TimeRampFunction

Ramps up to a value from another value over time.

Input Parameters

final_valueFinal value
C++ Type:double
Controllable:No
Description:Final value
initial_valueInitial value
C++ Type:double
Controllable:No
Description:Initial value
ramp_durationDuration, in seconds, of the ramp
C++ Type:double
Controllable:No
Description:Duration, in seconds, of the ramp

Required Parameters

execute_onLINEARThe list of flag(s) indicating when this object should be executed, the available options include FORWARD, ADJOINT, HOMOGENEOUS_FORWARD, ADJOINT_TIMESTEP_BEGIN, ADJOINT_TIMESTEP_END, NONE, INITIAL, LINEAR, NONLINEAR, TIMESTEP_END, TIMESTEP_BEGIN, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, FINAL, CUSTOM, ALWAYS.
Default:LINEAR
C++ Type:ExecFlagEnum
Options:FORWARD, ADJOINT, HOMOGENEOUS_FORWARD, ADJOINT_TIMESTEP_BEGIN, ADJOINT_TIMESTEP_END, NONE, INITIAL, LINEAR, NONLINEAR, TIMESTEP_END, TIMESTEP_BEGIN, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, FINAL, CUSTOM, ALWAYS
Controllable:No
Description:The list of flag(s) indicating when this object should be executed, the available options include FORWARD, ADJOINT, HOMOGENEOUS_FORWARD, ADJOINT_TIMESTEP_BEGIN, ADJOINT_TIMESTEP_END, NONE, INITIAL, LINEAR, NONLINEAR, TIMESTEP_END, TIMESTEP_BEGIN, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, FINAL, CUSTOM, ALWAYS.
initial_time0Initial time (necessary if not equal to zero)
Default:0
C++ Type:double
Controllable:No
Description:Initial time (necessary if not equal to zero)

Optional Parameters

control_tagsAdds user-defined labels for accessing object parameters via control logic.
C++ Type:std::vector<std::string>
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
Controllable:No
Description:Set the enabled status of the MooseObject.

Advanced Parameters

Input Files

(modules/thermal_hydraulics/test/tests/components/gate_valve_1phase/gate_valve_1phase.i)
(modules/thermal_hydraulics/test/tests/components/volume_junction_1phase/phy.form_loss.i)

References

No citations exist within this document.

(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
  []

  [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/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
  []

  [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
[]

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

Input Parameters
Input Files
References