
    sort_by = x
    execute_on = 'FINAL'
  []
[]

[Outputs]
  file_base = 'with_junction'
[]

(modules/thermal_hydraulics/test/tests/components/volume_junction_1phase/phy.unequal_area.i)

# Junction between 2 pipes where the second has half the area of the first.
# The momentum density of the second should be twice that of the first.

[GlobalParams]
  gravity_vector = '0 0 0'

  initial_T = 250
  initial_p = 1e5
  initial_vel = 1
  initial_vel_x = 1
  initial_vel_y = 0
  initial_vel_z = 0

  f = 0

  fp = eos

  scaling_factor_1phase = '1 1 1e-5'

  closures = simple_closures
[]

[FluidProperties]
  [eos]
    type = StiffenedGasFluidProperties
    gamma = 1.4
    cv = 725
    p_inf = 0
    q = 0
    q_prime = 0
  []
[]

[Closures]
  [simple_closures]
    type = Closures1PhaseSimple
  []
[]

[Components]
  [inlet]
    type = InletDensityVelocity1Phase
    input = 'pipe1:in'
    rho = 1.37931034483
    vel = 1
  []

  [pipe1]
    type = FlowChannel1Phase
    position = '0 0 0'
    orientation = '1 0 0'
    length = 1
    A = 1
    n_elems = 20
  []

  [junction]
    type = VolumeJunction1Phase
    connections = 'pipe1:out pipe2:in'
    position = '1 0 0'
    volume = 1e-8
    use_scalar_variables = false
  []

  [pipe2]
    type = FlowChannel1Phase
    position = '1 0 0'
    orientation = '1 0 0'
    length = 1
    A = 0.5
    n_elems = 20
  []

  [outlet]
    type = Outlet1Phase
    input = 'pipe2:out'
    p = 1e5
  []
[]

[Preconditioning]
  [pc]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  scheme = 'bdf2'

  solve_type = 'NEWTON'
  line_search = 'basic'
  nl_rel_tol = 0
  nl_abs_tol = 1e-6
  nl_max_its = 10

  l_tol = 1e-10
  l_max_its = 10

  petsc_options_iname = '-pc_type'
  petsc_options_value = 'lu'

  start_time = 0
  end_time = 3
  dt = 0.1

  abort_on_solve_fail = true
[]

[Postprocessors]
  # These post-processors are used to test that the outlet side of the junction,
  # which has half the area of the inlet side, has twice the momentum density
  # that the inlet side does.
  [rhouA_pipe1]
    type = SideAverageValue
    variable = rhouA
    boundary = pipe1:out
  []
  [rhouA_pipe2]
    type = SideAverageValue
    variable = rhouA
    boundary = pipe2:out
  []
  [test_rel_err]
    type = RelativeDifferencePostprocessor
    value1 = rhouA_pipe1
    value2 = rhouA_pipe2
  []
[]

[Outputs]
  [out]
    type = CSV
    show = test_rel_err
    execute_on = 'final'
  []
[]

(modules/thermal_hydraulics/test/tests/components/volume_junction_1phase/t_junction_1phase.i)

# Junction between 3 pipes, 1 of which goes to a dead-end. All ends are walls,
# and 1 of the pipes is pressurized higher than the others.

A_big = 1
A_small = 0.5

[GlobalParams]
  gravity_vector = '0 0 0'

  scaling_factor_1phase = '1 1 1e-5'
  scaling_factor_rhoV  = 1
  scaling_factor_rhouV = 1
  scaling_factor_rhovV = 1
  scaling_factor_rhowV = 1
  scaling_factor_rhoEV = 1e-5

  initial_T = 300
  initial_vel = 0

  n_elems = 20
  length = 1

  f = 0

  fp = fp

  rdg_slope_reconstruction = minmod

  closures = simple_closures
[]

[FluidProperties]
  [fp]
    type = StiffenedGasFluidProperties
    gamma = 1.4
    cv = 725
    q = 0
    q_prime = 0
    p_inf = 0
  []
[]

[Closures]
  [simple_closures]
    type = Closures1PhaseSimple
  []
[]

[Components]
  [pipe1]
    type = FlowChannel1Phase
    position = '0 0 0'
    orientation = '1 0 0'
    A = ${A_big}
    # This pipe is pressurized higher than the others.
    initial_p = 1.05e5
  []

  [pipe2]
    type = FlowChannel1Phase
    position = '1 0 0'
    orientation = '1 0 0'
    A = ${A_big}
    initial_p = 1e5
  []

  [pipe3]
    type = FlowChannel1Phase
    position = '1 0 0'
    orientation = '0 1 0'
    # This pipe is smaller than the others.
    A = ${A_small}
    initial_p = 1e5
  []

  [junction]
    type = VolumeJunction1Phase
    connections = 'pipe1:out pipe2:in pipe3:in'

    position = '1 0 0'
    volume = 0.37

    initial_p = 1e5
    initial_vel_x = 0
    initial_vel_y = 0
    initial_vel_z = 0

    use_scalar_variables = false
  []

  [pipe1_wall]
    type = SolidWall1Phase
    input = 'pipe1:in'
  []
  [pipe2_wall]
    type = SolidWall1Phase
    input = 'pipe2:out'
  []
  [pipe3_wall]
    type = SolidWall1Phase
    input = 'pipe3:out'
  []
[]

[Preconditioning]
  [pc]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  scheme = 'bdf2'

  start_time = 0
  end_time = 5
  dt = 0.05
  num_steps = 5
  abort_on_solve_fail = true

  solve_type = NEWTON
  petsc_options_iname = '-pc_type'
  petsc_options_value = 'lu'
  nl_rel_tol = 1e-8
  nl_abs_tol = 1e-8
  nl_max_its = 10

  l_tol = 1e-3
  l_max_its = 10

  [Quadrature]
    type = GAUSS
    order = SECOND
  []
[]

[Postprocessors]
  # mass conservation
  [mass_pipes]
    type = ElementIntegralVariablePostprocessor
    variable = rhoA
    block = 'pipe1 pipe2 pipe3'
    execute_on = 'initial timestep_end'
  []
  [mass_junction]
    type = ElementAverageValue
    variable = rhoV
    block = 'junction'
    execute_on = 'initial timestep_end'
  []
  [mass_tot]
    type = SumPostprocessor
    values = 'mass_pipes mass_junction'
    execute_on = 'initial timestep_end'
  []
  [mass_tot_change]
    type = ChangeOverTimePostprocessor
    change_with_respect_to_initial = true
    postprocessor = mass_tot
    compute_relative_change = true
    execute_on = 'initial timestep_end'
  []

  # energy conservation
  [E_pipes]
    type = ElementIntegralVariablePostprocessor
    variable = rhoEA
    block = 'pipe1 pipe2 pipe3'
    execute_on = 'initial timestep_end'
  []
  [E_junction]
    type = ElementAverageValue
    variable = rhoEV
    block = 'junction'
    execute_on = 'initial timestep_end'
  []
  [E_tot]
    type = SumPostprocessor
    values = 'E_pipes E_junction'
    execute_on = 'initial timestep_end'
  []
  [E_tot_change]
    type = ChangeOverTimePostprocessor
    change_with_respect_to_initial = true
    postprocessor = E_tot
    compute_relative_change = true
    execute_on = 'initial timestep_end'
  []
[]

[Outputs]
  [out]
    type = CSV
    show = 'mass_tot_change E_tot_change'
  []
[]

(modules/thermal_hydraulics/test/tests/output/vector_velocity/test.i)

[GlobalParams]
  initial_vel = 0
  initial_vel_x = 0
  initial_vel_y = 0
  initial_vel_z = 0
  initial_p = 1e5
  initial_T = 300

  f = 0.1
  closures = simple_closures
  fp = fp
[]

[FluidProperties]
  [fp]
    type = IdealGasFluidProperties
  []
[]

[Closures]
  [simple_closures]
    type = Closures1PhaseSimple
  []
[]

[Components]
  [inlet]
    type = InletMassFlowRateTemperature1Phase
    input = 'fch1:in'
    m_dot = 1
    T = 300
  []

  [fch1]
    type = FlowChannel1Phase
    position = '0 0 0'
    orientation = '1 1 1'
    length = 1.73205
    n_elems = 5
    A = 1
  []

  [junction]
    type = VolumeJunction1Phase
    position = '1 1 1'
    connections = 'fch1:out fch2:out'
    volume = 0.1
    use_scalar_variables = false
  []

  [fch2]
    type = FlowChannel1Phase
    position = '2 2 2'
    orientation = '-1 -1 -1'
    length = 1.73205
    n_elems = 5
    A = 2
  []

  [outlet]
    type = Outlet1Phase
    input = 'fch2:in'
    p = 1e5
  []
[]

[Executioner]
  type = Transient
  dt = 0.5
  num_steps = 50

  solve_type = NEWTON
  line_search = basic
  petsc_options_iname = '-pc_type'
  petsc_options_value = 'lu'

  nl_abs_tol = 1e-6
  l_tol = 1e-03

  automatic_scaling = true
[]

[Outputs]
  print_linear_converged_reason = false
  print_nonlinear_converged_reason = false
  print_linear_residuals = false

  [out]
    type = Exodus
    sync_only = false
    sync_times = '0 5 10 15 20 25'
    show = 'vel_x vel_y vel_z'
  []
[]

(modules/thermal_hydraulics/test/tests/components/volume_junction_1phase/junction_with_calorifically_imperfect_gas.i)

# This input file tests compatibility of VolumeJunction1Phase and CaloricallyImperfectGas.
# Loss coefficient is applied in first junction.
# Expected pressure drop ~0.5*K*rho_in*vel_in^2=0.5*100*3.219603*1 = 160.9 Pa

T_in = 523.0
vel = 1
p_out = 7e6

[GlobalParams]
  initial_p = ${p_out}
  initial_vel = ${vel}
  initial_T = ${T_in}
  gravity_vector = '0 0 0'
  closures = simple_closures
  n_elems = 3
  f = 0
  scaling_factor_1phase = '1 1 1e-5'
  scaling_factor_rhoV = '1e2'
  scaling_factor_rhowV = '1e-2'
  scaling_factor_rhoEV = '1e-5'
[]

[Functions]
  [e_fn]
    type = PiecewiseLinear
    x = '100   280 300 350 400 450 500 550 600 700 800 900 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 5000'
    y = '783.9 2742.3 2958.6 3489.2 4012.7 4533.3 5053.8 5574 6095.1 7140.2 8192.9 9256.3 10333.6 12543.9 14836.6 17216.3 19688.4 22273.7 25018.3 28042.3 31544.2 35818.1 41256.5 100756.5'
    scale_factor = 1e3
  []

  [mu_fn]
    type = PiecewiseLinear
    x = '100   280 300 350 400 450 500 550 600 700 800 900 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 5000'
    y = '85.42 85.42 89.53 99.44 108.9 117.98 126.73 135.2 143.43 159.25 174.36 188.9 202.96 229.88 255.5 280.05 303.67 326.45 344.97 366.49 387.87 409.48 431.86 431.86'
    scale_factor = 1e-7
  []

  [k_fn]
    type = PiecewiseLinear
    x = '100 280 300 350 400 450 500 550 600 700 800 900 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 5000'
    y = '186.82 186.82 194.11 212.69 231.55 250.38 268.95 287.19 305.11 340.24 374.92 409.66 444.75 511.13 583.42 656.44 733.32 826.53 961.15 1180.38 1546.31 2135.49 3028.08 3028.08'
    scale_factor = 1e-3
  []
[]

[FluidProperties]
  [fp]
    type = CaloricallyImperfectGas
    molar_mass = 0.002
    e = e_fn
    k = k_fn
    mu = mu_fn
    min_temperature = 100
    max_temperature = 5000
    out_of_bound_error = false
  []
[]

[Closures]
  [simple_closures]
    type = Closures1PhaseSimple
  []
[]

[Components]
  [inlet_bc]
    type = InletVelocityTemperature1Phase
    input = 'inlet:in'
    vel = ${vel}
    T = ${T_in}
  []
  [inlet]
    type = FlowChannel1Phase
    fp = fp
    position = '0 0 11'
    orientation = '0 0 -1'
    length = 1
    A = 5
  []
  [inlet_plenum]
    type = VolumeJunction1Phase
    position = '0 0 10'
    initial_vel_x = 0
    initial_vel_y = 0
    initial_vel_z = ${vel}
    K = 100
    connections = 'inlet:out channel1:in channel2:in'
    volume = 1
    use_scalar_variables = false
  []
  [channel1]
    type = FlowChannel1Phase
    fp = fp
    position = '0 0 10'
    orientation = '0 0 -1'
    length = 10
    A = 4
    D_h = 1
  []
  [channel2]
    type = FlowChannel1Phase
    fp = fp
    position = '0 0 10'
    orientation = '0 0 -1'
    length = 10
    A = 1
    D_h = 1
  []
  [outlet_plenum]
    type = VolumeJunction1Phase
    position = '0 0 0'
    initial_vel_x = 0
    initial_vel_y = 0
    initial_vel_z = ${vel}
    connections = 'channel1:out channel2:out outlet:in'
    volume = 1
    use_scalar_variables = false
  []
  [outlet]
    type = FlowChannel1Phase
    fp = fp
    position = '0 0 0'
    orientation = '0 0 -1'
    length = 1
    A = 5
  []
  [outlet_bc]
    type = Outlet1Phase
    p = ${p_out}
    input = 'outlet:out'
  []
[]

[Postprocessors]
  [p_in]
    type = SideAverageValue
    variable = p
    boundary = inlet:in
  []
  [p_out]
    type = SideAverageValue
    variable = p
    boundary = outlet:out
  []
  [Delta_p]
    type = DifferencePostprocessor
    value1 = p_out
    value2 = p_in
  []
  [inlet_in_m_dot]
    type = ADFlowBoundaryFlux1Phase
    boundary = 'inlet_bc'
    equation = mass
  []
  [inlet_out_m_dot]
    type = ADFlowJunctionFlux1Phase
    boundary = 'inlet:out'
    connection_index = 0
    junction = inlet_plenum
    equation = mass
  []

  [channel1_in_m_dot]
    type = ADFlowJunctionFlux1Phase
    boundary = 'channel1:in'
    connection_index = 1
    junction = inlet_plenum
    equation = mass
  []
  [channel1_out_m_dot]
    type = ADFlowJunctionFlux1Phase
    boundary = 'channel1:out'
    connection_index = 0
    junction = outlet_plenum
    equation = mass
  []

  [channel2_in_m_dot]
    type = ADFlowJunctionFlux1Phase
    boundary = 'channel2:in'
    connection_index = 2
    junction = inlet_plenum
    equation = mass
  []
  [channel2_out_m_dot]
    type = ADFlowJunctionFlux1Phase
    boundary = 'channel2:out'
    connection_index = 1
    junction = outlet_plenum
    equation = mass
  []

  [outlet_in_m_dot]
    type = ADFlowJunctionFlux1Phase
    boundary = 'outlet:in'
    connection_index = 2
    junction = outlet_plenum
    equation = mass
  []
  [outlet_out_m_dot]
    type = ADFlowBoundaryFlux1Phase
    boundary = 'outlet_bc'
    equation = mass
  []

  [net_mass_flow_rate_domain]
    type = LinearCombinationPostprocessor
    pp_names = 'inlet_in_m_dot outlet_out_m_dot'
    pp_coefs = '1 -1'
  []
  [net_mass_flow_rate_volume_junction]
    type = LinearCombinationPostprocessor
    pp_names = 'inlet_out_m_dot channel1_in_m_dot channel2_in_m_dot'
    pp_coefs = '1 -1 -1'
  []
[]

[Preconditioning]
  [smp]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  scheme = bdf2
  start_time = 0
  end_time = 20
  [TimeStepper]
    type = IterationAdaptiveDT
    dt = 1
    optimal_iterations = 8
    iteration_window = 2
  []
  timestep_tolerance = 1e-6
  abort_on_solve_fail = true

  line_search = basic
  nl_rel_tol = 1e-8
  nl_abs_tol = 4e-8
  nl_max_its = 25
  l_tol = 1e-3
  l_max_its = 5
  petsc_options = '-snes_converged_reason'
  petsc_options_iname = '-pc_type'
  petsc_options_value = ' lu     '
[]

[Outputs]
  [out]
    type = CSV
    execute_on = 'FINAL'
    show = 'net_mass_flow_rate_domain net_mass_flow_rate_volume_junction Delta_p'
  []
[]

(modules/thermal_hydraulics/test/tests/misc/coupling_mD_flow/thm_non_overlapping.i)

T_in = 523.0
mdot = 10
pout = 7e6

[GlobalParams]
  initial_p = ${pout}
  initial_vel = 1
  initial_T = ${T_in}
  gravity_vector = '0 0 0'
  closures = simple_closures
  n_elems = 5

  scaling_factor_1phase = '1 1e-2 1e-5'
  f = 1
[]

[FluidProperties]
  [fp]
    type = IdealGasFluidProperties
    gamma = 1.66
    molar_mass = 0.004
  []
[]

[Closures]
  [simple_closures]
    type = Closures1PhaseSimple
  []
[]

[Components]
  [inlet_bc]
    type = InletMassFlowRateTemperature1Phase
    input = 'inlet:in'
    m_dot = ${mdot}
    T = ${T_in}
  []

  [inlet]
    type = FlowChannel1Phase
    fp = fp
    position = '0 0 11'
    orientation = '0 0 -1'
    length = 1
    A = 1
  []

  [inlet_plenum]
    type = VolumeJunction1Phase
    position = '0 0 10'
    initial_vel_x = 0
    initial_vel_y = 0
    initial_vel_z = 1
    connections = 'inlet:out bypass:in core_top:in'
    volume = 1
    use_scalar_variables = false
  []

  [bypass]
    type = FlowChannel1Phase
    fp = fp
    position = '2 0 10'
    orientation = '0 0 -1'
    length = 10
    A = 0.01
  []

  [core_top]
    type = FlowChannel1Phase
    fp = fp
    position = '0 0 10'
    orientation = '0 0 -1'
    length = 0.1
    A = 9
  []

  [core_top_bc]
    type = Outlet1Phase
    p = ${pout}
    input = 'core_top:out'
  []

  [core_bottom_bc]
    type = InletMassFlowRateTemperature1Phase
    input = 'core_bottom:in'
    m_dot = ${mdot}
    T = ${T_in}
  []

  [core_bottom]
    type = FlowChannel1Phase
    fp = fp
    position = '0 0 0.1'
    orientation = '0 0 -1'
    length = 0.1
    A = 9
  []

  [outlet_plenum]
    type = VolumeJunction1Phase
    position = '0 0 0'
    initial_vel_x = 1
    initial_vel_y = 0
    initial_vel_z = 1
    connections = 'bypass:out core_bottom:out outlet:in'
    volume = 1
    use_scalar_variables = false
  []

  [outlet]
    type = FlowChannel1Phase
    fp = fp
    position = '0 0 0'
    orientation = '0 0 -1'
    length = 1
    A = 1
  []

  [outlet_bc]
    type = Outlet1Phase
    p = ${pout}
    input = 'outlet:out'
  []
[]

[ControlLogic]
  [set_core_inlet_pressure]
    type = SetComponentRealValueControl
    component = core_top_bc
    parameter = p
    value = core_inlet_pressure
  []

  [set_core_outlet_mdot]
    type = SetComponentRealValueControl
    component = core_bottom_bc
    parameter = m_dot
    value = core_outlet_mdot
  []

  [set_core_outlet_temperature]
    type = SetComponentRealValueControl
    component = core_bottom_bc
    parameter = T
    value = core_outlet_temperature
  []
[]

[Postprocessors]
  [core_inlet_pressure]
    type = Receiver
    default = ${pout}
  []

  [core_outlet_mdot]
    type = Receiver
    default = ${mdot}
  []

  [core_outlet_temperature]
    type = Receiver
    default = ${T_in}
  []

  [core_outlet_pressure]
    type = SideAverageValue
    variable = p
    boundary = 'core_bottom:in'
    execute_on = 'INITIAL LINEAR TIMESTEP_END'
  []

  [core_inlet_mdot]
    type = SideAverageValue
    variable = rhouA
    boundary = 'core_top:out'
    execute_on = 'INITIAL LINEAR TIMESTEP_END'
  []

  [core_inlet_temperature]
    type = SideAverageValue
    variable = T
    boundary = 'core_top:out'
    execute_on = 'INITIAL LINEAR TIMESTEP_END'
  []

  [bypass_inlet_pressure]
    type = SideAverageValue
    variable = p
    boundary = 'bypass:in'
  []

  [bypass_outlet_pressure]
    type = SideAverageValue
    variable = p
    boundary = 'bypass:out'
  []

  [bypass_pressure_drop]
    type = DifferencePostprocessor
    value1 = bypass_inlet_pressure
    value2 = bypass_outlet_pressure
  []

  [bypass_mdot]
    type = SideAverageValue
    variable = rhouA
    boundary = 'bypass:out'
    execute_on = 'INITIAL LINEAR TIMESTEP_END'
  []

  [inlet_mdot]
    type = SideAverageValue
    variable = rhouA
    boundary = 'inlet:in'
    execute_on = 'INITIAL LINEAR TIMESTEP_END'
  []

  [outlet_mdot]
    type = SideAverageValue
    variable = rhouA
    boundary = 'outlet:out'
    execute_on = 'INITIAL LINEAR TIMESTEP_END'
  []
[]

[Preconditioning]
  [smp]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  timestep_tolerance = 1e-6
  start_time = 0
  end_time = 100
  dt = 0.01
  line_search = l2
  nl_rel_tol = 1e-6
  nl_abs_tol = 1e-4
  nl_max_its = 25
  l_tol = 1e-3
  l_max_its = 20
  petsc_options = '-snes_converged_reason'
  petsc_options_iname = '-pc_type'
  petsc_options_value = ' lu     '
[]

[Outputs]
  exodus = true
[]

(modules/thermal_hydraulics/test/tests/misc/displaced_components/displaced_components.i)

[GlobalParams]
  initial_T = 300
  initial_p = 1e5
  initial_vel = 0
  initial_vel_x = 0
  initial_vel_y = 0
  initial_vel_z = 0
  gravity_vector = '0 0 0'
  scaling_factor_1phase = '1.e0 1.e-4 1.e-6'

  closures = simple_closures
[]

[FluidProperties]
  [eos]
    type = StiffenedGasFluidProperties
    gamma = 2.35
    q = -1167e3
    q_prime = 0
    p_inf = 1.e9
    cv = 1816
  []
[]

[Closures]
  [simple_closures]
    type = Closures1PhaseSimple
  []
[]

[Components]
  [pipe1]
    type = FlowChannel1Phase
    fp = eos
    position = '0 0 0'
    orientation = '1 0 0'
    A = 1.
    D_h = 1.12837916709551
    f = 0
    length = 1
    n_elems = 10
  []

  [pipe2]
    type = FlowChannel1Phase
    fp = eos
    position = '0 0 0'
    orientation = '0 1 0'
    A = 1.
    D_h = 1.12837916709551
    f = 0
    length = 1
    n_elems = 10
  []

  [pipe3]
    type = FlowChannel1Phase
    fp = eos
    position = '0 0 0'
    orientation = '0 0 1'
    A = 1.
    D_h = 1.12837916709551
    f = 0
    length = 1
    n_elems = 10
  []

  [junction]
    type = VolumeJunction1Phase
    connections = 'pipe1:in pipe2:in pipe3:in'
    position = '0 0 0'
    volume = 1e-5
    use_scalar_variables = false
  []

  [in1]
    type = SolidWall1Phase
    input = 'pipe1:out'
  []
  [in2]
    type = SolidWall1Phase
    input = 'pipe2:out'
  []
  [in3]
    type = SolidWall1Phase
    input = 'pipe3:out'
  []
[]

[Preconditioning]
  [SMP_PJFNK]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  scheme = 'bdf2'

  start_time = 0
  dt = 1e-5
  num_steps = 1
  abort_on_solve_fail = true

  solve_type = 'PJFNK'
  nl_rel_tol = 1e-5
  nl_abs_tol = 1e-6
  nl_max_its = 10

  l_tol = 1e-3
  l_max_its = 100
[]

[Outputs]
  exodus = true
  show = 'A'
[]

(modules/thermal_hydraulics/tutorials/single_phase_flow/04_loop.i)

T_in = 300. # K
m_dot_in = 1e-2 # kg/s
press = 10e5 # Pa

# core parameters
core_length = 1. # m
core_n_elems = 25
core_dia = '${units 2. cm -> m}'
core_pitch = '${units 8.7 cm -> m}'

# pipe parameters
pipe_dia = '${units 10. cm -> m}'
A_pipe = '${fparse 0.25 * pi * pipe_dia^2}'
A_core = '${fparse core_pitch^2 - 0.25 *pi * core_dia^2}'
P_wet_core = '${fparse 4*core_pitch + pi * core_dia}'
Dh_core = '${fparse 4 * A_core / P_wet_core}'

tot_power = 2000 # W

[GlobalParams]
  initial_p = ${press}
  initial_vel = 0.0001
  initial_T = ${T_in}
  initial_vel_x = 0
  initial_vel_y = 0
  initial_vel_z = 0
  gravity_vector = '0 0 0'

  rdg_slope_reconstruction = minmod
  scaling_factor_1phase = '1 1e-2 1e-4'
  scaling_factor_rhoV = 1
  scaling_factor_rhouV = 1e-2
  scaling_factor_rhovV = 1e-2
  scaling_factor_rhowV = 1e-2
  scaling_factor_rhoEV = 1e-4
  closures = simple_closures
  fp = he
[]

[FluidProperties]
  [he]
    type = IdealGasFluidProperties
    molar_mass = 4e-3
    gamma = 1.67
    k = 0.2556
    mu = 3.22639e-5
  []
[]

[Closures]
  [simple_closures]
    type = Closures1PhaseTHM
  []
[]

[SolidProperties]
  [steel]
    type = ThermalFunctionSolidProperties
    rho = 8050
    k = 45
    cp = 466
  []
[]

[Components]
  [total_power]
    type = TotalPower
    power = ${tot_power}
  []
  [up_pipe_1]
    type = FlowChannel1Phase
    position = '0 0 0'
    orientation = '0 0 1'
    length = 0.5
    n_elems = 15
    A = ${A_pipe}
    D_h = ${pipe_dia}
  []

  [jct1]
    type = JunctionParallelChannels1Phase
    position = '0 0 0.5'
    connections = 'up_pipe_1:out core_chan:in'
    volume = 1e-5
    use_scalar_variables = false
  []
  [core_chan]
    type = FlowChannel1Phase
    position = '0 0 0.5'
    orientation = '0 0 1'
    length = ${core_length}
    n_elems = ${core_n_elems}
    roughness = .0001
    A = '${A_core}'
    D_h = ${Dh_core}
  []

  [core_hs]
    type = HeatStructureCylindrical
    position = '0 0 0.5'
    orientation = '0 0 1'
    length = ${core_length}
    n_elems = ${core_n_elems}
    names = 'block'
    widths = '${fparse core_dia / 2.}'
    solid_properties = 'steel'
    solid_properties_T_ref = '300'
    n_part_elems = 3
  []

  [core_heating]
    type = HeatSourceFromTotalPower
    hs = core_hs
    regions = block
    power = total_power
  []

  [core_ht]
    type = HeatTransferFromHeatStructure1Phase
    flow_channel = core_chan
    hs = core_hs
    hs_side = outer
    P_hf = '${fparse pi * core_dia}'
  []

  [jct2]
    type = JunctionParallelChannels1Phase
    position = '0 0 1.5'
    connections = 'core_chan:out up_pipe_2:in'
    volume = 1e-5
    use_scalar_variables = false
  []

  [up_pipe_2]
    type = FlowChannel1Phase
    position = '0 0 1.5'
    orientation = '0 0 1'
    length = 0.5
    n_elems = 10
    A = ${A_pipe}
    D_h = ${pipe_dia}
  []

  [jct3]
    type = JunctionOneToOne1Phase
    connections = 'up_pipe_2:out top_pipe_1:in'
  []

  [top_pipe_1]
    type = FlowChannel1Phase
    position = '0 0 2'
    orientation = '1 0 0'
    length = 0.5
    n_elems = 10
    A = ${A_pipe}
    D_h = ${pipe_dia}
  []

  [top_pipe_2]
    type = FlowChannel1Phase
    position = '0.5 0 2'
    orientation = '1 0 0'
    length = 0.5
    n_elems = 10
    A = ${A_pipe}
    D_h = ${pipe_dia}
  []

  [jct4]
    type = VolumeJunction1Phase
    position = '0.5 0 2'
    volume = 1e-5
    connections = 'top_pipe_1:out top_pipe_2:in press_pipe:in'
    use_scalar_variables = false
  []

  [press_pipe]
    type = FlowChannel1Phase
    position = '0.5 0 2'
    orientation = '0 0 1'
    length = 0.2
    n_elems = 5
    A = ${A_pipe}
    D_h = ${pipe_dia}
  []

  [pressurizer]
    type = InletStagnationPressureTemperature1Phase
    p0 = ${press}
    T0 = ${T_in}
    input = press_pipe:out
  []

  [jct5]
    type = JunctionOneToOne1Phase
    connections = 'top_pipe_2:out down_pipe_1:in'
  []

  [down_pipe_1]
    type = FlowChannel1Phase
    position = '1 0 2'
    orientation = '0 0 -1'
    length = 0.25
    A = ${A_pipe}
    n_elems = 5
  []

  [jct6]
    type = JunctionOneToOne1Phase
    connections = 'down_pipe_1:out cooling_pipe:in'
  []

  [cooling_pipe]
    type = FlowChannel1Phase
    position = '1 0 1.75'
    orientation = '0 0 -1'
    length = 1.5
    n_elems = 25
    A = ${A_pipe}
  []

  [cold_wall]
    type = HeatTransferFromSpecifiedTemperature1Phase
    flow_channel = cooling_pipe
    T_wall = 300
    P_hf = '${fparse pi * pipe_dia}'
  []

  [jct7]
    type = JunctionOneToOne1Phase
    connections = 'cooling_pipe:out down_pipe_2:in'
  []

  [down_pipe_2]
    type = FlowChannel1Phase
    position = '1 0 0.25'
    orientation = '0 0 -1'
    length = 0.25
    n_elems = 10
    A = ${A_pipe}
    D_h = ${pipe_dia}
  []

  [jct8]
    type = JunctionOneToOne1Phase
    connections = 'down_pipe_2:out bottom_1:in'
  []

  [bottom_1]
    type = FlowChannel1Phase
    position = '1 0 0'
    orientation = '-1 0 0'
    length = 0.5
    n_elems = 5
    A = ${A_pipe}
    D_h = ${pipe_dia}
  []

  [pump]
    type = Pump1Phase
    position = '0.5 0 0'
    connections = 'bottom_1:out bottom_2:in'
    volume = 1e-4
    A_ref = ${A_pipe}
    head = 0
    use_scalar_variables = false
  []

  [bottom_2]
    type = FlowChannel1Phase
    position = '0.5 0 0'
    orientation = '-1 0 0'
    length = 0.5
    n_elems = 5
    A = ${A_pipe}
    D_h = ${pipe_dia}
  []

  [jct10]
    type = JunctionOneToOne1Phase
    connections = 'bottom_2:out up_pipe_1:in'
  []
[]

[ControlLogic]
  [set_point]
    type = GetFunctionValueControl
    function = ${m_dot_in}
  []

  [pid]
    type = PIDControl
    initial_value = 0
    set_point = set_point:value
    input = m_dot_pump
    K_p = 1.
    K_i = 4.
    K_d = 0
  []

  [set_pump_head]
    type = SetComponentRealValueControl
    component = pump
    parameter = head
    value = pid:output
  []
[]

[Postprocessors]
  [power_to_coolant]
    type = ADHeatRateConvection1Phase
    block = core_chan
    P_hf = '${fparse pi *core_dia}'
  []

  [m_dot_pump]
    type = ADFlowJunctionFlux1Phase
    boundary = core_chan:in
    connection_index = 1
    equation = mass
    junction = jct7
  []

  [core_T_out]
    type = SideAverageValue
    boundary = core_chan:out
    variable = T
  []

  [core_p_in]
    type = SideAverageValue
    boundary = core_chan:in
    variable = p
  []

  [core_p_out]
    type = SideAverageValue
    boundary = core_chan:out
    variable = p
  []

  [core_delta_p]
    type = ParsedPostprocessor
    pp_names = 'core_p_in core_p_out'
    expression = 'core_p_in - core_p_out'
  []

  [hx_pri_T_out]
    type = SideAverageValue
    boundary = cooling_pipe:out
    variable = T
  []
  [pump_head]
    type = RealComponentParameterValuePostprocessor
    component = pump
    parameter = head
  []
[]

[Preconditioning]
  [pc]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  start_time = 0

  [TimeStepper]
    type = IterationAdaptiveDT
    dt = 1
  []
  dtmax = 5
  end_time = 500

  line_search = basic
  solve_type = NEWTON

  petsc_options_iname = '-pc_type'
  petsc_options_value = 'lu'

  nl_rel_tol = 0
  nl_abs_tol = 1e-8
  nl_max_its = 25

[]

[Outputs]
  exodus = true

  [console]
    type = Console
    max_rows = 1
    outlier_variable_norms = false
  []
  print_linear_residuals = false
[]

(modules/thermal_hydraulics/test/tests/components/pump_1phase/pump_loop.i)

[GlobalParams]
  initial_T = 300
  initial_p = 1e5
  initial_vel = 0

  initial_vel_x = 0
  initial_vel_y = 0
  initial_vel_z = 0

  scaling_factor_1phase = '1 1 1'
  scaling_factor_rhoV  = 1
  scaling_factor_rhouV = 1
  scaling_factor_rhovV = 1
  scaling_factor_rhowV = 1
  scaling_factor_rhoEV = 1

  closures = simple_closures
[]

[FluidProperties]
  [fp]
    type = StiffenedGasFluidProperties
    gamma = 2.35
    q = -1167e3
    q_prime = 0
    p_inf = 1.e9
    cv = 1816
  []
[]

[Closures]
  [simple_closures]
    type = Closures1PhaseSimple
  []
[]

[Components]
  [pipe1a]
    type = FlowChannel1Phase
    fp = fp
    position = '0 0 0'
    orientation = '1 0 0'
    A = 0.785398163e-4    #1.0 cm (0.01 m) in diameter, A = 1/4 * PI * d^2
    D_h = 0.01
    f = 0.01
    length = 0.5
    n_elems = 2
  []

  [pipe1b]
    type = FlowChannel1Phase
    fp = fp
    position = '0.5 0 0'
    orientation = '1 0 0'
    A = 0.785398163e-4    #1.0 cm (0.01 m) in diameter, A = 1/4 * PI * d^2
    D_h = 0.01
    f = 0.01
    length = 0.5
    n_elems = 2
  []

  [pipe2]
    type = FlowChannel1Phase
    fp = fp
    position = '1 0 0'
    orientation = '0 1 0'
    A = 0.785398163e-4    #1.0 cm (0.01 m) in diameter, A = 1/4 * PI * d^2
    D_h = 0.01
    f = 0.01
    length = 1
    n_elems = 3
  []

  [pipe3]
    type = FlowChannel1Phase
    fp = fp
    position = '1 1 0'
    orientation = '-1 0 0'
    A = 0.785398163e-4    #1.0 cm (0.01 m) in diameter, A = 1/4 * PI * d^2
    D_h = 0.01
    f = 0.01
    length = 1
    n_elems = 3
  []

  [pipe4]
    type = FlowChannel1Phase
    fp = fp
    position = '0 1 0'
    orientation = '0 -1 0'
    A = 0.785398163e-4    #1.0 cm (0.01 m) in diameter, A = 1/4 * PI * d^2
    D_h = 0.01
    f = 0.01
    length = 1
    n_elems = 3
  []

  [pipe5]
    type = FlowChannel1Phase
    fp = fp
    position = '1 1 0'
    orientation = '0 1 0'
    A = 0.785398163e-4    #1.0 cm (0.01 m) in diameter, A = 1/4 * PI * d^2
    D_h = 0.01
    f = 0.01
    length = 0.5
    n_elems = 3
  []

  [pump]
    type = Pump1Phase
    connections = 'pipe1a:out pipe1b:in'
    head = 1.0
    position = '0.5 0 0'
    volume = 0.785398163e-3
    A_ref = 0.785398163e-4
    use_scalar_variables = false
  []

  [junction1]
    type = VolumeJunction1Phase
    connections = 'pipe1b:out pipe2:in'
    volume = 0.785398163e-3
    position = '1 0 0'
    use_scalar_variables = false
  []

  [junction2]
    type = VolumeJunction1Phase
    connections = 'pipe2:out pipe3:in pipe5:in'
    volume = 0.785398163e-3
    position = '1 1 0'
    use_scalar_variables = false
  []

  [junction3]
    type = VolumeJunction1Phase
    connections = 'pipe3:out pipe4:in'
    volume = 0.785398163e-3
    position = '0 1 0'
    use_scalar_variables = false
  []

  [junction4]
    type = VolumeJunction1Phase
    connections = 'pipe4:out pipe1a:in'
    volume = 0.785398163e-3
    position = '0 0 0'
    use_scalar_variables = false
  []

  [outlet]
    type = InletStagnationPressureTemperature1Phase
    input = 'pipe5:out'
    p0 = 1.e5
    T0 = 300
  []
[]

[Preconditioning]
  [SMP_PJFNK]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  scheme = 'bdf2'

  start_time = 0
  num_steps = 10
  dt = 1
  abort_on_solve_fail = true

  solve_type = 'PJFNK'
  line_search = 'basic'

  nl_rel_tol = 1e-6
  nl_abs_tol = 1e-7
  nl_max_its = 10

  l_tol = 1e-3
  l_max_its = 100

  petsc_options_iname = '-pc_type'
  petsc_options_value = 'lu'

  [Quadrature]
    type = gauss
    order = second
  []
[]

[Outputs]
  [out]
    type = Exodus
    show = 'rhouA p'
    execute_on = 'initial final'
  []
[]

(modules/thermal_hydraulics/test/tests/components/gate_valve_1phase/gate_valve_1phase.i)

# This input file is used to test the gate valve component.

# This problem consists of a T junction of 3 pipes. The inlet pipe is one of the
# 2 pipes of the "top" of the T. The other 2 pipes each have a gate valve.
# Initially, one of the 2 outlet pipes has an open valve and the other has a
# closed valve. Later in the transient, the valves gradually open/close to switch
# the outlet flow direction.

p = 1.0e5
T = 300.0
rho = 1.161430436 # @ 1e5 Pa, 300 K

D = 0.1
A = ${fparse pi * D^2 / 4.0}
V_junction = ${fparse pi * D^3 / 4.0}

vel_in = 2.0
m_dot = ${fparse rho * vel_in * A}

t_begin = 0.3
delta_t_open = 0.1

[GlobalParams]
  gravity_vector = '0 0 0'

  closures = simple_closures
  fp = fp

  f = 0.0

  initial_T = ${T}
  initial_p = ${p}
  initial_vel = 0
[]

[FluidProperties]
  [fp]
    type = IdealGasFluidProperties
    gamma = 1.4
    molar_mass = 0.02897
  []
[]

[Closures]
  [simple_closures]
    type = Closures1PhaseSimple
  []
[]

[Functions]
  [pipe3_open_fn]
    type = TimeRampFunction
    initial_value = 1
    final_value = 0
    initial_time = ${t_begin}
    ramp_duration = ${delta_t_open}
  []
  [pipe2_open_fn]
    type = ParsedFunction
    expression = '1 - pipe3_phi'
    symbol_names = 'pipe3_phi'
    symbol_values = 'pipe3_open_fn'
  []
[]

[Components]
  [inlet]
    type = InletMassFlowRateTemperature1Phase
    input = 'pipe1:in'
    m_dot = ${m_dot}
    T = ${T}
  []

  [pipe1]
    type = FlowChannel1Phase
    position = '0 0 0'
    orientation = '1 0 0'
    length = 1.0
    n_elems = 50
    A = ${A}
  []

  [volume_junction]
    type = VolumeJunction1Phase
    position = '1 0 0'
    connections = 'pipe1:out pipe2A:in pipe3A:in'
    volume = ${V_junction}
    initial_vel_x = 0
    initial_vel_y = 0
    initial_vel_z = 0
    use_scalar_variables = false
  []

  [pipe2A]
    type = FlowChannel1Phase
    position = '1 0 0'
    orientation = '0 1 0'
    length = 0.5
    n_elems = 25
    A = ${A}
  []

  [pipe2_valve]
    type = GateValve1Phase
    connections = 'pipe2A:out pipe2B:in'
    open_area_fraction = 0 # (controlled via 'pipe2_valve_control')
  []

  [pipe2B]
    type = FlowChannel1Phase
    position = '1 0.5 0'
    orientation = '0 1 0'
    length = 0.5
    n_elems = 25
    A = ${A}
  []

  [pipe2_outlet]
    type = Outlet1Phase
    input = 'pipe2B:out'
    p = ${p}
  []

  [pipe3A]
    type = FlowChannel1Phase
    position = '1 0 0'
    orientation = '1 0 0'
    length = 0.5
    n_elems = 25
    A = ${A}
  []

  [pipe3_valve]
    type = GateValve1Phase
    connections = 'pipe3A:out pipe3B:in'
    open_area_fraction = 0 # (controlled via 'pipe3_valve_control')
  []

  [pipe3B]
    type = FlowChannel1Phase
    position = '1.5 0 0'
    orientation = '1 0 0'
    length = 0.5
    n_elems = 25
    A = ${A}
  []

  [pipe3_outlet]
    type = Outlet1Phase
    input = 'pipe3B:out'
    p = ${p}
  []
[]

[ControlLogic]
  [pipe2_valve_control]
    type = TimeFunctionComponentControl
    component = pipe2_valve
    parameter = open_area_fraction
    function = pipe2_open_fn
  []
  [pipe3_valve_control]
    type = TimeFunctionComponentControl
    component = pipe3_valve
    parameter = open_area_fraction
    function = pipe3_open_fn
  []
[]

[Preconditioning]
  [smp]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  scheme = bdf2

  solve_type = PJFNK
  nl_rel_tol = 1e-8
  nl_abs_tol = 1e-8
  nl_max_its = 20

  l_tol = 1e-4

  start_time = 0.0
  end_time = 1.0
  dt = 0.01
  abort_on_solve_fail = true
[]

[Outputs]
  exodus = true
  show = 'p T vel'
  velocity_as_vector = false
  print_linear_residuals = false
  [console]
    type = Console
    max_rows = 1
  []
[]

(modules/thermal_hydraulics/test/tests/misc/initial_from_file/volume_junction/base.i)

[GlobalParams]
  scaling_factor_1phase = '1. 1.e-2 1.e-4'
  closures = simple_closures
[]

[FluidProperties]
  [fp]
    type = StiffenedGasFluidProperties
    gamma = 2.35
    cv = 1816.0
    q = -1.167e6
    p_inf = 1.0e9
    q_prime = 0
    k = 0.5
    mu = 281.8e-6
  []
[]

[Closures]
  [simple_closures]
    type = Closures1PhaseSimple
  []
[]

[Components]
  [pipe1]
    type = FlowChannel1Phase
    fp = fp
    # geometry
    position = '0 0 0'
    orientation = '1 0 0'
    length = 1
    n_elems = 3
    A = 1.907720E-04
    D_h = 1.698566E-02
    f = 0.1
  []

  [junction]
    type = VolumeJunction1Phase
    connections = 'pipe1:out pipe2:in'
    volume = 1
    position = '1 0 0'

    scaling_factor_rhoV  = 1
    scaling_factor_rhouV = 1
    scaling_factor_rhovV = 1
    scaling_factor_rhowV = 1
    scaling_factor_rhoEV = 1e-4

    use_scalar_variables = false
  []

  [pipe2]
    type = FlowChannel1Phase
    fp = fp
    # geometry
    position = '1 0 0'
    orientation = '1 0 0'
    length = 1
    n_elems = 3
    A = 1.907720E-04
    D_h = 1.698566E-02
    f = 0.1
  []

  [inlet]
    type = InletMassFlowRateTemperature1Phase
    input = 'pipe1:in'
    m_dot = 0.1
    T = 500
  []
  [outlet]
    type = Outlet1Phase
    input = 'pipe2:out'
    p = 6e6
  []
[]

[Preconditioning]
  [pc]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  scheme = 'bdf2'

  start_time = 0
  dt = 1
  abort_on_solve_fail = true

  solve_type = 'NEWTON'
  nl_rel_tol = 0
  nl_abs_tol = 1e-10
  nl_max_its = 10

  l_tol = 1e-3
  l_max_its = 100

  petsc_options_iname = '-pc_type'
  petsc_options_value = 'lu'
[]

[Outputs]
  exodus = true
  velocity_as_vector = false
[]

(modules/thermal_hydraulics/test/tests/components/volume_junction_1phase/phy.shower.i)

# This problem models a "shower": water from two pipes, one hot and one cold,
# mixes together to produce a temperature between the two.

[GlobalParams]
  gravity_vector = '0 0 0'

  initial_T = 300
  initial_p = 1e5
  initial_vel = 0
  initial_vel_x = 0
  initial_vel_y = 0
  initial_vel_z = 0

  # global parameters for pipes
  fp = eos
  orientation = '1 0 0'
  length = 1
  n_elems = 20
  f = 0

  scaling_factor_1phase = '1 1 1e-6'

  closures = simple_closures
[]

[FluidProperties]
  [eos]
    type = StiffenedGasFluidProperties
    gamma = 2.35
    cv = 1816.0
    q = -1.167e6
    p_inf = 1.0e9
    q_prime = 0
  []
[]

[Closures]
  [simple_closures]
    type = Closures1PhaseSimple
  []
[]

[Components]
  [inlet_hot]
    type = InletDensityVelocity1Phase
    input = 'pipe_hot:in'
    # rho @ (p = 1e5, T = 310 K)
    rho = 1315.9279785683
    vel = 1
  []
  [inlet_cold]
    type = InletDensityVelocity1Phase
    input = 'pipe_cold:in'
    # rho @ (p = 1e5, T = 280 K)
    rho = 1456.9202619863
    vel = 1
  []
  [outlet]
    type = Outlet1Phase
    input = 'pipe_warm:out'
    p = 1e5
  []

  [pipe_hot]
    type = FlowChannel1Phase
    position = '0 1 0'
    A = 1
  []
  [pipe_cold]
    type = FlowChannel1Phase
    position = '0 0 0'
    A = 1
  []
  [pipe_warm]
    type = FlowChannel1Phase
    position = '1 0.5 0'
    A = 2
  []

  [junction]
    type = VolumeJunction1Phase
    connections = 'pipe_cold:out pipe_hot:out pipe_warm:in'
    position = '1 0.5 0'
    volume = 1e-8
    use_scalar_variables = false
  []
[]

[Preconditioning]
  [pc]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  scheme = 'bdf2'

  solve_type = 'NEWTON'
  line_search = 'basic'
  nl_rel_tol = 1e-8
  nl_abs_tol = 1e-5
  nl_max_its = 10

  l_tol = 1e-2
  l_max_its = 10

  start_time = 0
  end_time = 5
  dt = 0.05

  # abort_on_solve_fail = true
[]

[Postprocessors]
  # These post-processors are used to test that the energy flux on
  # the warm side of the junction is equal to the sum of the energy
  # fluxes of the hot and cold inlets to the junction.
  [energy_flux_hot]
    type = EnergyFluxIntegral
    boundary = pipe_hot:out
    arhouA = rhouA
    H = H
  []
  [energy_flux_cold]
    type = EnergyFluxIntegral
    boundary = pipe_cold:out
    arhouA = rhouA
    H = H
  []
  [energy_flux_warm]
    type = EnergyFluxIntegral
    boundary = pipe_warm:in
    arhouA = rhouA
    H = H
  []
  [energy_flux_inlet_sum]
    type = SumPostprocessor
    values = 'energy_flux_hot energy_flux_cold'
  []
  [test_rel_err]
    type = RelativeDifferencePostprocessor
    value1 = energy_flux_warm
    value2 = energy_flux_inlet_sum
  []
[]

[Outputs]
  [out]
    type = CSV
    show = test_rel_err
    sync_only = true
    sync_times = '3 4 5'
  []
  [console]
    type = Console
    max_rows = 1
  []
  print_linear_residuals = false
[]

(modules/thermal_hydraulics/test/tests/misc/uniform_refine/test.i)

[GlobalParams]
  gravity_vector = '0 0 0'

  initial_p = 1e5
  initial_T = 300
  initial_vel = 0

  closures = simple_closures

  rdg_slope_reconstruction = FULL
  f = 0
  fp = eos
[]

[FluidProperties]
  [eos]
    type = StiffenedGasFluidProperties
    gamma = 2.35
    q = -1167e3
    q_prime = 0
    p_inf = 1.e9
    cv = 1816
  []
[]

[Closures]
  [simple_closures]
    type = Closures1PhaseSimple
  []
[]

[SolidProperties]
  [mat1]
    type = ThermalFunctionSolidProperties
    rho = 10
    cp = 1
    k = 1
  []
[]

[Components]
  [pipe1]
    type = FlowChannel1Phase
    position = '0 0 0'
    orientation = '1 0 0'
    length = 1
    n_elems = 2
    A = 1
  []

  [pipe2]
    type = FlowChannel1Phase
    position = '1 0 0'
    orientation = '1 0 0'
    length = 1
    n_elems = 3
    A = 1
  []

  [junction]
    type = VolumeJunction1Phase
    connections = 'pipe1:out pipe2:in'
    volume = 1e-5
    position = '1 0 0'

    initial_vel_x = 0
    initial_vel_y = 0
    initial_vel_z = 0

    use_scalar_variables = false
  []

  [inlet]
    type = SolidWall1Phase
    input = 'pipe1:in'
  []

  [outlet]
    type = SolidWall1Phase
    input = 'pipe2:out'
  []

  [hs]
    type = HeatStructureCylindrical
    position = '0 1 0'
    orientation = '1 0 0'
    length = '1'
    n_elems = '2'
    names = '0'
    widths = 0.5
    n_part_elems = '1'
    solid_properties = 'mat1'
    solid_properties_T_ref = '300'
  []
[]

[Preconditioning]
  [pc]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient

  start_time = 0
  dt = 1e-4
  num_steps = 1
  abort_on_solve_fail = true

  solve_type = 'NEWTON'
  nl_rel_tol = 1e-5
  nl_abs_tol = 1e-7
  nl_max_its = 10

  l_tol = 1e-3
  l_max_its = 10

  automatic_scaling = true
[]

[Outputs]
  exodus = true
  show = 'A'
[]

[Debug]
  show_actions = true
[]

(modules/thermal_hydraulics/include/components/JunctionParallelChannels1Phase.h)

// This file is part of the MOOSE framework
// https://www.mooseframework.org
//
// All rights reserved, see COPYRIGHT for full restrictions
// https://github.com/idaholab/moose/blob/master/COPYRIGHT
//
// Licensed under LGPL 2.1, please see LICENSE for details
// https://www.gnu.org/licenses/lgpl-2.1.html

#pragma once

#include "VolumeJunction1Phase.h"

/**
 * Junction between 1-phase flow channels that are parallel
 */
class JunctionParallelChannels1Phase : public VolumeJunction1Phase
{
public:
  JunctionParallelChannels1Phase(const InputParameters & params);

protected:
  /**
   * Builds user object for computing and storing the fluxes
   */
  virtual void buildVolumeJunctionUserObject() override;

public:
  static InputParameters validParams();
};

(modules/thermal_hydraulics/include/components/ShaftConnectedCompressor1Phase.h)

// This file is part of the MOOSE framework
// https://www.mooseframework.org
//
// All rights reserved, see COPYRIGHT for full restrictions
// https://github.com/idaholab/moose/blob/master/COPYRIGHT
//
// Licensed under LGPL 2.1, please see LICENSE for details
// https://www.gnu.org/licenses/lgpl-2.1.html

#pragma once

#include "VolumeJunction1Phase.h"
#include "ShaftConnectable.h"

/**
 * 1-phase compressor that must be connected to a Shaft component
 */
class ShaftConnectedCompressor1Phase : public VolumeJunction1Phase, public ShaftConnectable
{
public:
  ShaftConnectedCompressor1Phase(const InputParameters & params);

  virtual void addVariables() override;
  virtual void addMooseObjects() override;
  virtual UserObjectName getShaftConnectedUserObjectName() const override
  {
    return _junction_uo_name;
  }

protected:
  virtual void check() const override;
  virtual void buildVolumeJunctionUserObject() override;

  /// Compressor inlet
  const BoundaryName & _inlet;
  /// Compressor outlet
  const BoundaryName & _outlet;
  /// Rated compressor speed
  const Real & _omega_rated;
  /// Rated compressor mass flow rate
  const Real & _mdot_rated;
  /// Rated compressor inlet stagnation fluid density
  const Real & _rho0_rated;
  /// Rated compressor inlet stagnation sound speed
  const Real & _c0_rated;
  /// Compressor speed threshold for friction
  const Real & _speed_cr_fr;
  /// Compressor friction constant
  const Real & _tau_fr_const;
  /// Compressor friction coefficients
  const std::vector<Real> & _tau_fr_coeff;
  /// Compressor speed threshold for inertia
  const Real & _speed_cr_I;
  /// Compressor inertia constant
  const Real & _inertia_const;
  /// Compressor inertia coefficients
  const std::vector<Real> & _inertia_coeff;

  /// Compressor speeds which correspond to Rp and eff function order
  const std::vector<Real> & _speeds;
  /// Names of the pressure ratio functions
  const std::vector<FunctionName> & _Rp_functions;
  /// Names of the adiabatic efficiency functions
  const std::vector<FunctionName> & _eff_functions;
  /// Name of compressor delta_p variable
  const VariableName _delta_p_var_name;
  /// Name of compressor isentropic torque variable
  const VariableName _isentropic_torque_var_name;
  /// Name of compressor dissipation torque variable
  const VariableName _dissipation_torque_var_name;
  /// Name of compressor friction torque variable
  const VariableName _friction_torque_var_name;
  /// Name of compressor inertia variable
  const VariableName _moi_var_name;

public:
  static InputParameters validParams();
};

(modules/thermal_hydraulics/include/components/ShaftConnectedTurbine1Phase.h)

// This file is part of the MOOSE framework
// https://www.mooseframework.org
//
// All rights reserved, see COPYRIGHT for full restrictions
// https://github.com/idaholab/moose/blob/master/COPYRIGHT
//
// Licensed under LGPL 2.1, please see LICENSE for details
// https://www.gnu.org/licenses/lgpl-2.1.html

#pragma once

#include "VolumeJunction1Phase.h"
#include "ShaftConnectable.h"

/**
 * 1-phase turbine that must be connected to a Shaft component
 */
class ShaftConnectedTurbine1Phase : public VolumeJunction1Phase, public ShaftConnectable
{
public:
  ShaftConnectedTurbine1Phase(const InputParameters & params);

  virtual void addVariables() override;
  virtual void addMooseObjects() override;
  virtual UserObjectName getShaftConnectedUserObjectName() const override
  {
    return _junction_uo_name;
  }

protected:
  virtual void check() const override;
  virtual void buildVolumeJunctionUserObject() override;

  /// Turbine inlet
  const BoundaryName & _inlet;
  /// Turbine outlet
  const BoundaryName & _outlet;
  /// Rated turbine speed
  const Real & _omega_rated;
  /// Turbine wheel diameter
  const Real & _D_wheel;
  /// Turbine speed threshold for friction
  const Real & _speed_cr_fr;
  /// Turbine friction constant
  const Real & _tau_fr_const;
  /// Turbine friction coefficients
  const std::vector<Real> & _tau_fr_coeff;
  /// Turbine speed threshold for inertia
  const Real & _speed_cr_I;
  /// Turbine inertia constant
  const Real & _inertia_const;
  /// Turbine inertia coefficients
  const std::vector<Real> & _inertia_coeff;

  /// Name of function to compute data for turbine head
  const FunctionName & _head_coefficient;
  /// Name of function to compute data for turbine power
  const FunctionName & _power_coefficient;
  /// Name of turbine pressure drop variable
  const VariableName _delta_p_var_name;
  /// Name of turbine power variable
  const VariableName _power_var_name;
  /// Name of turbine driving torque variable
  const VariableName _driving_torque_var_name;
  /// Name of turbine friction torque variable
  const VariableName _friction_torque_var_name;
  /// Name of turbine flow_coeff torque variable
  const VariableName _flow_coeff_var_name;
  /// Name of turbine inertia variable
  const VariableName _moi_var_name;

public:
  static InputParameters validParams();
};

(modules/thermal_hydraulics/include/components/ShaftConnectedPump1Phase.h)

// This file is part of the MOOSE framework
// https://www.mooseframework.org
//
// All rights reserved, see COPYRIGHT for full restrictions
// https://github.com/idaholab/moose/blob/master/COPYRIGHT
//
// Licensed under LGPL 2.1, please see LICENSE for details
// https://www.gnu.org/licenses/lgpl-2.1.html

#pragma once

#include "VolumeJunction1Phase.h"
#include "ShaftConnectable.h"

/**
 * 1-phase pump that must be connected to a Shaft component
 */
class ShaftConnectedPump1Phase : public VolumeJunction1Phase, public ShaftConnectable
{
public:
  ShaftConnectedPump1Phase(const InputParameters & params);

  virtual void addVariables() override;
  virtual void addMooseObjects() override;
  virtual UserObjectName getShaftConnectedUserObjectName() const override
  {
    return _junction_uo_name;
  }

protected:
  virtual void check() const override;
  virtual void buildVolumeJunctionUserObject() override;

  /// Pump inlet
  const BoundaryName & _inlet;
  /// Pump outlet
  const BoundaryName & _outlet;
  /// Rated pump speed
  const Real & _omega_rated;
  /// Rated pump volumetric flow rate
  const Real & _volumetric_rated;
  /// Rated pump head
  const Real & _head_rated;
  /// Rated pump torque
  const Real & _torque_rated;
  /// Rated pump density
  const Real & _density_rated;
  /// Pump speed threshold for friction
  const Real & _speed_cr_fr;
  /// Pump friction constant
  const Real & _tau_fr_const;
  /// Pump friction coefficients
  const std::vector<Real> & _tau_fr_coeff;
  /// Pump speed threshold for inertia
  const Real & _speed_cr_I;
  /// Pump inertia constant
  const Real & _inertia_const;
  /// Pump inertia coefficients
  const std::vector<Real> & _inertia_coeff;
  /// Name of function to compute data for pump head
  const FunctionName & _head;
  /// Name of function to compute data for pump torque
  const FunctionName & _torque_hydraulic;
  /// Name of pump head variable
  const VariableName _head_var_name;
  /// Name of pump hydraulic torque variable
  const VariableName _hydraulic_torque_var_name;
  /// Name of pump friction torque variable
  const VariableName _friction_torque_var_name;
  /// Name of pump inertia variable
  const VariableName _moi_var_name;
  /// Transition width for the sign of the frictional torque when speed is 0
  const Real & _transition_width;

public:
  static InputParameters validParams();
};

(modules/thermal_hydraulics/include/components/Pump1Phase.h)

// This file is part of the MOOSE framework
// https://www.mooseframework.org
//
// All rights reserved, see COPYRIGHT for full restrictions
// https://github.com/idaholab/moose/blob/master/COPYRIGHT
//
// Licensed under LGPL 2.1, please see LICENSE for details
// https://www.gnu.org/licenses/lgpl-2.1.html

#pragma once

#include "VolumeJunction1Phase.h"

/**
 * Pump between 1-phase flow channels that has a non-zero volume
 */
class Pump1Phase : public VolumeJunction1Phase
{
public:
  Pump1Phase(const InputParameters & params);

protected:
  virtual void buildVolumeJunctionUserObject() override;

  /// Pump head [m]
  const Real & _head;

public:
  static InputParameters validParams();
};

Formulation
Usage
Input Parameters
Input Files
Child Objects
References