QuadSubChannel1PhaseProblem

Solver class for subchannels in a square lattice assembly and bare fuel pins

Overview

This class solves for the subchannel flow variables in the case of subchannels/pins arranged in a square lattice. It inherits from the base class : SubChannel1PhaseProblem. Information regarding the solver can be found in SubChannel Theory.

Pin surface temperature is calculated at the end of the solve, if there is a PinMesh using Dittus Boelter correlation.

Example Input File Syntax

[SubChannel]
  type = QuadSubChannel1PhaseProblem
  fp = water
  n_blocks = 1
  beta = 0.006
  CT = 2.6
  compute_density = true
  compute_viscosity = true
  compute_power = true
  P_out = ${P_out}
  verbose_subchannel = true
  implicit = true
  segregated = true
[]

Input Parameters

CTTurbulent modeling parameter
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Turbulent modeling parameter
P_outThe postprocessor (or scalar) that provides the value of outlet pressure [Pa]
C++ Type:PostprocessorName
Unit:(no unit assumed)
Controllable:No
Description:The postprocessor (or scalar) that provides the value of outlet pressure [Pa]
betaThermal diffusion coefficient used in turbulent crossflow.
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Thermal diffusion coefficient used in turbulent crossflow.
compute_densityFalseFlag that enables the calculation of density
Default:False
C++ Type:bool
Controllable:No
Description:Flag that enables the calculation of density
compute_powerFalseFlag that informs whether we solve the Enthalpy/Temperature equations or not
Default:False
C++ Type:bool
Controllable:No
Description:Flag that informs whether we solve the Enthalpy/Temperature equations or not
compute_viscosityFalseFlag that enables the calculation of viscosity
Default:False
C++ Type:bool
Controllable:No
Description:Flag that enables the calculation of viscosity
fpFluid properties user object name
C++ Type:UserObjectName
Controllable:No
Description:Fluid properties user object name
n_blocksThe number of blocks in the axial direction
C++ Type:unsigned int
Controllable:No
Description:The number of blocks in the axial direction

Required Parameters

P_tol1e-06Pressure tolerance
Default:1e-06
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Pressure tolerance
T_maxit100Maximum number of iterations for inner temperature loop
Default:100
C++ Type:int
Controllable:No
Description:Maximum number of iterations for inner temperature loop
T_tol1e-06Temperature tolerance
Default:1e-06
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Temperature tolerance
atol1e-06Absolute tolerance for ksp solver
Default:1e-06
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Absolute tolerance for ksp solver
constant_betaTrueBoolean to define the use of a constant beta or beta correlation (Kim and Chung, 2001)
Default:True
C++ Type:bool
Controllable:No
Description:Boolean to define the use of a constant beta or beta correlation (Kim and Chung, 2001)
default_friction_modelTrueBoolean to define which friction model to use (default: Pang, B. et al. KIT, 2013. / non-default: Todreas-Kazimi NUCLEAR SYSTEMS, second edition, Volume 1, 2011)
Default:True
C++ Type:bool
Controllable:No
Description:Boolean to define which friction model to use (default: Pang, B. et al. KIT, 2013. / non-default: Todreas-Kazimi NUCLEAR SYSTEMS, second edition, Volume 1, 2011)
deformationFalseBoolean that activates the deformation effect based on values for: displacement, Dpin
Default:False
C++ Type:bool
Controllable:No
Description:Boolean that activates the deformation effect based on values for: displacement, Dpin
dtol100000Divergence tolerance or ksp solver
Default:100000
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Divergence tolerance or ksp solver
implicitFalseBoolean to define the use of explicit or implicit solution.
Default:False
C++ Type:bool
Controllable:No
Description:Boolean to define the use of explicit or implicit solution.
interpolation_schemecentral_differenceInterpolation scheme used for the method. Default is central difference
Default:central_difference
C++ Type:MooseEnum
Options:upwind, downwind, central_difference, exponential
Controllable:No
Description:Interpolation scheme used for the method. Default is central difference
linear_sys_namesThe linear system names
C++ Type:std::vector<LinearSystemName>
Controllable:No
Description:The linear system names
maxit10000Maximum number of iterations for ksp solver
Default:10000
C++ Type:long
Controllable:No
Description:Maximum number of iterations for ksp solver
monolithic_thermalFalseBoolean to define whether to use thermal monolithic solve.
Default:False
C++ Type:bool
Controllable:No
Description:Boolean to define whether to use thermal monolithic solve.
regard_general_exceptions_as_errorsFalseIf we catch an exception during residual/Jacobian evaluaton for which we don't have specific handling, immediately error instead of allowing the time step to be cut
Default:False
C++ Type:bool
Controllable:No
Description:If we catch an exception during residual/Jacobian evaluaton for which we don't have specific handling, immediately error instead of allowing the time step to be cut
rtol1e-06Relative tolerance for ksp solver
Default:1e-06
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Relative tolerance for ksp solver
segregatedTrueBoolean to define whether to use a segregated solution.
Default:True
C++ Type:bool
Controllable:No
Description:Boolean to define whether to use a segregated solution.
solveTrueWhether or not to actually solve the Nonlinear system. This is handy in the case that all you want to do is execute AuxKernels, Transfers, etc. without actually solving anything
Default:True
C++ Type:bool
Controllable:Yes
Description:Whether or not to actually solve the Nonlinear system. This is handy in the case that all you want to do is execute AuxKernels, Transfers, etc. without actually solving anything
staggered_pressureFalseBoolean to define the use of explicit or implicit solution.
Default:False
C++ Type:bool
Controllable:No
Description:Boolean to define the use of explicit or implicit solution.
verbose_subchannelFalseBoolean to print out information related to subchannel solve.
Default:False
C++ Type:bool
Controllable:No
Description:Boolean to print out information related to subchannel solve.

Optional Parameters

allow_initial_conditions_with_restartFalseTrue to allow the user to specify initial conditions when restarting. Initial conditions can override any restarted field
Default:False
C++ Type:bool
Controllable:No
Description:True to allow the user to specify initial conditions when restarting. Initial conditions can override any restarted field
force_restartFalseEXPERIMENTAL: If true, a sub_app may use a restart file instead of using of using the master backup file
Default:False
C++ Type:bool
Controllable:No
Description:EXPERIMENTAL: If true, a sub_app may use a restart file instead of using of using the master backup file
restart_file_baseFile base name used for restart (e.g. / or /LATEST to grab the latest file available)
C++ Type:FileNameNoExtension
Controllable:No
Description:File base name used for restart (e.g. / or /LATEST to grab the latest file available)

Restart Parameters

allow_invalid_solutionFalseSet to true to allow convergence even though the solution has been marked as 'invalid'
Default:False
C++ Type:bool
Controllable:No
Description:Set to true to allow convergence even though the solution has been marked as 'invalid'
immediately_print_invalid_solutionFalseWhether or not to report invalid solution warnings at the time the warning is produced instead of after the calculation
Default:False
C++ Type:bool
Controllable:No
Description:Whether or not to report invalid solution warnings at the time the warning is produced instead of after the calculation
show_invalid_solution_consoleTrueSet to true to show the invalid solution occurance summary in console
Default:True
C++ Type:bool
Controllable:No
Description:Set to true to show the invalid solution occurance summary in console

Solution Validity Control Parameters

boundary_restricted_elem_integrity_checkTrueSet to false to disable checking of boundary restricted elemental object variable dependencies, e.g. are the variable dependencies defined on the selected boundaries?
Default:True
C++ Type:bool
Controllable:No
Description:Set to false to disable checking of boundary restricted elemental object variable dependencies, e.g. are the variable dependencies defined on the selected boundaries?
boundary_restricted_node_integrity_checkTrueSet to false to disable checking of boundary restricted nodal object variable dependencies, e.g. are the variable dependencies defined on the selected boundaries?
Default:True
C++ Type:bool
Controllable:No
Description:Set to false to disable checking of boundary restricted nodal object variable dependencies, e.g. are the variable dependencies defined on the selected boundaries?
check_uo_aux_stateFalseTrue to turn on a check that no state presents during the evaluation of user objects and aux kernels
Default:False
C++ Type:bool
Controllable:No
Description:True to turn on a check that no state presents during the evaluation of user objects and aux kernels
error_on_jacobian_nonzero_reallocationFalseThis causes PETSc to error if it had to reallocate memory in the Jacobian matrix due to not having enough nonzeros
Default:False
C++ Type:bool
Controllable:No
Description:This causes PETSc to error if it had to reallocate memory in the Jacobian matrix due to not having enough nonzeros
fv_bcs_integrity_checkTrueSet to false to disable checking of overlapping Dirichlet and Flux BCs and/or multiple DirichletBCs per sideset
Default:True
C++ Type:bool
Controllable:No
Description:Set to false to disable checking of overlapping Dirichlet and Flux BCs and/or multiple DirichletBCs per sideset
kernel_coverage_block_listList of subdomains for kernel coverage check. The meaning of this list is controlled by the parameter 'kernel_coverage_check' (whether this is the list of subdomains to be checked, not to be checked or not taken into account).
C++ Type:std::vector<SubdomainName>
Controllable:No
Description:List of subdomains for kernel coverage check. The meaning of this list is controlled by the parameter 'kernel_coverage_check' (whether this is the list of subdomains to be checked, not to be checked or not taken into account).
material_coverage_block_listList of subdomains for material coverage check. The meaning of this list is controlled by the parameter 'material_coverage_check' (whether this is the list of subdomains to be checked, not to be checked or not taken into account).
C++ Type:std::vector<SubdomainName>
Controllable:No
Description:List of subdomains for material coverage check. The meaning of this list is controlled by the parameter 'material_coverage_check' (whether this is the list of subdomains to be checked, not to be checked or not taken into account).
material_coverage_checkTRUEControls, if and how a material subdomain coverage check is performed. With 'TRUE' or 'ON' all subdomains are checked (the default). Setting 'FALSE' or 'OFF' will disable the check for all subdomains. To exclude a predefined set of subdomains 'SKIP_LIST' is to be used, while the subdomains to skip are to be defined in the parameter 'material_coverage_block_list'. To limit the check to a list of subdomains, 'ONLY_LIST' is to be used (again, using the parameter 'material_coverage_block_list').
Default:TRUE
C++ Type:MooseEnum
Options:FALSE, TRUE, OFF, ON, SKIP_LIST, ONLY_LIST
Controllable:No
Description:Controls, if and how a material subdomain coverage check is performed. With 'TRUE' or 'ON' all subdomains are checked (the default). Setting 'FALSE' or 'OFF' will disable the check for all subdomains. To exclude a predefined set of subdomains 'SKIP_LIST' is to be used, while the subdomains to skip are to be defined in the parameter 'material_coverage_block_list'. To limit the check to a list of subdomains, 'ONLY_LIST' is to be used (again, using the parameter 'material_coverage_block_list').
material_dependency_checkTrueSet to false to disable material dependency check
Default:True
C++ Type:bool
Controllable:No
Description:Set to false to disable material dependency check

Simulation Checks 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.
default_ghostingFalseWhether or not to use libMesh's default amount of algebraic and geometric ghosting
Default:False
C++ Type:bool
Controllable:No
Description:Whether or not to use libMesh's default amount of algebraic and geometric ghosting
enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Controllable:No
Description:Set the enabled status of the MooseObject.

Advanced Parameters

extra_tag_matricesExtra matrices to add to the system that can be filled by objects which compute residuals and Jacobians (Kernels, BCs, etc.) by setting tags on them. The outer index is for which nonlinear system the extra tag vectors should be added for
C++ Type:std::vector<std::vector<TagName>>
Controllable:No
Description:Extra matrices to add to the system that can be filled by objects which compute residuals and Jacobians (Kernels, BCs, etc.) by setting tags on them. The outer index is for which nonlinear system the extra tag vectors should be added for
extra_tag_solutionsExtra solution vectors to add to the system that can be used by objects for coupling variable values stored in them.
C++ Type:std::vector<TagName>
Controllable:No
Description:Extra solution vectors to add to the system that can be used by objects for coupling variable values stored in them.
extra_tag_vectorsExtra vectors to add to the system that can be filled by objects which compute residuals and Jacobians (Kernels, BCs, etc.) by setting tags on them. The outer index is for which nonlinear system the extra tag vectors should be added for
C++ Type:std::vector<std::vector<TagName>>
Controllable:No
Description:Extra vectors to add to the system that can be filled by objects which compute residuals and Jacobians (Kernels, BCs, etc.) by setting tags on them. The outer index is for which nonlinear system the extra tag vectors should be added for
not_zeroed_tag_vectorsExtra vector tags which the sytem will not zero when other vector tags are zeroed. The outer index is for which nonlinear system the extra tag vectors should be added for
C++ Type:std::vector<std::vector<TagName>>
Controllable:No
Description:Extra vector tags which the sytem will not zero when other vector tags are zeroed. The outer index is for which nonlinear system the extra tag vectors should be added for

Contribution To Tagged Field Data Parameters

identify_variable_groups_in_nlTrueWhether to identify variable groups in nonlinear systems. This affects dof ordering
Default:True
C++ Type:bool
Controllable:No
Description:Whether to identify variable groups in nonlinear systems. This affects dof ordering
restore_original_nonzero_patternFalseWhether we should reset matrix memory for every Jacobian evaluation. This option is useful if the sparsity pattern is constantly changing and you are using hash table assembly or if you wish to continually restore the matrix to the originally preallocated sparsity pattern computed by relationship managers.
Default:False
C++ Type:bool
Controllable:No
Description:Whether we should reset matrix memory for every Jacobian evaluation. This option is useful if the sparsity pattern is constantly changing and you are using hash table assembly or if you wish to continually restore the matrix to the originally preallocated sparsity pattern computed by relationship managers.
use_hash_table_matrix_assemblyFalseWhether to assemble matrices using hash tables instead of preallocating matrix memory. This can be a good option if the sparsity pattern changes throughout the course of the simulation.
Default:False
C++ Type:bool
Controllable:No
Description:Whether to assemble matrices using hash tables instead of preallocating matrix memory. This can be a good option if the sparsity pattern changes throughout the course of the simulation.

Nonlinear System(S) Parameters

near_null_space_dimension0The dimension of the near nullspace
Default:0
C++ Type:unsigned int
Controllable:No
Description:The dimension of the near nullspace
null_space_dimension0The dimension of the nullspace
Default:0
C++ Type:unsigned int
Controllable:No
Description:The dimension of the nullspace
transpose_null_space_dimension0The dimension of the transpose nullspace
Default:0
C++ Type:unsigned int
Controllable:No
Description:The dimension of the transpose nullspace

Null Space Removal Parameters

parallel_barrier_messagingFalseDisplays messaging from parallel barrier notifications when executing or transferring to/from Multiapps (default: false)
Default:False
C++ Type:bool
Controllable:No
Description:Displays messaging from parallel barrier notifications when executing or transferring to/from Multiapps (default: false)
verbose_multiappsFalseSet to True to enable verbose screen printing related to MultiApps
Default:False
C++ Type:bool
Controllable:No
Description:Set to True to enable verbose screen printing related to MultiApps
verbose_restoreFalseSet to True to enable verbose screen printing related to solution restoration
Default:False
C++ Type:bool
Controllable:No
Description:Set to True to enable verbose screen printing related to solution restoration
verbose_setupfalseSet to 'true' to have the problem report on any object created. Set to 'extra' to also display all parameters.
Default:false
C++ Type:MooseEnum
Options:false, true, extra
Controllable:No
Description:Set to 'true' to have the problem report on any object created. Set to 'extra' to also display all parameters.

Verbosity Parameters

Input Files

(modules/subchannel/test/tests/problems/psbt/psbt_implicit.i)
(modules/subchannel/validation/psbt/psbt_null_transient/psbt_ss.i)
(modules/subchannel/verification/friction_model_verification/two_channel2.i)
(modules/subchannel/examples/heating_test/3X3_channel.i)
(modules/subchannel/examples/mesh_generator/psbt_mesh_generator_test.i)
(modules/subchannel/validation/psbt/psbt_null_transient/psbt_transient.i)
(modules/subchannel/test/tests/problems/psbt/psbt_explicit_staggered.i)
(modules/subchannel/verification/enthalpy_mixing_verification/two_channel.i)
(modules/subchannel/test/tests/restart/transient.i)
(modules/subchannel/verification/friction_model_verification/two_channel.i)
(modules/subchannel/test/tests/problems/psbt/psbt_full_monolithic_staggered.i)
(modules/subchannel/validation/Blockage/PNNL_7x7/7X7blockage70.i)
(modules/subchannel/test/tests/restart/steady.i)
(modules/subchannel/validation/PNNL_12_pin/steady_state/2X6_ss.i)
(modules/subchannel/test/tests/problems/psbt/psbt_explicit.i)
(modules/subchannel/test/tests/problems/psbt/psbt_full_monolithic.i)
(modules/subchannel/test/tests/problems/coupling/main.i)
(modules/subchannel/test/tests/problems/psbt/psbt_monolithic.i)
(modules/subchannel/validation/PNNL_12_pin/transient/2X6_transient.i)
(modules/subchannel/test/tests/problems/psbt/psbt_explicit_v2.i)
(modules/subchannel/examples/coupling/thermo_mech/quad/one_pin_problem.i)
(modules/subchannel/validation/Blockage/PNNL_7x7/7X7blockage90.i)
(modules/subchannel/validation/psbt/psbt_ss/psbt.i)

(modules/subchannel/test/tests/problems/psbt/psbt_implicit.i)

T_in = 359.15
# [1e+6 kg/m^2-hour] turns into kg/m^2-sec
mass_flux_in = '${fparse 1e+6 * 17.00 / 3600.}'
P_out = 4.923e6 # Pa
pin_diameter = 0.00950

[QuadSubChannelMesh]
  [sub_channel]
    type = SCMQuadSubChannelMeshGenerator
    nx = 6
    ny = 6
    n_cells = 10
    pitch = 0.0126
    pin_diameter = ${pin_diameter}
    gap = 0.00095 # the half gap between sub-channel assemblies
    heated_length = 1.0
    spacer_z = '0.0'
    spacer_k = '0.0'
  []

  [fuel_pins]
    type = SCMQuadPinMeshGenerator
    input = sub_channel
    nx = 6
    ny = 6
    n_cells = 10
    pitch = 0.0126
    heated_length = 1.0
  []
[]

[FluidProperties]
  [water]
    type = Water97FluidProperties
  []
[]

[SubChannel]
  type = QuadSubChannel1PhaseProblem
  fp = water
  n_blocks = 1
  beta = 0.006
  CT = 2.6
  compute_density = true
  compute_viscosity = true
  compute_power = true
  P_out = ${P_out}
  verbose_subchannel = true
  implicit = true
  segregated = true
[]

[ICs]
  [S_IC]
    type = SCMQuadFlowAreaIC
    variable = S
  []

  [w_perim_IC]
    type = SCMQuadWettedPerimIC
    variable = w_perim
  []

  [q_prime_IC]
    type = SCMQuadPowerIC
    variable = q_prime
    power = 1.0e6 # W
    filename = "power_profile.txt" #type in name of file that describes radial power profile
    block = fuel_pins
  []

  [T_ic]
    type = ConstantIC
    variable = T
    value = ${T_in}
  []

  [Dpin_ic]
    type = ConstantIC
    variable = Dpin
    value = ${pin_diameter}
  []

  [P_ic]
    type = ConstantIC
    variable = P
    value = 0.0
  []

  [DP_ic]
    type = ConstantIC
    variable = DP
    value = 0.0
  []

  [Viscosity_ic]
    type = ViscosityIC
    variable = mu
    p = ${P_out}
    T = T
    fp = water
  []

  [rho_ic]
    type = RhoFromPressureTemperatureIC
    variable = rho
    p = ${P_out}
    T = T
    fp = water
  []

  [h_ic]
    type = SpecificEnthalpyFromPressureTemperatureIC
    variable = h
    p = ${P_out}
    T = T
    fp = water
  []

  [mdot_ic]
    type = ConstantIC
    variable = mdot
    value = 0.0
  []
[]

[AuxKernels]
  [T_in_bc]
    type = ConstantAux
    variable = T
    boundary = inlet
    value = ${T_in}
    execute_on = 'timestep_begin'
    block = sub_channel
  []
  [mdot_in_bc]
    type = SCMMassFlowRateAux
    variable = mdot
    boundary = inlet
    area = S
    mass_flux = report_mass_flux_inlet
    execute_on = 'timestep_begin'
    block = sub_channel
  []
[]

[Postprocessors]
  [report_mass_flux_inlet]
    type = Receiver
    default = ${mass_flux_in}
  []
  [total_pressure_drop]
    type = SubChannelDelta
    variable = P
    execute_on = "timestep_end"
  []
  [T1]
    type = SubChannelPointValue
    variable = T
    index = 0
    execute_on = "timestep_end"
    height = 1
  []
  [T2]
    type = SubChannelPointValue
    variable = T
    index = 7
    execute_on = "timestep_end"
    height = 1
  []
  [T3]
    type = SubChannelPointValue
    variable = T
    index = 14
    execute_on = "timestep_end"
    height = 1
  []
  [T4]
    type = SubChannelPointValue
    variable = T
    index = 21
    execute_on = "timestep_end"
    height = 1
  []
  [T5]
    type = SubChannelPointValue
    variable = T
    index = 28
    execute_on = "timestep_end"
    height = 1
  []
  [T6]
    type = SubChannelPointValue
    variable = T
    index = 35
    execute_on = "timestep_end"
    height = 1
  []
[]

[Outputs]
  csv = true
[]

[Executioner]
  type = Steady
[]

(modules/subchannel/test/tests/problems/psbt/psbt_implicit.i)

T_in = 359.15
# [1e+6 kg/m^2-hour] turns into kg/m^2-sec
mass_flux_in = '${fparse 1e+6 * 17.00 / 3600.}'
P_out = 4.923e6 # Pa
pin_diameter = 0.00950

[QuadSubChannelMesh]
  [sub_channel]
    type = SCMQuadSubChannelMeshGenerator
    nx = 6
    ny = 6
    n_cells = 10
    pitch = 0.0126
    pin_diameter = ${pin_diameter}
    gap = 0.00095 # the half gap between sub-channel assemblies
    heated_length = 1.0
    spacer_z = '0.0'
    spacer_k = '0.0'
  []

  [fuel_pins]
    type = SCMQuadPinMeshGenerator
    input = sub_channel
    nx = 6
    ny = 6
    n_cells = 10
    pitch = 0.0126
    heated_length = 1.0
  []
[]

[FluidProperties]
  [water]
    type = Water97FluidProperties
  []
[]

[SubChannel]
  type = QuadSubChannel1PhaseProblem
  fp = water
  n_blocks = 1
  beta = 0.006
  CT = 2.6
  compute_density = true
  compute_viscosity = true
  compute_power = true
  P_out = ${P_out}
  verbose_subchannel = true
  implicit = true
  segregated = true
[]

[ICs]
  [S_IC]
    type = SCMQuadFlowAreaIC
    variable = S
  []

  [w_perim_IC]
    type = SCMQuadWettedPerimIC
    variable = w_perim
  []

  [q_prime_IC]
    type = SCMQuadPowerIC
    variable = q_prime
    power = 1.0e6 # W
    filename = "power_profile.txt" #type in name of file that describes radial power profile
    block = fuel_pins
  []

  [T_ic]
    type = ConstantIC
    variable = T
    value = ${T_in}
  []

  [Dpin_ic]
    type = ConstantIC
    variable = Dpin
    value = ${pin_diameter}
  []

  [P_ic]
    type = ConstantIC
    variable = P
    value = 0.0
  []

  [DP_ic]
    type = ConstantIC
    variable = DP
    value = 0.0
  []

  [Viscosity_ic]
    type = ViscosityIC
    variable = mu
    p = ${P_out}
    T = T
    fp = water
  []

  [rho_ic]
    type = RhoFromPressureTemperatureIC
    variable = rho
    p = ${P_out}
    T = T
    fp = water
  []

  [h_ic]
    type = SpecificEnthalpyFromPressureTemperatureIC
    variable = h
    p = ${P_out}
    T = T
    fp = water
  []

  [mdot_ic]
    type = ConstantIC
    variable = mdot
    value = 0.0
  []
[]

[AuxKernels]
  [T_in_bc]
    type = ConstantAux
    variable = T
    boundary = inlet
    value = ${T_in}
    execute_on = 'timestep_begin'
    block = sub_channel
  []
  [mdot_in_bc]
    type = SCMMassFlowRateAux
    variable = mdot
    boundary = inlet
    area = S
    mass_flux = report_mass_flux_inlet
    execute_on = 'timestep_begin'
    block = sub_channel
  []
[]

[Postprocessors]
  [report_mass_flux_inlet]
    type = Receiver
    default = ${mass_flux_in}
  []
  [total_pressure_drop]
    type = SubChannelDelta
    variable = P
    execute_on = "timestep_end"
  []
  [T1]
    type = SubChannelPointValue
    variable = T
    index = 0
    execute_on = "timestep_end"
    height = 1
  []
  [T2]
    type = SubChannelPointValue
    variable = T
    index = 7
    execute_on = "timestep_end"
    height = 1
  []
  [T3]
    type = SubChannelPointValue
    variable = T
    index = 14
    execute_on = "timestep_end"
    height = 1
  []
  [T4]
    type = SubChannelPointValue
    variable = T
    index = 21
    execute_on = "timestep_end"
    height = 1
  []
  [T5]
    type = SubChannelPointValue
    variable = T
    index = 28
    execute_on = "timestep_end"
    height = 1
  []
  [T6]
    type = SubChannelPointValue
    variable = T
    index = 35
    execute_on = "timestep_end"
    height = 1
  []
[]

[Outputs]
  csv = true
[]

[Executioner]
  type = Steady
[]

(modules/subchannel/validation/psbt/psbt_null_transient/psbt_ss.i)

# This is an input file based on M. Avramova et. all 2012,
# OECD/NRC Benchmark Based on NUPEC PWR
# Sub-channel and Bundle Tests (PSBT). Volume III: Departure from Nucleate Boiling
T_in = 359.15
# [1e+6 kg/m^2-hour] turns into kg/m^2-sec
mass_flux_in = '${fparse 1e+6 * 17.00 / 3600.}'
P_out = 4.923e6 # Pa

[QuadSubChannelMesh]
  [sub_channel]
    type = SCMQuadSubChannelMeshGenerator
    nx = 6
    ny = 6
    n_cells = 50
    pitch = 0.0126
    pin_diameter = 0.00950
    gap = 0.00095
    heated_length = 3.658
    spacer_z = '0.0 0.229 0.457 0.686 0.914 1.143 1.372 1.600 1.829 2.057 2.286 2.515 2.743 2.972 3.200 3.429'
    spacer_k = '0.7 0.4 1.0 0.4 1.0 0.4 1.0 0.4 1.0 0.4 1.0 0.4 1.0 0.4 1.0 0.4'
  []
[]

[FluidProperties]
  [water]
    type = Water97FluidProperties
  []
[]

[SubChannel]
  type = QuadSubChannel1PhaseProblem
  fp = water
  n_blocks = 1
  beta = 0.006
  CT = 2.0
  P_tol = 1e-6
  T_tol = 1e-6
  compute_density = true
  compute_viscosity = true
  compute_power = true
  P_out = ${P_out}
[]

[ICs]
  [S_IC]
    type = SCMQuadFlowAreaIC
    variable = S
  []

  [w_perim_IC]
    type = SCMQuadWettedPerimIC
    variable = w_perim
  []

  [q_prime_IC]
    type = SCMQuadPowerIC
    variable = q_prime
    power = 3.44e6 # W
    filename = "power_profile.txt"
  []

  [T_ic]
    type = ConstantIC
    variable = T
    value = ${T_in}
  []

  [P_ic]
    type = ConstantIC
    variable = P
    value = 0.0
  []

  [DP_ic]
    type = ConstantIC
    variable = DP
    value = 0.0
  []

  [Viscosity_ic]
    type = ViscosityIC
    variable = mu
    p = ${P_out}
    T = T
    fp = water
  []

  [rho_ic]
    type = RhoFromPressureTemperatureIC
    variable = rho
    p = ${P_out}
    T = T
    fp = water
  []

  [h_ic]
    type = SpecificEnthalpyFromPressureTemperatureIC
    variable = h
    p = ${P_out}
    T = T
    fp = water
  []

  [mdot_ic]
    type = ConstantIC
    variable = mdot
    value = 0.0
  []
[]

[AuxKernels]
  [T_in_bc]
    type = ConstantAux
    variable = T
    boundary = inlet
    value = ${T_in}
    execute_on = 'timestep_begin'
  []
  [mdot_in_bc]
    type = SCMMassFlowRateAux
    variable = mdot
    boundary = inlet
    area = S
    mass_flux = ${mass_flux_in}
    execute_on = 'timestep_begin'
  []
[]

[Outputs]
  exodus = true
  checkpoint = true
  [Temp_Out_MATRIX]
    type = QuadSubChannelNormalSliceValues
    variable = T
    execute_on = final
    file_base = "Temp_Out.txt"
    height = 3.658
  []
  [mdot_Out_MATRIX]
    type = QuadSubChannelNormalSliceValues
    variable = mdot
    execute_on = final
    file_base = "mdot_Out.txt"
    height = 3.658
  []
  [mdot_In_MATRIX]
    type = QuadSubChannelNormalSliceValues
    variable = mdot
    execute_on = final
    file_base = "mdot_In.txt"
    height = 0.0
  []
[]

[Executioner]
  type = Steady
[]

################################################################################
# A multiapp that projects data to a detailed mesh
################################################################################

[MultiApps]
  [viz]
    type = FullSolveMultiApp
    input_files = "3d.i"
    execute_on = "timestep_end"
  []
[]

[Transfers]
  [xfer]
    type = SCMSolutionTransfer
    to_multi_app = viz
    variable = 'mdot SumWij P DP h T rho mu q_prime'
  []
[]

(modules/subchannel/verification/friction_model_verification/two_channel2.i)

T_in = 473.15 # K
mass_flux_in = 3500 # kg /sec m2
P_out = 155e+5 # Pa

[QuadSubChannelMesh]
  [sub_channel]
    type = SCMQuadSubChannelMeshGenerator
    nx = 2
    ny = 1
    n_cells = 100
    pitch = 0.0126
    pin_diameter = 0.00950
    gap = 0.00095 # the half gap between sub-channel assemblies
    heated_length = 10.0
    spacer_z = '0.0'
    spacer_k = '0.0'
  []
[]

[Functions]
  [S_fn]
    type = ParsedFunction
    value = if(x>0.0,0.002,0.001)
  []
[]

[FluidProperties]
  [water]
    type = Water97FluidProperties
  []
[]

[SubChannel]
  type = QuadSubChannel1PhaseProblem
  fp = water
  n_blocks = 1
  beta = 0.006
  CT = 0.0
  compute_density = true
  compute_viscosity = true
  compute_power = true
  P_out = ${P_out}
  default_friction_model = false
[]

[ICs]
  [S_ic]
    type = FunctionIC
    variable = S
    function = S_fn
  []

  [w_perim_IC]
    type = ConstantIC
    variable = w_perim
    value = 0.34188034
  []

  [q_prime_IC]
    type = ConstantIC
    variable = q_prime
    value = 0.0
  []

  [T_ic]
    type = ConstantIC
    variable = T
    value = ${T_in}
  []

  [P_ic]
    type = ConstantIC
    variable = P
    value = 0.0
  []

  [DP_ic]
    type = ConstantIC
    variable = DP
    value = 0.0
  []

  [Viscosity_ic]
    type = ViscosityIC
    variable = mu
    p = ${P_out}
    T = T
    fp = water
  []

  [rho_ic]
    type = RhoFromPressureTemperatureIC
    variable = rho
    p = ${P_out}
    T = T
    fp = water
  []

  [h_ic]
    type = SpecificEnthalpyFromPressureTemperatureIC
    variable = h
    p = ${P_out}
    T = T
    fp = water
  []

  [mdot_ic]
    type = ConstantIC
    variable = mdot
    value = 0.0
  []
[]

[AuxKernels]
  [T_in_bc]
    type = ConstantAux
    variable = T
    boundary = inlet
    value = ${T_in}
    execute_on = 'timestep_begin'
  []
  [mdot_in_bc]
    type = SCMMassFlowRateAux
    variable = mdot
    boundary = inlet
    area = S
    mass_flux = ${mass_flux_in}
    execute_on = 'timestep_begin'
  []
[]

[Postprocessors]
  [mdot_1]
    type = SubChannelPointValue
    variable = mdot
    index = 0
    execute_on = 'initial timestep_end'
    height = 10.0
  []
  [mdot_2]
    type = SubChannelPointValue
    variable = mdot
    index = 1
    execute_on = 'initial timestep_end'
    height = 10.0
  []
[]

[Outputs]
  csv = true
[]

[Executioner]
  type = Steady
[]

(modules/subchannel/examples/heating_test/3X3_channel.i)

mass_flux_in = 3500 # kg /sec m2
T_in = 297.039 # K
P_out = 101325 # Pa
pitch = 0.0126
unheated_length_entry = 2.5
heated_length = 5.0
unheated_length_exit = 2.5
n_cells = 20

[QuadSubChannelMesh]
  [sub_channel]
    type = SCMQuadSubChannelMeshGenerator
    nx = 3
    ny = 3
    n_cells = '${n_cells}'
    pitch = '${pitch}'
    pin_diameter = 0.00950
    gap = 0.00095
    unheated_length_entry = '${unheated_length_entry}'
    heated_length = '${heated_length}'
    unheated_length_exit = '${unheated_length_exit}'
    spacer_z ='0.0'
    spacer_k ='0.0'
  []
[]

[FluidProperties]
  [water]
    type = Water97FluidProperties
  []
[]

[SubChannel]
  type = QuadSubChannel1PhaseProblem
  fp = water
  n_blocks = 1
  beta = 0.006
  CT = 2.0
  P_tol = 1e-6
  T_tol = 1e-6
  compute_density = true
  compute_viscosity = true
  compute_power = true
  P_out = ${P_out}
[]

[ICs]
  [S_IC]
    type = SCMQuadFlowAreaIC
    variable = S
  []

  [T_ic]
    type = ConstantIC
    variable = T
    value = ${T_in}
  []

  [w_perim_IC]
    type = SCMQuadWettedPerimIC
    variable = w_perim
  []

  [q_prime_IC]
    type = SCMQuadPowerIC
    variable = q_prime
    power = 10000.0 # W
    filename = "power_profile.txt"
  []

  [P_ic]
    type = ConstantIC
    variable = P
    value = 0.0
  []

  [DP_ic]
    type = ConstantIC
    variable = DP
    value = 0.0
  []

  [Viscosity_ic]
    type = ViscosityIC
    variable = mu
    p = ${P_out}
    T = T
    fp = water
  []

  [rho_ic]
    type = RhoFromPressureTemperatureIC
    variable = rho
    p = ${P_out}
    T = T
    fp = water
  []

  [h_ic]
    type = SpecificEnthalpyFromPressureTemperatureIC
    variable = h
    p = ${P_out}
    T = T
    fp = water
  []

  [mdot_ic]
    type = ConstantIC
    variable = mdot
    value = 0.0
  []
[]

[AuxKernels]
  [T_in_bc]
    type = ConstantAux
    variable = T
    boundary = inlet
    value = ${T_in}
    execute_on = 'timestep_begin'
  []
  [mdot_in_bc]
    type = SCMMassFlowRateAux
    variable = mdot
    boundary = inlet
    area = S
    mass_flux = ${mass_flux_in}
    execute_on = 'timestep_begin'
  []
[]

[Outputs]
  exodus = true
  [h_3]
    type = QuadSubChannelNormalSliceValues
    variable = h
    execute_on = final
    file_base = "h_3.txt"
    height = 10.0
  []
  [h_2]
    type = QuadSubChannelNormalSliceValues
    variable = h
    execute_on = final
    file_base = "h_2.txt"
    height = 7.5
  []
  [h_1]
    type = QuadSubChannelNormalSliceValues
    variable = h
    execute_on = final
    file_base = "h_1.txt"
    height = 2.5
  []
  [h_0]
    type = QuadSubChannelNormalSliceValues
    variable = h
    execute_on = final
    file_base = "h_0.txt"
    height = 0.0
  []
  [mdot_3]
    type = QuadSubChannelNormalSliceValues
    variable = mdot
    execute_on = final
    file_base = "mdot_3.txt"
    height = 10.0
  []
  [mdot_2]
    type = QuadSubChannelNormalSliceValues
    variable = mdot
    execute_on = final
    file_base = "mdot_2.txt"
    height = 7.5
  []
  [mdot_1]
    type = QuadSubChannelNormalSliceValues
    variable = mdot
    execute_on = final
    file_base = "mdot_1.txt"
    height = 2.5
  []
  [mdot_0]
    type = QuadSubChannelNormalSliceValues
    variable = mdot
    execute_on = final
    file_base = "mdot_0.txt"
    height = 0.0
  []
[]

[Executioner]
  type = Steady
[]

################################################################################
# A multiapp that projects data to a detailed mesh
################################################################################

[MultiApps]
  [viz]
    type = FullSolveMultiApp
    input_files = "3d.i"
    execute_on = "timestep_end"
  []
[]

[Transfers]
  [xfer]
    type = SCMSolutionTransfer
    to_multi_app = viz
    variable = 'mdot SumWij P DP h T rho mu q_prime S w_perim'
  []
[]

(modules/subchannel/examples/mesh_generator/psbt_mesh_generator_test.i)

T_in = 359.15
# [1e+6 kg/m^2-hour] turns into kg/m^2-sec
mass_flux_in = '${fparse 1e+6 * 17.0 / 3600.}'
P_out = 4.923e6 # Pa

[QuadSubChannelMesh]
  [sub_channel]
    type = SCMQuadSubChannelMeshGenerator
    nx = 6
    ny = 6
    n_cells = 20
    pitch = 0.0126
    pin_diameter = 0.00950
    gap = 0.00095
    heated_length = 1.00
    spacer_z = '0.5'
    spacer_k = '0.5'
  []

  [fuel_pins]
    type = SCMQuadPinMeshGenerator
    input = sub_channel
    nx = 6
    ny = 6
    n_cells = 20
    pitch = 0.0126
    heated_length = 1.00
  []
[]

[AuxVariables]
  [mdot]
    block = sub_channel
  []
  [SumWij]
    block = sub_channel
  []
  [P]
    block = sub_channel
  []
  [DP]
    block = sub_channel
  []
  [h]
    block = sub_channel
  []
  [T]
    block = sub_channel
  []
  [Tpin]
    block = fuel_pins
  []
  [Dpin]
    block = fuel_pins
  []
  [rho]
    block = sub_channel
  []
  [mu]
    block = sub_channel
  []
  [S]
    block = sub_channel
  []
  [w_perim]
    block = sub_channel
  []
  [q_prime]
    block = sub_channel
  []
[]

[FluidProperties]
  [water]
    type = Water97FluidProperties
  []
[]

[SubChannel]
  type = QuadSubChannel1PhaseProblem
  fp = water
  n_blocks = 1
  beta = 0.08
  CT = 2.6
  P_tol = 1e-6
  T_tol = 1e-6
  compute_density = true
  compute_viscosity = true
  compute_power = true
  P_out = ${P_out}
[]

[ICs]
  [S_IC]
    type = SCMQuadFlowAreaIC
    variable = S
  []

  [w_perim_IC]
    type = SCMQuadWettedPerimIC
    variable = w_perim
  []

  [q_prime_IC]
    type = SCMQuadPowerIC
    variable = q_prime
    power = 1.00e6 # W
    filename = "power_profile.txt" #
  []

  [T_ic]
    type = ConstantIC
    variable = T
    value = ${T_in}
  []

  [Tpin_ic]
    type = ConstantIC
    variable = Tpin
    value = 0.0
  []

  [Dpin_ic]
    type = ConstantIC
    variable = Dpin
    value = 0.00950
  []

  [P_ic]
    type = ConstantIC
    variable = P
    value = 0.0
  []

  [DP_ic]
    type = ConstantIC
    variable = DP
    value = 0.0
  []

  [Viscosity_ic]
    type = ViscosityIC
    variable = mu
    p = ${P_out}
    T = T
    fp = water
  []

  [rho_ic]
    type = RhoFromPressureTemperatureIC
    variable = rho
    p = ${P_out}
    T = T
    fp = water
  []

  [h_ic]
    type = SpecificEnthalpyFromPressureTemperatureIC
    variable = h
    p = ${P_out}
    T = T
    fp = water
  []

  [mdot_ic]
    type = ConstantIC
    variable = mdot
    value = 0.0
  []
[]

[AuxKernels]
  [T_in_bc]
    type = ConstantAux
    variable = T
    boundary = inlet
    value = ${T_in}
    execute_on = 'timestep_begin'
  []
  [mdot_in_bc]
    type = SCMMassFlowRateAux
    variable = mdot
    boundary = inlet
    area = S
    mass_flux = ${mass_flux_in}
    execute_on = 'timestep_begin'
  []
[]

[Outputs]
  exodus = true
  checkpoint = false
  [Temp_Out_MATRIX]
    type = QuadSubChannelNormalSliceValues
    variable = T
    execute_on = final
    file_base = "Temp_Out.txt"
    height = 3.658
  []
  [mdot_Out_MATRIX]
    type = QuadSubChannelNormalSliceValues
    variable = mdot
    execute_on = final
    file_base = "mdot_Out.txt"
    height = 3.658
  []
  [mdot_In_MATRIX]
    type = QuadSubChannelNormalSliceValues
    variable = mdot
    execute_on = final
    file_base = "mdot_In.txt"
    height = 0.0
  []
[]

[Executioner]
  type = Steady
[]

################################################################################
# A multiapp that projects data to a detailed mesh
################################################################################

[MultiApps]
  [viz]
    type = FullSolveMultiApp
    input_files = "3d.i"
    execute_on = "timestep_end"
  []
[]

[Transfers]
  [xfer]
    type = SCMSolutionTransfer
    to_multi_app = viz
    variable = 'mdot SumWij P DP h T rho mu q_prime S'
  []
[]

(modules/subchannel/validation/psbt/psbt_null_transient/psbt_transient.i)

# This is an input file based on M. Avramova et al. 2012,
# OECD/NRC Benchmark Based on NUPEC PWR
# Sub-channel and Bundle Tests (PSBT). Volume III: Departure from Nucleate Boiling
T_in = 359.15
# [1e+6 kg/m^2-hour] turns into kg/m^2-sec
mass_flux_in = '${fparse 1e+6 * 17.00 / 3600.}'
P_out = 4.923e6 # Pa

[QuadSubChannelMesh]
  [sub_channel]
    type = SCMQuadSubChannelMeshGenerator
    nx = 6
    ny = 6
    n_cells = 50
    pitch = 0.0126
    pin_diameter = 0.00950
    gap = 0.00095
    heated_length = 3.658
    spacer_z = '0.0 0.229 0.457 0.686 0.914 1.143 1.372 1.600 1.829 2.057 2.286 2.515 2.743 2.972 3.200 3.429'
    spacer_k = '0.7 0.4 1.0 0.4 1.0 0.4 1.0 0.4 1.0 0.4 1.0 0.4 1.0 0.4 1.0 0.4'
  []
[]

[UserObjects]
  [steady_sln]
    type = SolutionUserObject
    mesh = psbt_ss_out.e
    timestep = LATEST
    system_variables = 'mdot SumWij P DP h T rho mu S w_perim q_prime'
  []
[]

[FluidProperties]
  [water]
    type = Water97FluidProperties
  []
[]

[SubChannel]
  type = QuadSubChannel1PhaseProblem
  fp = water
  n_blocks = 1
  beta = 0.006
  CT = 2.0
  P_tol = 1e-6
  T_tol = 1e-6
  compute_density = true
  compute_viscosity = true
  compute_power = true
  P_out = ${P_out}
  restart_file_base = psbt_SS_out_cp/LATEST
  skip_additional_restart_data = true
[]

[Functions]
  [mdot_ic_fn]
    type = SolutionFunction
    solution = steady_sln
    from_variable = mdot
  []

  [P_ic_fn]
    type = SolutionFunction
    solution = steady_sln
    from_variable = P
  []

  [DP_ic_fn]
    type = SolutionFunction
    solution = steady_sln
    from_variable = DP
  []

  [h_ic_fn]
    type = SolutionFunction
    solution = steady_sln
    from_variable = h
  []

  [T_ic_fn]
    type = SolutionFunction
    solution = steady_sln
    from_variable = T
  []

  [rho_ic_fn]
    type = SolutionFunction
    solution = steady_sln
    from_variable = rho
  []

  [Mu_ic_fn]
    type = SolutionFunction
    solution = steady_sln
    from_variable = mu
  []
[]

[ICs]
  [S_IC]
    type = SCMQuadFlowAreaIC
    variable = S
  []

  [w_perim_IC]
    type = SCMQuadWettedPerimIC
    variable = w_perim
  []

  [q_prime_IC]
    type = SCMQuadPowerIC
    variable = q_prime
    power = 3.44e6 # W
    filename = "power_profile.txt"
  []

  [T_ic]
    type = FunctionIC
    variable = T
    function = T_ic_fn
  []

  [P_ic]
    type = FunctionIC
    variable = P
    function = P_ic_fn
  []

  [DP_ic]
    type = FunctionIC
    variable = DP
    function = DP_ic_fn
  []

  [Viscosity_ic]
    type = FunctionIC
    variable = mu
    function = Mu_ic_fn
  []

  [rho_ic]
    type = FunctionIC
    variable = rho
    function = rho_ic_fn
  []

  [h_ic]
    type = FunctionIC
    variable = h
    function = h_ic_fn
  []

  [mdot_ic]
    type = FunctionIC
    variable = mdot
    function = mdot_ic_fn
  []
[]

[AuxKernels]
  [T_in_bc]
    type = ConstantAux
    variable = T
    boundary = inlet
    value = ${T_in}
    execute_on = 'timestep_begin'
  []
  [mdot_in_bc]
    type = SCMMassFlowRateAux
    variable = mdot
    boundary = inlet
    area = S
    mass_flux = ${mass_flux_in}
    execute_on = 'timestep_begin'
  []
[]

[Outputs]
  exodus = true
  [Temp_Out_MATRIX]
    type = QuadSubChannelNormalSliceValues
    variable = T
    execute_on = TIMESTEP_END
    file_base = "Temp_Out.txt"
    height = 3.658
  []
  [mdot_Out_MATRIX]
    type = QuadSubChannelNormalSliceValues
    variable = mdot
    execute_on = TIMESTEP_END
    file_base = "mdot_Out.txt"
    height = 3.658
  []
  [mdot_In_MATRIX]
    type = QuadSubChannelNormalSliceValues
    variable = mdot
    execute_on = TIMESTEP_END
    file_base = "mdot_In.txt"
    height = 0.0
  []
[]

[Executioner]
  type = Transient
  start_time = 0.0
  end_time = 0.2
  dt = 0.1
[]

################################################################################
# A multiapp that projects data to a detailed mesh
################################################################################

[MultiApps]
  [viz]
    type = FullSolveMultiApp
    input_files = "3d.i"
    execute_on = "timestep_end"
  []
[]

[Transfers]
  [xfer]
    type = SCMSolutionTransfer
    to_multi_app = viz
    variable = 'mdot SumWij P DP h T rho mu q_prime S'
  []
[]

(modules/subchannel/test/tests/problems/psbt/psbt_explicit_staggered.i)

T_in = 359.15
# [1e+6 kg/m^2-hour] turns into kg/m^2-sec
mass_flux_in = '${fparse 1e+6 * 17.00 / 3600.}'
P_out = 4.923e6 # Pa
pin_diameter = 0.00950

[QuadSubChannelMesh]
  [sub_channel]
    type = SCMQuadSubChannelMeshGenerator
    nx = 6
    ny = 6
    n_cells = 10
    pitch = 0.0126
    pin_diameter = ${pin_diameter}
    gap = 0.00095 # the half gap between sub-channel assemblies
    heated_length = 1.0
    spacer_z = '0.0'
    spacer_k = '0.0'
  []

  [fuel_pins]
    type = SCMQuadPinMeshGenerator
    input = sub_channel
    nx = 6
    ny = 6
    n_cells = 10
    pitch = 0.0126
    heated_length = 1.0
  []
[]

[FluidProperties]
  [water]
    type = Water97FluidProperties
  []
[]

[SubChannel]
  type = QuadSubChannel1PhaseProblem
  fp = water
  n_blocks = 1
  beta = 0.006
  CT = 2.6
  compute_density = true
  compute_viscosity = true
  compute_power = true
  P_out = ${P_out}
  verbose_subchannel = true
  staggered_pressure = true
[]

[ICs]
  [S_IC]
    type = SCMQuadFlowAreaIC
    variable = S
  []

  [w_perim_IC]
    type = SCMQuadWettedPerimIC
    variable = w_perim
  []

  [q_prime_IC]
    type = SCMQuadPowerIC
    variable = q_prime
    power = 1.0e6 # W
    filename = "power_profile.txt" #type in name of file that describes radial power profile
    block = fuel_pins
  []

  [T_ic]
    type = ConstantIC
    variable = T
    value = ${T_in}
  []

  [Dpin_ic]
    type = ConstantIC
    variable = Dpin
    value = ${pin_diameter}
  []

  [P_ic]
    type = ConstantIC
    variable = P
    value = 0.0
  []

  [DP_ic]
    type = ConstantIC
    variable = DP
    value = 0.0
  []

  [Viscosity_ic]
    type = ViscosityIC
    variable = mu
    p = ${P_out}
    T = T
    fp = water
  []

  [rho_ic]
    type = RhoFromPressureTemperatureIC
    variable = rho
    p = ${P_out}
    T = T
    fp = water
  []

  [h_ic]
    type = SpecificEnthalpyFromPressureTemperatureIC
    variable = h
    p = ${P_out}
    T = T
    fp = water
  []

  [mdot_ic]
    type = ConstantIC
    variable = mdot
    value = 0.0
  []
[]

[AuxKernels]
  [T_in_bc]
    type = ConstantAux
    variable = T
    boundary = inlet
    value = ${T_in}
    execute_on = 'timestep_begin'
    block = sub_channel
  []
  [mdot_in_bc]
    type = SCMMassFlowRateAux
    variable = mdot
    boundary = inlet
    area = S
    mass_flux = report_mass_flux_inlet
    execute_on = 'timestep_begin'
    block = sub_channel
  []
[]

[Postprocessors]
  [report_mass_flux_inlet]
    type = Receiver
    default = ${mass_flux_in}
  []
  [total_pressure_drop]
    type = SubChannelDelta
    variable = P
    execute_on = "timestep_end"
  []
  [T1]
    type = SubChannelPointValue
    variable = T
    index = 0
    execute_on = "timestep_end"
    height = 1
  []
  [T2]
    type = SubChannelPointValue
    variable = T
    index = 7
    execute_on = "timestep_end"
    height = 1
  []
  [T3]
    type = SubChannelPointValue
    variable = T
    index = 14
    execute_on = "timestep_end"
    height = 1
  []
  [T4]
    type = SubChannelPointValue
    variable = T
    index = 21
    execute_on = "timestep_end"
    height = 1
  []
  [T5]
    type = SubChannelPointValue
    variable = T
    index = 28
    execute_on = "timestep_end"
    height = 1
  []
  [T6]
    type = SubChannelPointValue
    variable = T
    index = 35
    execute_on = "timestep_end"
    height = 1
  []
[]

[Outputs]
  csv = true
[]

[Executioner]
  type = Steady
[]

(modules/subchannel/verification/enthalpy_mixing_verification/two_channel.i)

mass_flux_in = 3500 # kg /sec m2
P_out = 155e+5 # Pa

[QuadSubChannelMesh]
  [sub_channel]
    type = SCMQuadSubChannelMeshGenerator
    nx = 2
    ny = 1
    n_cells = 100
    pitch = 0.0126
    pin_diameter = 0.00950
    gap = 0.00095
    heated_length = 10.0
    spacer_z = '0.0'
    spacer_k = '0.0'
  []
[]

[Functions]
  [T_fn]
    type = ParsedFunction
    value = if(x>0.0,483.10,473.10)
  []
[]

[FluidProperties]
  [water]
    type = Water97FluidProperties
  []
[]

[SubChannel]
  type = QuadSubChannel1PhaseProblem
  fp = water
  n_blocks = 1
  beta = 0.006
  CT = 2.0
  P_tol = 1e-6
  T_tol = 1e-6
  compute_density = true
  compute_viscosity = true
  compute_power = true
  P_out = ${P_out}
[]

[ICs]
  [S_ic]
    type = ConstantIC
    variable = S
    value = 8.78778158e-05
  []

  [T_ic]
    type = FunctionIC
    variable = T
    function = T_fn
  []

  [w_perim_IC]
    type = ConstantIC
    variable = w_perim
    value = 0.34188034
  []

  [q_prime_IC]
    type = ConstantIC
    variable = q_prime
    value = 0.0
  []

  [P_ic]
    type = ConstantIC
    variable = P
    value = 0.0
  []

  [DP_ic]
    type = ConstantIC
    variable = DP
    value = 0.0
  []

  [Viscosity_ic]
    type = ViscosityIC
    variable = mu
    p = ${P_out}
    T = T
    fp = water
  []

  [rho_ic]
    type = RhoFromPressureTemperatureIC
    variable = rho
    p = ${P_out}
    T = T
    fp = water
  []

  [h_ic]
    type = SpecificEnthalpyFromPressureTemperatureIC
    variable = h
    p = ${P_out}
    T = T
    fp = water
  []

  [mdot_ic]
    type = ConstantIC
    variable = mdot
    value = 0.0
  []
[]

[AuxKernels]
  [mdot_in_bc]
    type = SCMMassFlowRateAux
    variable = mdot
    boundary = inlet
    area = S
    mass_flux = ${mass_flux_in}
    execute_on = 'timestep_begin'
  []
[]

[Outputs]
  exodus = true
  csv = true
[]

[Postprocessors]
  [Temp_1]
    type = SubChannelPointValue
    variable = T
    index = 0
    execute_on = 'initial timestep_end'
    height = 10.0
  []
  [Temp_2]
    type = SubChannelPointValue
    variable = T
    index = 1
    execute_on = 'initial timestep_end'
    height = 10.0
  []
[]

[Executioner]
  type = Steady
[]

################################################################################
# A multiapp that projects data to a detailed mesh
################################################################################

[MultiApps]
  [viz]
    type = FullSolveMultiApp
    input_files = "3d.i"
    execute_on = "timestep_end"
  []
[]

[Transfers]
  [xfer]
    type = SCMSolutionTransfer
    to_multi_app = viz
    variable = 'mdot SumWij P DP h T rho mu q_prime S'
  []
[]

(modules/subchannel/test/tests/restart/transient.i)

T_in = 359.15
# [1e+6 kg/m^2-hour] turns into kg/m^2-sec
mass_flux_in = '${fparse 1e+6 * 17.00 / 3600.}'
P_out = 4.923e6 # Pa

[QuadSubChannelMesh]
  [sub_channel]
    type = SCMQuadSubChannelMeshGenerator
    nx = 3
    ny = 3
    n_cells = 10
    pitch = 0.0126
    pin_diameter = 0.00950
    gap = 0.00095 # the half gap between sub-channel assemblies
    heated_length = 1
    spacer_z = '0.0'
    spacer_k = '0.0'
  []
[]

[UserObjects]
  [steady_sln]
    type = SolutionUserObject
    mesh = steady_out.e
    timestep = LATEST
    system_variables = 'mdot SumWij P DP h T Tpin rho mu S w_perim q_prime'
  []
[]

[FluidProperties]
  [water]
    type = Water97FluidProperties
  []
[]

[SubChannel]
  type = QuadSubChannel1PhaseProblem
  fp = water
  n_blocks = 1
  beta = 0.006
  CT = 1.8
  compute_density = true
  compute_viscosity = true
  compute_power = true
  P_out = ${P_out}
  restart_file_base = steady_out_cp/LATEST
  skip_additional_restart_data = true
  allow_initial_conditions_with_restart = true
[]

[Functions]
  [mdot_ic_fn]
    type = SolutionFunction
    solution = steady_sln
    from_variable = mdot
  []

  [P_ic_fn]
    type = SolutionFunction
    solution = steady_sln
    from_variable = P
  []

  [DP_ic_fn]
    type = SolutionFunction
    solution = steady_sln
    from_variable = DP
  []

  [h_ic_fn]
    type = SolutionFunction
    solution = steady_sln
    from_variable = h
  []

  [T_ic_fn]
    type = SolutionFunction
    solution = steady_sln
    from_variable = T
  []

  [rho_ic_fn]
    type = SolutionFunction
    solution = steady_sln
    from_variable = rho
  []

  [mu_ic_fn]
    type = SolutionFunction
    solution = steady_sln
    from_variable = mu
  []
[]

[ICs]
  [S_ic]
    type = SCMQuadFlowAreaIC
    variable = S
  []

  [w_perim_ic]
    type = SCMQuadWettedPerimIC
    variable = w_perim
  []

  [q_prime_ic]
    type = SCMQuadPowerIC
    variable = q_prime
    power = 1e6
    filename = "power_profile.txt"
  []

  [T_ic]
    type = FunctionIC
    variable = T
    function = T_ic_fn
  []

  [P_ic]
    type = FunctionIC
    variable = P
    function = P_ic_fn
  []

  [DP_ic]
    type = FunctionIC
    variable = DP
    function = DP_ic_fn
  []

  [viscosity_ic]
    type = FunctionIC
    variable = mu
    function = mu_ic_fn
  []

  [rho_ic]
    type = FunctionIC
    variable = rho
    function = rho_ic_fn
  []

  [h_ic]
    type = FunctionIC
    variable = h
    function = h_ic_fn
  []

  [mdot_ic]
    type = FunctionIC
    variable = mdot
    function = mdot_ic_fn
  []
[]

[AuxKernels]
  [T_in_bc]
    type = ConstantAux
    variable = T
    boundary = inlet
    value = ${T_in}
    execute_on = 'timestep_begin'
  []
  [mdot_in_bc]
    type = SCMMassFlowRateAux
    variable = mdot
    boundary = inlet
    area = S
    mass_flux = ${mass_flux_in}
    execute_on = 'timestep_begin'
  []
[]

[Outputs]
  exodus = true
[]

[Executioner]
  type = Transient
  start_time = 0.0
  end_time = 0.2
  dt = 0.1
[]

(modules/subchannel/verification/friction_model_verification/two_channel.i)

T_in = 473.15 # K
mass_flux_in = 3500 # kg /sec m2
P_out = 155e+5 # Pa

[QuadSubChannelMesh]
  [sub_channel]
    type = SCMQuadSubChannelMeshGenerator
    nx = 1
    ny = 2
    n_cells = 100
    pitch = 0.0126
    pin_diameter = 0.00950
    gap = 0.00095
    heated_length = 10.0
    spacer_z = '0.0'
    spacer_k = '0.0'
  []
[]

[Functions]
  [S_fn]
    type = ParsedFunction
    expression = if(y>0.0,0.002,0.001)
  []
[]

[FluidProperties]
  [water]
    type = Water97FluidProperties
  []
[]

[SubChannel]
  type = QuadSubChannel1PhaseProblem
  fp = water
  n_blocks = 1
  beta = 0.006
  CT = 0.0
  P_tol = 1e-6
  T_tol = 1e-6
  implicit = false
  compute_density = true
  compute_viscosity = true
  compute_power = true
  P_out = ${P_out}
[]

[ICs]
  [S_ic]
    type = FunctionIC
    variable = S
    function = S_fn
  []

  [w_perim_IC]
    type = ConstantIC
    variable = w_perim
    value = 0.34188034
  []

  [q_prime_IC]
    type = ConstantIC
    variable = q_prime
    value = 0.0
  []

  [T_ic]
    type = ConstantIC
    variable = T
    value = ${T_in}
  []

  [P_ic]
    type = ConstantIC
    variable = P
    value = 0.0
  []

  [DP_ic]
    type = ConstantIC
    variable = DP
    value = 0.0
  []

  [Viscosity_ic]
    type = ViscosityIC
    variable = mu
    p = ${P_out}
    T = T
    fp = water
  []

  [rho_ic]
    type = RhoFromPressureTemperatureIC
    variable = rho
    p = ${P_out}
    T = T
    fp = water
  []

  [h_ic]
    type = SpecificEnthalpyFromPressureTemperatureIC
    variable = h
    p = ${P_out}
    T = T
    fp = water
  []

  [mdot_ic]
    type = ConstantIC
    variable = mdot
    value = 0.0
  []
[]

[AuxKernels]
  [T_in_bc]
    type = ConstantAux
    variable = T
    boundary = inlet
    value = ${T_in}
    execute_on = 'timestep_begin'
  []
  [mdot_in_bc]
    type = SCMMassFlowRateAux
    variable = mdot
    boundary = inlet
    area = S
    mass_flux = ${mass_flux_in}
    execute_on = 'timestep_begin'
  []
[]

[Outputs]
  csv = true
[]

[Postprocessors]
  [mdot_1]
    type = SubChannelPointValue
    variable = mdot
    index = 0
    execute_on = 'initial timestep_end'
    height = 10.0
  []
  [mdot_2]
    type = SubChannelPointValue
    variable = mdot
    index = 1
    execute_on = 'initial timestep_end'
    height = 10.0
  []
[]

[Executioner]
  type = Steady
[]

################################################################################
# A multiapp that projects data to a detailed mesh
################################################################################

[MultiApps]
  [viz]
    type = FullSolveMultiApp
    input_files = "3d.i"
    execute_on = "timestep_end"
  []
[]

[Transfers]
  [xfer]
    type = SCMSolutionTransfer
    to_multi_app = viz
    variable = 'mdot SumWij P DP h T rho mu q_prime S'
  []
[]

(modules/subchannel/test/tests/problems/psbt/psbt_full_monolithic_staggered.i)

T_in = 359.15
# [1e+6 kg/m^2-hour] turns into kg/m^2-sec
mass_flux_in = '${fparse 1e+6 * 17.00 / 3600.}'
P_out = 4.923e6 # Pa
pin_diameter = 0.00950

[QuadSubChannelMesh]
  [sub_channel]
    type = SCMQuadSubChannelMeshGenerator
    nx = 6
    ny = 6
    n_cells = 10
    pitch = 0.0126
    pin_diameter = ${pin_diameter}
    gap = 0.00095 # the half gap between sub-channel assemblies
    heated_length = 1.0
    spacer_z = '0.0'
    spacer_k = '0.0'
  []

  [fuel_pins]
    type = SCMQuadPinMeshGenerator
    input = sub_channel
    nx = 6
    ny = 6
    n_cells = 10
    pitch = 0.0126
    heated_length = 1.0
  []
[]

[FluidProperties]
  [water]
    type = Water97FluidProperties
  []
[]

[SubChannel]
  type = QuadSubChannel1PhaseProblem
  fp = water
  n_blocks = 1
  beta = 0.006
  CT = 2.6
  compute_density = true
  compute_viscosity = true
  compute_power = true
  P_out = ${P_out}
  verbose_subchannel = true
  implicit = true
  segregated = false
  monolithic_thermal = true
  staggered_pressure = true
[]

[ICs]
  [S_IC]
    type = SCMQuadFlowAreaIC
    variable = S
  []

  [w_perim_IC]
    type = SCMQuadWettedPerimIC
    variable = w_perim
  []

  [q_prime_IC]
    type = SCMQuadPowerIC
    variable = q_prime
    power = 1.0e6 # W
    filename = "power_profile.txt" #type in name of file that describes radial power profile
    block = fuel_pins
  []

  [T_ic]
    type = ConstantIC
    variable = T
    value = ${T_in}
  []

  [Dpin_ic]
    type = ConstantIC
    variable = Dpin
    value = ${pin_diameter}
  []

  [P_ic]
    type = ConstantIC
    variable = P
    value = 0.0
  []

  [DP_ic]
    type = ConstantIC
    variable = DP
    value = 0.0
  []

  [Viscosity_ic]
    type = ViscosityIC
    variable = mu
    p = ${P_out}
    T = T
    fp = water
  []

  [rho_ic]
    type = RhoFromPressureTemperatureIC
    variable = rho
    p = ${P_out}
    T = T
    fp = water
  []

  [h_ic]
    type = SpecificEnthalpyFromPressureTemperatureIC
    variable = h
    p = ${P_out}
    T = T
    fp = water
  []

  [mdot_ic]
    type = ConstantIC
    variable = mdot
    value = 0.0
  []
[]

[AuxKernels]
  [T_in_bc]
    type = ConstantAux
    variable = T
    boundary = inlet
    value = ${T_in}
    execute_on = 'timestep_begin'
    block = sub_channel
  []
  [mdot_in_bc]
    type = SCMMassFlowRateAux
    variable = mdot
    boundary = inlet
    area = S
    mass_flux = report_mass_flux_inlet
    execute_on = 'timestep_begin'
    block = sub_channel
  []
[]

[Postprocessors]
  [report_mass_flux_inlet]
    type = Receiver
    default = ${mass_flux_in}
  []
  [total_pressure_drop]
    type = SubChannelDelta
    variable = P
    execute_on = "timestep_end"
  []
  [T1]
    type = SubChannelPointValue
    variable = T
    index = 0
    execute_on = "timestep_end"
    height = 1
  []
  [T2]
    type = SubChannelPointValue
    variable = T
    index = 7
    execute_on = "timestep_end"
    height = 1
  []
  [T3]
    type = SubChannelPointValue
    variable = T
    index = 14
    execute_on = "timestep_end"
    height = 1
  []
  [T4]
    type = SubChannelPointValue
    variable = T
    index = 21
    execute_on = "timestep_end"
    height = 1
  []
  [T5]
    type = SubChannelPointValue
    variable = T
    index = 28
    execute_on = "timestep_end"
    height = 1
  []
  [T6]
    type = SubChannelPointValue
    variable = T
    index = 35
    execute_on = "timestep_end"
    height = 1
  []
[]

[Outputs]
  csv = true
[]

[Executioner]
  type = Steady
[]

(modules/subchannel/validation/Blockage/PNNL_7x7/7X7blockage70.i)

T_in = 302.594
mass_flux_in = 1730.0950134985335
P_out = 101325 # Pa
# Creer et. al 1976
# Blockage is modeled with area reduction and form loss coefficient distributed on the
# affected subchannels

[QuadSubChannelMesh]
  [sub_channel]
    type = SCMQuadSubChannelMeshGenerator
    nx = 8
    ny = 8
    n_cells = 36
    pitch = 0.0136906
    Kij = 0.5
    pin_diameter = 0.0099568
    gap = 0.0036957
    heated_length = 1.4224
    z_blockage = '0.60325 0.67945'
    index_blockage = '18 19 20 21 26 27 28 29 34 35 36 37 42 43 44 45'
    reduction_blockage = '0.83 0.65 0.65 0.83 0.65 0.30 0.30 0.65 0.65 0.30 0.30 0.65 0.83 0.65 0.65 0.83'
    k_blockage = '0.0 0.0 0.0 0.0 0.0 1 1 0.0 0.0 1 1 0.0 0.0 0.0 0.0 0.0'
    spacer_z = '0.3683 1.3843'
    spacer_k = '1.14 1.14'
  []
[]

[AuxVariables]
  [mdot]
    block = sub_channel
  []
  [SumWij]
    block = sub_channel
  []
  [P]
    block = sub_channel
  []
  [DP]
    block = sub_channel
  []
  [h]
    block = sub_channel
  []
  [T]
    block = sub_channel
  []
  [rho]
    block = sub_channel
  []
  [mu]
    block = sub_channel
  []
  [S]
    block = sub_channel
  []
  [w_perim]
    block = sub_channel
  []
[]

[FluidProperties]
  [water]
    type = Water97FluidProperties
  []
[]

[SubChannel]
  type = QuadSubChannel1PhaseProblem
  fp = water
  n_blocks = 1
  beta = 0.06
  CT = 2.6
  compute_density = true
  compute_viscosity = true
  compute_power = false
  P_out = ${P_out}
  implicit = true
  segregated = false
  staggered_pressure = false
  monolithic_thermal = false
  interpolation_scheme = 'upwind'
[]

[ICs]
  [S_IC]
    type = SCMQuadFlowAreaIC
    variable = S
  []

  [w_perim_IC]
    type = SCMQuadWettedPerimIC
    variable = w_perim
  []

  [q_prime_IC]
    type = SCMQuadPowerIC
    variable = q_prime
    power = 0.0 # W
    filename = "power_profile.txt"
  []

  [T_ic]
    type = ConstantIC
    variable = T
    value = ${T_in}
  []

  [P_ic]
    type = ConstantIC
    variable = P
    value = 0.0
  []

  [DP_ic]
    type = ConstantIC
    variable = DP
    value = 0.0
  []

  [Viscosity_ic]
    type = ViscosityIC
    variable = mu
    p = ${P_out}
    T = T
    fp = water
  []

  [rho_ic]
    type = RhoFromPressureTemperatureIC
    variable = rho
    p = ${P_out}
    T = T
    fp = water
  []

  [h_ic]
    type = SpecificEnthalpyFromPressureTemperatureIC
    variable = h
    p = ${P_out}
    T = T
    fp = water
  []

  [mdot_ic]
    type = ConstantIC
    variable = mdot
    value = 0.0
  []
[]

[AuxKernels]
  [T_in_bc]
    type = ConstantAux
    variable = T
    boundary = inlet
    value = ${T_in}
    execute_on = 'timestep_begin'
  []
  [mdot_in_bc]
    type = SCMMassFlowRateAux
    variable = mdot
    boundary = inlet
    area = S
    mass_flux = ${mass_flux_in}
    execute_on = 'timestep_begin'
  []
[]

[Outputs]
  exodus = true
[]

[Executioner]
  type = Steady
[]

[MultiApps]
  [viz]
    type = FullSolveMultiApp
    input_files = "detailedMesh.i"
    execute_on = "final"
  []
[]

[Transfers]
  ###### Transfers to the detailedMesh at the end of the coupled simulations
  [subchannel_transfer]
    type = SCMSolutionTransfer
    to_multi_app = viz
    variable = 'mdot SumWij P DP h T rho mu S'
  []
[]

(modules/subchannel/test/tests/restart/steady.i)

T_in = 359.15
# [1e+6 kg/m^2-hour] turns into kg/m^2-sec
mass_flux_in = '${fparse 1e+6 * 17.00 / 3600.}'
P_out = 4.923e6 # Pa

[QuadSubChannelMesh]
  [sub_channel]
    type = SCMQuadSubChannelMeshGenerator
    nx = 3
    ny = 3
    n_cells = 10
    pitch = 0.0126
    pin_diameter = 0.00950
    gap = 0.00095 # the half gap between sub-channel assemblies
    heated_length = 1
    spacer_z = '0.0'
    spacer_k = '0.0'
  []
[]

[FluidProperties]
  [water]
    type = Water97FluidProperties
  []
[]

[SubChannel]
  type = QuadSubChannel1PhaseProblem
  fp = water
  n_blocks = 1
  beta = 0.006
  CT = 1.8
  compute_density = true
  compute_viscosity = true
  compute_power = true
  P_out = ${P_out}
[]

[ICs]
  [S_ic]
    type = SCMQuadFlowAreaIC
    variable = S
  []

  [w_perim_ic]
    type = SCMQuadWettedPerimIC
    variable = w_perim
  []

  [q_prime_ic]
    type = SCMQuadPowerIC
    variable = q_prime
    power = 1e6
    filename = "power_profile.txt"
  []

  [T_ic]
    type = ConstantIC
    variable = T
    value = ${T_in}
  []

  [P_ic]
    type = ConstantIC
    variable = P
    value = 0.0
  []

  [DP_ic]
    type = ConstantIC
    variable = DP
    value = 0.0
  []

  [rho_ic]
    type = RhoFromPressureTemperatureIC
    variable = rho
    p = ${P_out}
    T = T
    fp = water
  []

  [h_ic]
    type = SpecificEnthalpyFromPressureTemperatureIC
    variable = h
    p = ${P_out}
    T = T
    fp = water
  []

  [mdot_ic]
    type = ConstantIC
    variable = mdot
    value = 0.0
  []
[]

[AuxKernels]
  [T_in_bc]
    type = ConstantAux
    variable = T
    boundary = inlet
    value = ${T_in}
    execute_on = 'timestep_begin'
  []
  [mdot_in_bc]
    type = SCMMassFlowRateAux
    variable = mdot
    boundary = inlet
    area = S
    mass_flux = ${mass_flux_in}
    execute_on = 'timestep_begin'
  []
[]

[Outputs]
  exodus = true
  checkpoint = true
[]

[Executioner]
  type = Steady
[]

(modules/subchannel/validation/PNNL_12_pin/steady_state/2X6_ss.i)

[GlobalParams]
  ######## Geometry #
  nx = 7
  ny = 3
  n_cells = 48
  n_blocks = 1
  pitch = 0.014605
  pin_diameter = 0.012065
  gap = 0.0015875
  heated_length = 1.2192
  spacer_z = '0.0'
  spacer_k = '0.0'
[]

######## BC's #################
T_in = 297.039 # K
P_out = 101325 # Pa

[QuadSubChannelMesh]
  [sub_channel]
    type = SCMQuadSubChannelMeshGenerator
  []

  [fuel_pins]
    type = SCMQuadPinMeshGenerator
    input = sub_channel
  []
[]

[AuxVariables]
  [mdot]
    block = sub_channel
  []
  [SumWij]
    block = sub_channel
  []
  [P]
    block = sub_channel
  []
  [DP]
    block = sub_channel
  []
  [h]
    block = sub_channel
  []
  [T]
    block = sub_channel
  []
  [Tpin]
    block = fuel_pins
  []
  [Dpin]
    block = fuel_pins
  []
  [rho]
    block = sub_channel
  []
  [mu]
    block = sub_channel
  []
  [S]
    block = sub_channel
  []
  [w_perim]
    block = sub_channel
  []
  [q_prime]
    block = fuel_pins
  []
[]

[FluidProperties]
  [water]
    type = Water97FluidProperties
  []
[]

[SubChannel]
  type = QuadSubChannel1PhaseProblem
  fp = water
  beta = 0.006
  CT = 2.6
  P_tol = 1e-6
  T_tol = 1e-6
  compute_density = true
  compute_viscosity = true
  compute_power = true
  P_out = ${P_out}
  implicit = true
  segregated = false
  monolithic_thermal = false
[]

[ICs]
  [S_IC]
    type = SCMQuadFlowAreaIC
    variable = S
  []

  [w_perim_IC]
    type = SCMQuadWettedPerimIC
    variable = w_perim
  []

  [q_prime_IC]
    type = SCMQuadPowerIC
    variable = q_prime
    power = 5460 # W
    filename = "power_profile.txt"
  []

  [T_ic]
    type = ConstantIC
    variable = T
    value = ${T_in}
  []

  [Dpin_ic]
    type = ConstantIC
    variable = Dpin
    value = 0.012065
  []

  [P_ic]
    type = ConstantIC
    variable = P
    value = 0.0
  []

  [DP_ic]
    type = ConstantIC
    variable = DP
    value = 0.0
  []

  [Viscosity_ic]
    type = ViscosityIC
    variable = mu
    p = ${P_out}
    T = T
    fp = water
  []

  [rho_ic]
    type = RhoFromPressureTemperatureIC
    variable = rho
    p = ${P_out}
    T = T
    fp = water
  []

  [h_ic]
    type = SpecificEnthalpyFromPressureTemperatureIC
    variable = h
    p = ${P_out}
    T = T
    fp = water
  []

  [mdot_ic]
    type = ConstantIC
    variable = mdot
    value = 0.0
  []
[]

[AuxKernels]
  [T_in_bc]
    type = ConstantAux
    variable = T
    boundary = inlet
    value = ${T_in}
    execute_on = 'timestep_begin'
  []
  [mdot_in_bc]
    type = SCMMassFlowRateAux
    variable = mdot
    boundary = inlet
    area = S
    mass_flux = 131.43435930715006
    execute_on = 'timestep_begin'
  []
[]

[Outputs]
  exodus = true
  csv = true
  [mdot_in_MATRIX]
    type = QuadSubChannelNormalSliceValues
    variable = mdot
    execute_on = final
    file_base = "mdot_in.txt"
    height = 0.0
  []

  [rho_in_MATRIX]
    type = QuadSubChannelNormalSliceValues
    variable = rho
    execute_on = final
    file_base = "rho_in.txt"
    height = 0.0
  []

  [mdot_out_MATRIX]
    type = QuadSubChannelNormalSliceValues
    variable = mdot
    execute_on = final
    file_base = "mdot_out.txt"
    height = 1.2192
  []

  [rho_out_MATRIX]
    type = QuadSubChannelNormalSliceValues
    variable = rho
    execute_on = final
    file_base = "rho_out.txt"
    height = 1.2192
  []

  [mdot_MATRIX]
    type = QuadSubChannelNormalSliceValues
    variable = mdot
    execute_on = final
    file_base = "mdot_075.txt"
    height = 0.9144
  []

  [T_in_MATRIX]
    type = QuadSubChannelNormalSliceValues
    variable = T
    execute_on = final
    file_base = "T_in.txt"
    height = 0.0
  []

  [T_out_MATRIX]
    type = QuadSubChannelNormalSliceValues
    variable = T
    execute_on = final
    file_base = "T_out.txt"
    height = 1.2192
  []
[]

[Postprocessors]
  [mdot7]
    type = SubChannelPointValue
    variable = mdot
    index = 7
    execute_on = 'initial timestep_end'
    height = 0.9144
  []
  [mdot8]
    type = SubChannelPointValue
    variable = mdot
    index = 8
    execute_on = 'initial timestep_end'
    height = 0.9144
  []
  [mdot9]
    type = SubChannelPointValue
    variable = mdot
    index = 9
    execute_on = 'initial timestep_end'
    height = 0.9144
  []
  [mdot10]
    type = SubChannelPointValue
    variable = mdot
    index = 10
    execute_on = 'initial timestep_end'
    height = 0.9144
  []
  [mdot11]
    type = SubChannelPointValue
    variable = mdot
    index = 11
    execute_on = 'initial timestep_end'
    height = 0.9144
  []
  [mdot12]
    type = SubChannelPointValue
    variable = mdot
    index = 12
    execute_on = 'initial timestep_end'
    height = 0.9144
  []
  [mdot13]
    type = SubChannelPointValue
    variable = mdot
    index = 13
    execute_on = 'initial timestep_end'
    height = 0.9144
  []
[]

[Executioner]
  type = Steady
[]

################################################################################
# A multiapp that projects data to a detailed mesh
################################################################################

[MultiApps]
  [viz]
    type = FullSolveMultiApp
    input_files = "3d.i"
    execute_on = "timestep_end"
  []
[]

###### Transfers to the detailedMesh at the end of the coupled simulations
[Transfers]
  [subchannel_transfer]
    type = SCMSolutionTransfer
    to_multi_app = viz
    variable = 'mdot SumWij P DP h T rho mu S'
  []
  [pin_transfer]
    type = SCMPinSolutionTransfer
    to_multi_app = viz
    variable = 'Tpin q_prime'
  []
[]

(modules/subchannel/test/tests/problems/psbt/psbt_explicit.i)

T_in = 359.15
# [1e+6 kg/m^2-hour] turns into kg/m^2-sec
mass_flux_in = '${fparse 1e+6 * 17.00 / 3600.}'
P_out = 4.923e6 # Pa
pin_diameter = 0.00950

[QuadSubChannelMesh]
  [sub_channel]
    type = SCMQuadSubChannelMeshGenerator
    nx = 6
    ny = 6
    n_cells = 10
    pitch = 0.0126
    pin_diameter = ${pin_diameter}
    gap = 0.00095 # the half gap between sub-channel assemblies
    heated_length = 1.0
    spacer_z = '0.0'
    spacer_k = '0.0'
  []

  [fuel_pins]
    type = SCMQuadPinMeshGenerator
    input = sub_channel
    nx = 6
    ny = 6
    n_cells = 10
    pitch = 0.0126
    heated_length = 1.0
  []
[]

[FluidProperties]
  [water]
    type = Water97FluidProperties
  []
[]

[SubChannel]
  type = QuadSubChannel1PhaseProblem
  fp = water
  n_blocks = 1
  beta = 0.006
  CT = 2.6
  compute_density = true
  compute_viscosity = true
  compute_power = true
  P_out = ${P_out}
  verbose_subchannel = true
[]

[ICs]
  [S_IC]
    type = SCMQuadFlowAreaIC
    variable = S
  []

  [w_perim_IC]
    type = SCMQuadWettedPerimIC
    variable = w_perim
  []

  [q_prime_IC]
    type = SCMQuadPowerIC
    variable = q_prime
    power = 1.0e6 # W
    filename = "power_profile.txt" #type in name of file that describes radial power profile
    block = fuel_pins
  []

  [T_ic]
    type = ConstantIC
    variable = T
    value = ${T_in}
  []

  [Dpin_ic]
    type = ConstantIC
    variable = Dpin
    value = ${pin_diameter}
  []

  [P_ic]
    type = ConstantIC
    variable = P
    value = 0.0
  []

  [DP_ic]
    type = ConstantIC
    variable = DP
    value = 0.0
  []

  [Viscosity_ic]
    type = ViscosityIC
    variable = mu
    p = ${P_out}
    T = T
    fp = water
  []

  [rho_ic]
    type = RhoFromPressureTemperatureIC
    variable = rho
    p = ${P_out}
    T = T
    fp = water
  []

  [h_ic]
    type = SpecificEnthalpyFromPressureTemperatureIC
    variable = h
    p = ${P_out}
    T = T
    fp = water
  []

  [mdot_ic]
    type = ConstantIC
    variable = mdot
    value = 0.0
  []
[]

[AuxKernels]
  [T_in_bc]
    type = ConstantAux
    variable = T
    boundary = inlet
    value = ${T_in}
    execute_on = 'timestep_begin'
    block = sub_channel
  []
  [mdot_in_bc]
    type = SCMMassFlowRateAux
    variable = mdot
    boundary = inlet
    area = S
    mass_flux = report_mass_flux_inlet
    execute_on = 'timestep_begin'
    block = sub_channel
  []
[]

[Postprocessors]
  [report_mass_flux_inlet]
    type = Receiver
    default = ${mass_flux_in}
  []
  [total_pressure_drop]
    type = SubChannelDelta
    variable = P
    execute_on = "timestep_end"
  []
  [T1]
    type = SubChannelPointValue
    variable = T
    index = 0
    execute_on = "timestep_end"
    height = 1
  []
  [T2]
    type = SubChannelPointValue
    variable = T
    index = 7
    execute_on = "timestep_end"
    height = 1
  []
  [T3]
    type = SubChannelPointValue
    variable = T
    index = 14
    execute_on = "timestep_end"
    height = 1
  []
  [T4]
    type = SubChannelPointValue
    variable = T
    index = 21
    execute_on = "timestep_end"
    height = 1
  []
  [T5]
    type = SubChannelPointValue
    variable = T
    index = 28
    execute_on = "timestep_end"
    height = 1
  []
  [T6]
    type = SubChannelPointValue
    variable = T
    index = 35
    execute_on = "timestep_end"
    height = 1
  []
[]

[Outputs]
  csv = true
[]

[Executioner]
  type = Steady
[]

(modules/subchannel/test/tests/problems/psbt/psbt_full_monolithic.i)

T_in = 359.15
# [1e+6 kg/m^2-hour] turns into kg/m^2-sec
mass_flux_in = '${fparse 1e+6 * 17.00 / 3600.}'
P_out = 4.923e6 # Pa
pin_diameter = 0.00950

[QuadSubChannelMesh]
  [sub_channel]
    type = SCMQuadSubChannelMeshGenerator
    nx = 6
    ny = 6
    n_cells = 10
    pitch = 0.0126
    pin_diameter = ${pin_diameter}
    gap = 0.00095 # the half gap between sub-channel assemblies
    heated_length = 1.0
    spacer_z = '0.0'
    spacer_k = '0.0'
  []

  [fuel_pins]
    type = SCMQuadPinMeshGenerator
    input = sub_channel
    nx = 6
    ny = 6
    n_cells = 10
    pitch = 0.0126
    heated_length = 1.0
  []
[]

[FluidProperties]
  [water]
    type = Water97FluidProperties
  []
[]

[SubChannel]
  type = QuadSubChannel1PhaseProblem
  fp = water
  n_blocks = 1
  beta = 0.006
  CT = 2.6
  compute_density = true
  compute_viscosity = true
  compute_power = true
  P_out = ${P_out}
  verbose_subchannel = true
  implicit = true
  segregated = false
  monolithic_thermal = true
[]

[ICs]
  [S_IC]
    type = SCMQuadFlowAreaIC
    variable = S
  []

  [w_perim_IC]
    type = SCMQuadWettedPerimIC
    variable = w_perim
  []

  [q_prime_IC]
    type = SCMQuadPowerIC
    variable = q_prime
    power = 1.0e6 # W
    filename = "power_profile.txt" #type in name of file that describes radial power profile
    block = fuel_pins
  []

  [T_ic]
    type = ConstantIC
    variable = T
    value = ${T_in}
  []

  [Dpin_ic]
    type = ConstantIC
    variable = Dpin
    value = ${pin_diameter}
  []

  [P_ic]
    type = ConstantIC
    variable = P
    value = 0.0
  []

  [DP_ic]
    type = ConstantIC
    variable = DP
    value = 0.0
  []

  [Viscosity_ic]
    type = ViscosityIC
    variable = mu
    p = ${P_out}
    T = T
    fp = water
  []

  [rho_ic]
    type = RhoFromPressureTemperatureIC
    variable = rho
    p = ${P_out}
    T = T
    fp = water
  []

  [h_ic]
    type = SpecificEnthalpyFromPressureTemperatureIC
    variable = h
    p = ${P_out}
    T = T
    fp = water
  []

  [mdot_ic]
    type = ConstantIC
    variable = mdot
    value = 0.0
  []
[]

[AuxKernels]
  [T_in_bc]
    type = ConstantAux
    variable = T
    boundary = inlet
    value = ${T_in}
    execute_on = 'timestep_begin'
    block = sub_channel
  []
  [mdot_in_bc]
    type = SCMMassFlowRateAux
    variable = mdot
    boundary = inlet
    area = S
    mass_flux = report_mass_flux_inlet
    execute_on = 'timestep_begin'
    block = sub_channel
  []
[]

[Postprocessors]
  [report_mass_flux_inlet]
    type = Receiver
    default = ${mass_flux_in}
  []
  [total_pressure_drop]
    type = SubChannelDelta
    variable = P
    execute_on = "timestep_end"
  []
  [T1]
    type = SubChannelPointValue
    variable = T
    index = 0
    execute_on = "timestep_end"
    height = 1
  []
  [T2]
    type = SubChannelPointValue
    variable = T
    index = 7
    execute_on = "timestep_end"
    height = 1
  []
  [T3]
    type = SubChannelPointValue
    variable = T
    index = 14
    execute_on = "timestep_end"
    height = 1
  []
  [T4]
    type = SubChannelPointValue
    variable = T
    index = 21
    execute_on = "timestep_end"
    height = 1
  []
  [T5]
    type = SubChannelPointValue
    variable = T
    index = 28
    execute_on = "timestep_end"
    height = 1
  []
  [T6]
    type = SubChannelPointValue
    variable = T
    index = 35
    execute_on = "timestep_end"
    height = 1
  []
[]

[Outputs]
  csv = true
[]

[Executioner]
  type = Steady
[]

(modules/subchannel/test/tests/problems/coupling/main.i)

T_in = 297.039 # K
P_out = 101325 # Pa
heated_length = 1.0

[QuadSubChannelMesh]
  [sub_channel]
    type = SCMQuadSubChannelMeshGenerator
    nx = 2
    ny = 2
    n_cells = 10
    pitch = 0.014605
    pin_diameter = 0.012065
    gap = 0.0015875
    heated_length = ${heated_length}
    spacer_z = '0.0'
    spacer_k = '0.0'
  []

  [fuel_pins]
    type = SCMQuadPinMeshGenerator
    input = sub_channel
    nx = 2
    ny = 2
    n_cells = 10
    pitch = 0.014605
    heated_length = ${heated_length}
  []
[]

[AuxVariables]
  [mdot]
    block = sub_channel
  []
  [SumWij]
    block = sub_channel
  []
  [P]
    block = sub_channel
  []
  [DP]
    block = sub_channel
  []
  [h]
    block = sub_channel
  []
  [T]
    block = sub_channel
  []
  [Tpin]
    block = fuel_pins
  []
  [Dpin]
    block = fuel_pins
  []
  [rho]
    block = sub_channel
  []
  [mu]
    block = sub_channel
  []
  [S]
    block = sub_channel
  []
  [w_perim]
    block = sub_channel
  []
  [q_prime]
    block = fuel_pins
  []
  [displacement]
    block = sub_channel
  []
[]

[FluidProperties]
  [water]
    type = Water97FluidProperties
  []
[]

[Functions]
  [axial_heat_rate]
    type = ParsedFunction
    expression = '(pi/2)*sin(pi*z/L)'
    symbol_names = 'L'
    symbol_values = '${heated_length}'
  []
[]

[SubChannel]
  type = QuadSubChannel1PhaseProblem
  n_blocks = 1
  fp = water
  beta = 0.006
  CT = 2.6
  compute_density = true
  compute_viscosity = true
  compute_power = true
  P_out = ${P_out}
[]

[ICs]
  [S_IC]
    type = SCMQuadFlowAreaIC
    variable = S
  []

  [w_perim_IC]
    type = SCMQuadWettedPerimIC
    variable = w_perim
  []

  [q_prime_IC]
    type = SCMQuadPowerIC
    variable = q_prime
    power = 1000 # W
    filename = "power_profile.txt"
    axial_heat_rate = axial_heat_rate
  []

  [T_ic]
    type = ConstantIC
    variable = T
    value = ${T_in}
  []

  [Dpin_ic]
    type = ConstantIC
    variable = Dpin
    value = 0.012065
  []

  [P_ic]
    type = ConstantIC
    variable = P
    value = 0.0
  []

  [DP_ic]
    type = ConstantIC
    variable = DP
    value = 0.0
  []

  [Viscosity_ic]
    type = ViscosityIC
    variable = mu
    p = ${P_out}
    T = T
    fp = water
  []

  [rho_ic]
    type = RhoFromPressureTemperatureIC
    variable = rho
    p = ${P_out}
    T = T
    fp = water
  []

  [h_ic]
    type = SpecificEnthalpyFromPressureTemperatureIC
    variable = h
    p = ${P_out}
    T = T
    fp = water
  []

  [mdot_ic]
    type = ConstantIC
    variable = mdot
    value = 0.0
  []
[]

[AuxKernels]
  [T_in_bc]
    type = ConstantAux
    variable = T
    boundary = inlet
    value = ${T_in}
    execute_on = 'timestep_begin'
  []
  [mdot_in_bc]
    type = SCMMassFlowRateAux
    variable = mdot
    boundary = inlet
    area = S
    mass_flux = 131.43435930715006
    execute_on = 'timestep_begin'
  []
[]

[Outputs]
  exodus = true
[]

[Executioner]
  type = Steady
  petsc_options_iname = '-pc_type -pc_hypre_type'
  petsc_options_value = 'hypre boomeramg'
  fixed_point_max_its = 30
  fixed_point_min_its = 2
  fixed_point_rel_tol = 1e-6
[]

################################################################################
# A multiapp that transfers data to heat conduction simulations
################################################################################

[MultiApps] # I have as many multiapps as pins
  [sub]
    type = FullSolveMultiApp
    input_files = sub.i # seperate file for multiapps due to radial power profile
    execute_on = 'timestep_end'
    positions = '0   0   0 '
    bounding_box_padding = '0 0 0.01'
  []
  [viz]
    type = FullSolveMultiApp
    input_files = '3d.i'
    execute_on = 'timestep_end'
  []
[]

[Transfers]
  [Tpin] # send pin surface temperature to heat conduction,
    type = MultiAppGeneralFieldNearestLocationTransfer
    to_multi_app = sub
    variable = Pin_surface_temperature
    source_variable = Tpin
    execute_on = 'timestep_end'
  []

  [from_sub] # send heat flux from heat conduction to subchannel
    type = MultiAppGeneralFieldNearestLocationTransfer
    from_multi_app = sub
    variable = q_prime
    source_variable = q_prime
    from_boundaries = right
    execute_on = 'timestep_end'
  []

  [subchannel_transfer]
    type = SCMSolutionTransfer
    to_multi_app = viz
    variable = 'mdot SumWij P DP h T rho mu S'
    execute_on = 'timestep_end'
  []

  [pin_transfer]
    type = SCMPinSolutionTransfer
    to_multi_app = viz
    variable = 'Tpin q_prime Dpin'
    execute_on = 'timestep_end'
  []
[]

(modules/subchannel/test/tests/problems/psbt/psbt_monolithic.i)

T_in = 359.15
# [1e+6 kg/m^2-hour] turns into kg/m^2-sec
mass_flux_in = '${fparse 1e+6 * 17.00 / 3600.}'
P_out = 4.923e6 # Pa
pin_diameter = 0.00950

[QuadSubChannelMesh]
  [sub_channel]
    type = SCMQuadSubChannelMeshGenerator
    nx = 6
    ny = 6
    n_cells = 10
    pitch = 0.0126
    pin_diameter = ${pin_diameter}
    gap = 0.00095 # the half gap between sub-channel assemblies
    heated_length = 1.0
    spacer_z = '0.0'
    spacer_k = '0.0'
  []

  [fuel_pins]
    type = SCMQuadPinMeshGenerator
    input = sub_channel
    nx = 6
    ny = 6
    n_cells = 10
    pitch = 0.0126
    heated_length = 1.0
  []
[]

[FluidProperties]
  [water]
    type = Water97FluidProperties
  []
[]

[SubChannel]
  type = QuadSubChannel1PhaseProblem
  fp = water
  n_blocks = 1
  beta = 0.006
  CT = 2.6
  compute_density = true
  compute_viscosity = true
  compute_power = true
  P_out = ${P_out}
  verbose_subchannel = true
  implicit = true
  segregated = false
[]

[ICs]
  [S_IC]
    type = SCMQuadFlowAreaIC
    variable = S
  []

  [w_perim_IC]
    type = SCMQuadWettedPerimIC
    variable = w_perim
  []

  [q_prime_IC]
    type = SCMQuadPowerIC
    variable = q_prime
    power = 1.0e6 # W
    filename = "power_profile.txt" #type in name of file that describes radial power profile
    block = fuel_pins
  []

  [T_ic]
    type = ConstantIC
    variable = T
    value = ${T_in}
  []

  [Dpin_ic]
    type = ConstantIC
    variable = Dpin
    value = ${pin_diameter}
  []

  [P_ic]
    type = ConstantIC
    variable = P
    value = 0.0
  []

  [DP_ic]
    type = ConstantIC
    variable = DP
    value = 0.0
  []

  [Viscosity_ic]
    type = ViscosityIC
    variable = mu
    p = ${P_out}
    T = T
    fp = water
  []

  [rho_ic]
    type = RhoFromPressureTemperatureIC
    variable = rho
    p = ${P_out}
    T = T
    fp = water
  []

  [h_ic]
    type = SpecificEnthalpyFromPressureTemperatureIC
    variable = h
    p = ${P_out}
    T = T
    fp = water
  []

  [mdot_ic]
    type = ConstantIC
    variable = mdot
    value = 0.0
  []
[]

[AuxKernels]
  [T_in_bc]
    type = ConstantAux
    variable = T
    boundary = inlet
    value = ${T_in}
    execute_on = 'timestep_begin'
    block = sub_channel
  []
  [mdot_in_bc]
    type = SCMMassFlowRateAux
    variable = mdot
    boundary = inlet
    area = S
    mass_flux = report_mass_flux_inlet
    execute_on = 'timestep_begin'
    block = sub_channel
  []
[]

[Postprocessors]
  [report_mass_flux_inlet]
    type = Receiver
    default = ${mass_flux_in}
  []
  [total_pressure_drop]
    type = SubChannelDelta
    variable = P
    execute_on = "timestep_end"
  []
  [T1]
    type = SubChannelPointValue
    variable = T
    index = 0
    execute_on = "timestep_end"
    height = 1
  []
  [T2]
    type = SubChannelPointValue
    variable = T
    index = 7
    execute_on = "timestep_end"
    height = 1
  []
  [T3]
    type = SubChannelPointValue
    variable = T
    index = 14
    execute_on = "timestep_end"
    height = 1
  []
  [T4]
    type = SubChannelPointValue
    variable = T
    index = 21
    execute_on = "timestep_end"
    height = 1
  []
  [T5]
    type = SubChannelPointValue
    variable = T
    index = 28
    execute_on = "timestep_end"
    height = 1
  []
  [T6]
    type = SubChannelPointValue
    variable = T
    index = 35
    execute_on = "timestep_end"
    height = 1
  []
[]

[Outputs]
  csv = true
[]

[Executioner]
  type = Steady
[]

(modules/subchannel/validation/PNNL_12_pin/transient/2X6_transient.i)

T_in = 297.039 # K
P_out = 101325 # Pa

[QuadSubChannelMesh]
  [sub_channel]
    type = SCMQuadSubChannelMeshGenerator
    nx = 7
    ny = 3
    n_cells = 60
    pitch = 0.014605
    pin_diameter = 0.012065
    gap = 0.0015875
    unheated_length_entry = 0.3048
    heated_length = 1.2192
    spacer_z = '0.0'
    spacer_k = '0.0'
  []
[]

[FluidProperties]
  [water]
    type = Water97FluidProperties
  []
[]

[SubChannel]
  type = QuadSubChannel1PhaseProblem
  fp = water
  n_blocks = 1
  beta = 0.006
  CT = 2.6
  P_tol = 1e-6
  T_tol = 1e-6
  compute_density = true
  compute_viscosity = true
  compute_power = false
  P_out = ${P_out}
[]

[ICs]
  [S_IC]
    type = SCMQuadFlowAreaIC
    variable = S
  []

  [w_perim_IC]
    type = SCMQuadWettedPerimIC
    variable = w_perim
  []

  [q_prime_IC]
    type = SCMQuadPowerIC
    variable = q_prime
    power = 0.0 # W
    filename = "power_profile.txt"
  []

  [T_ic]
    type = ConstantIC
    variable = T
    value = ${T_in}
  []

  [P_ic]
    type = ConstantIC
    variable = P
    value = 0.0
  []

  [DP_ic]
    type = ConstantIC
    variable = DP
    value = 0.0
  []

  [Viscosity_ic]
    type = ViscosityIC
    variable = mu
    p = ${P_out}
    T = T
    fp = water
  []

  [rho_ic]
    type = RhoFromPressureTemperatureIC
    variable = rho
    p = ${P_out}
    T = T
    fp = water
  []

  [h_ic]
    type = SpecificEnthalpyFromPressureTemperatureIC
    variable = h
    p = ${P_out}
    T = T
    fp = water
  []

  [mdot_ic]
    type = ConstantIC
    variable = mdot
    value = 0.012101767481985
  []
[]

[Functions]
  [mass_flux]
    type = PiecewiseLinear
    xy_data = '
      5.0 122.2645
      10.0 42.7926'
  []
[]

[AuxKernels]
  [T_in_bc]
    type = ConstantAux
    variable = T
    boundary = inlet
    value = ${T_in}
    execute_on = 'timestep_begin'
  []
  [mdot_in_bc]
    type = SCMMassFlowRateAux
    variable = mdot
    boundary = inlet
    area = S
    mass_flux = mass_flux_in
    execute_on = 'timestep_begin'
  []
[]

[Postprocessors]
  [mass_flux_in]
    type = FunctionValuePostprocessor
    function = mass_flux
    execute_on = 'initial timestep_end'
  []
  [mdot]
    type = SubChannelPointValue
    variable = mdot
    index = 4
    execute_on = 'initial timestep_end'
    height = 0.4953
  []

  [mdot2]
    type = SubChannelPointValue
    variable = mdot
    index = 4
    execute_on = 'initial timestep_end'
    height = 0.0
  []
[]

[Outputs]
  exodus = true
  csv = true
[]

[Executioner]
  type = Transient
  nl_rel_tol = 0.9
  l_tol = 0.9
  start_time = 0.0
  end_time = 10
  dt = 1.0
[]

################################################################################
# A multiapp that projects data to a detailed mesh
################################################################################

[MultiApps]
  [viz]
    type = TransientMultiApp
    input_files = "3d.i"
    execute_on = "timestep_end"
  []
[]

[Transfers]
  [xfer]
    type = SCMSolutionTransfer
    to_multi_app = viz
    variable = 'mdot SumWij P DP h T rho mu q_prime S'
  []
[]

(modules/subchannel/test/tests/problems/psbt/psbt_explicit_v2.i)

T_in = 359.15
# [1e+6 kg/m^2-hour] turns into kg/m^2-sec
mass_flux_in = '${fparse 1e+6 * 17.00 / 3600.}'
P_out = 4.923e6 # Pa
pin_diameter = 0.00950

[QuadSubChannelMesh]
  [sub_channel]
    type = SCMQuadSubChannelMeshGenerator
    nx = 6
    ny = 6
    n_cells = 10
    pitch = 0.0126
    pin_diameter = ${pin_diameter}
    gap = 0.00095 # the half gap between sub-channel assemblies
    heated_length = 1.0
    spacer_z = '0.0'
    spacer_k = '0.0'
  []

  [fuel_pins]
    type = SCMQuadPinMeshGenerator
    input = sub_channel
    nx = 6
    ny = 6
    n_cells = 10
    pitch = 0.0126
    heated_length = 1.0
  []
[]

[FluidProperties]
  [water]
    type = Water97FluidProperties
  []
[]

[SubChannel]
  type = QuadSubChannel1PhaseProblem
  fp = water
  n_blocks = 1
  beta = 0.006
  CT = 2.6
  compute_density = true
  compute_viscosity = true
  compute_power = true
  P_out = report_pressure_outlet
  verbose_subchannel = true
  default_friction_model = false
  constant_beta = false
[]

[ICs]
  [S_IC]
    type = SCMQuadFlowAreaIC
    variable = S
  []

  [w_perim_IC]
    type = SCMQuadWettedPerimIC
    variable = w_perim
  []

  [T_ic]
    type = ConstantIC
    variable = T
    value = ${T_in}
  []

  [Dpin_ic]
    type = ConstantIC
    variable = Dpin
    value = ${pin_diameter}
  []

  [P_ic]
    type = ConstantIC
    variable = P
    value = 0.0
  []

  [DP_ic]
    type = ConstantIC
    variable = DP
    value = 0.0
  []

  [Viscosity_ic]
    type = ViscosityIC
    variable = mu
    p = ${P_out}
    T = T
    fp = water
  []

  [rho_ic]
    type = RhoFromPressureTemperatureIC
    variable = rho
    p = ${P_out}
    T = T
    fp = water
  []

  [h_ic]
    type = SpecificEnthalpyFromPressureTemperatureIC
    variable = h
    p = ${P_out}
    T = T
    fp = water
  []

  [mdot_ic]
    type = ConstantIC
    variable = mdot
    value = 0.0
  []
[]

[AuxKernels]
  [T_in_bc]
    type = ConstantAux
    variable = T
    boundary = inlet
    value = ${T_in}
    execute_on = 'timestep_begin'
    block = sub_channel
  []
  [mdot_in_bc]
    type = SCMMassFlowRateAux
    variable = mdot
    boundary = inlet
    area = S
    mass_flux = report_mass_flux_inlet
    execute_on = 'timestep_begin'
    block = sub_channel
  []
  [q_prime_IC]
    type = SCMQuadPowerAux
    variable = q_prime
    power = 1.0e6 # W
    filename = "power_profile.txt" #type in name of file that describes radial power profile
    execute_on = 'initial timestep_begin'
  []
[]

[Postprocessors]
  [report_mass_flux_inlet]
    type = Receiver
    default = ${mass_flux_in}
  []
  [report_pressure_outlet]
    type = Receiver
    default = ${P_out}
  []
  [total_pressure_drop]
    type = SubChannelDelta
    variable = P
    execute_on = "timestep_end"
  []
  [T1]
    type = SubChannelPointValue
    variable = T
    index = 0
    execute_on = "timestep_end"
    height = 1
  []
  [T2]
    type = SubChannelPointValue
    variable = T
    index = 7
    execute_on = "timestep_end"
    height = 1
  []
  [T3]
    type = SubChannelPointValue
    variable = T
    index = 14
    execute_on = "timestep_end"
    height = 1
  []
  [T4]
    type = SubChannelPointValue
    variable = T
    index = 21
    execute_on = "timestep_end"
    height = 1
  []
  [T5]
    type = SubChannelPointValue
    variable = T
    index = 28
    execute_on = "timestep_end"
    height = 1
  []
  [T6]
    type = SubChannelPointValue
    variable = T
    index = 35
    execute_on = "timestep_end"
    height = 1
  []
[]

[Outputs]
  csv = true
  [Temp_Out_MATRIX]
    type = QuadSubChannelNormalSliceValues
    variable = T
    execute_on = final
    file_base = "Temp_Out_Explicit.txt"
    height = 1.0
  []
[]

[Executioner]
  type = Steady
[]

(modules/subchannel/examples/coupling/thermo_mech/quad/one_pin_problem.i)

######## BC's #################
T_in = 359.15
# [1e+6 kg/m^2-hour] turns into kg/m^2-sec
mass_flux_in = '${fparse 1e+6 * 17.00 / 3600.}'
P_out = 4.923e6 # Pa
heated_length = 1.0
######## Geometry #
[GlobalParams]
    nx = 2
    ny = 2
    n_cells = 25
    pitch = 0.0126
    pin_diameter = 0.00950
    gap = 0.00095
    heated_length = ${heated_length}
    spacer_z = '0.0'
    spacer_k = '0.0'
    power = 100000.0 # W
[]

[QuadSubChannelMesh]
    [subchannel]
        type = SCMQuadSubChannelMeshGenerator
    []

    [fuel_pins]
        type = SCMQuadPinMeshGenerator
        input = subchannel
    []
[]

[Functions]
    [axial_heat_rate]
        type = ParsedFunction
        expression = '(pi/2)*sin(pi*z/L)'
        symbol_names = 'L'
        symbol_values = '${heated_length}'
    []
[]

[AuxVariables]
    [mdot]
        block = subchannel
    []
    [SumWij]
        block = subchannel
    []
    [P]
        block = subchannel
    []
    [DP]
        block = subchannel
    []
    [h]
        block = subchannel
    []
    [T]
        block = subchannel
    []
    [rho]
        block = subchannel
    []
    [mu]
        block = subchannel
    []
    [S]
        block = subchannel
    []
    [w_perim]
        block = subchannel
    []
    [q_prime]
        block = fuel_pins
    []
    [Tpin]
        block = fuel_pins
    []
    [Dpin]
        block = fuel_pins
    []
[]

[FluidProperties]
    [water]
        type = Water97FluidProperties
    []
[]

[SubChannel]
    type = QuadSubChannel1PhaseProblem
    fp = water
    n_blocks = 1
    beta = 0.006
    CT = 2.6
    compute_density = true
    compute_viscosity = true
    compute_power = true
    P_out = ${P_out}
    verbose_subchannel = true
    deformation = true
[]

[ICs]
    [S_IC]
        type = SCMQuadFlowAreaIC
        variable = S
    []

    [w_perim_IC]
        type = SCMQuadWettedPerimIC
        variable = w_perim
    []

    [q_prime_IC]
        type = SCMQuadPowerIC
        variable = q_prime
        filename = "power_profile.txt"
        axial_heat_rate = axial_heat_rate
    []

    [T_ic]
        type = ConstantIC
        variable = T
        value = ${T_in}
    []

    [Dpin_ic]
        type = ConstantIC
        variable = Dpin
        value = 0.00950
    []

    [P_ic]
        type = ConstantIC
        variable = P
        value = 0.0
    []

    [DP_ic]
        type = ConstantIC
        variable = DP
        value = 0.0
    []

    [Viscosity_ic]
        type = ViscosityIC
        variable = mu
        p = ${P_out}
        T = T
        fp = water
    []

    [rho_ic]
        type = RhoFromPressureTemperatureIC
        variable = rho
        p = ${P_out}
        T = T
        fp = water
    []

    [h_ic]
        type = SpecificEnthalpyFromPressureTemperatureIC
        variable = h
        p = ${P_out}
        T = T
        fp = water
    []

    [mdot_ic]
        type = ConstantIC
        variable = mdot
        value = 0.0
    []
[]

[AuxKernels]
    [T_in_bc]
        type = ConstantAux
        variable = T
        boundary = inlet
        value = ${T_in}
        execute_on = 'timestep_begin'
    []
    [mdot_in_bc]
        type = SCMMassFlowRateAux
        variable = mdot
        boundary = inlet
        area = S
        mass_flux = ${mass_flux_in}
        execute_on = 'timestep_begin'
    []
[]

[Outputs]
    exodus = true
    [Temp_Out_MATRIX]
        type = QuadSubChannelNormalSliceValues
        variable = T
        execute_on = final
        file_base = "Temp_Out.txt"
        height = 1.0
    []
    [mdot_Out_MATRIX]
        type = QuadSubChannelNormalSliceValues
        variable = mdot
        execute_on = final
        file_base = "mdot_Out.txt"
        height = 1.0
    []
    [mdot_In_MATRIX]
        type = QuadSubChannelNormalSliceValues
        variable = mdot
        execute_on = final
        file_base = "mdot_In.txt"
        height = 0.0
    []
[]

[Executioner]
    type = Steady
    petsc_options_iname = '-pc_type -pc_hypre_type'
    petsc_options_value = 'hypre boomeramg'
    fixed_point_max_its = 8
    fixed_point_min_its = 6
    fixed_point_rel_tol = 1e-6
[]

################################################################################
[MultiApps]
    ################################################################################
    # Couple to Thermo-Mechanical Pin model (uses kernels available in MOOSE)
    ################################################################################
    [sub]
        type = FullSolveMultiApp
        input_files = one_pin_problem_sub.i
        execute_on = 'timestep_end'
        positions = '0   0   0 '
        output_in_position = true
        bounding_box_padding = '0 0 0.01'
    []

    ################################################################################
    # A multiapp that projects the solution to a detailed mesh for visualization purposes
    ################################################################################
    [viz]
        type = FullSolveMultiApp
        input_files = '3d.i'
        execute_on = 'FINAL'
    []
[]

[Transfers]
    [Tpin] # send pin surface temperature to pin model,
        type = MultiAppGeneralFieldNearestLocationTransfer
        to_multi_app = sub
        variable = Pin_surface_temperature
        source_variable = Tpin
        execute_on = 'timestep_end'
        greedy_search = true
    []

    [diameter] # send diameter information from pin model to subchannel
        type = MultiAppGeneralFieldNearestLocationTransfer
        from_multi_app = sub
        variable = Dpin
        source_variable = pin_diameter_deformed
        from_boundaries = right
        execute_on = 'timestep_end'
        greedy_search = true
    []

    [q_prime] # send heat flux from pin model to subchannel
        type = MultiAppGeneralFieldNearestLocationTransfer
        from_multi_app = sub
        variable = q_prime
        source_variable = q_prime
        from_boundaries = right
        execute_on = 'timestep_end'
        greedy_search = true
    []

    [subchannel_transfer]
        type = SCMSolutionTransfer
        to_multi_app = viz
        variable = 'mdot SumWij P DP h T rho mu S w_perim'
    []

    [pin_transfer]
        type = SCMPinSolutionTransfer
        to_multi_app = viz
        variable = 'Tpin Dpin q_prime'
    []
[]

(modules/subchannel/validation/Blockage/PNNL_7x7/7X7blockage90.i)

T_in = 302.594
mass_flux_in = 1730.0950134985335
P_out = 101325 # Pa
# Creer et. al 1976
# Blockage is modeled with area reduction and form loss coefficient distributed on the
# affected subchannels

[QuadSubChannelMesh]
  [sub_channel]
    type = SCMQuadSubChannelMeshGenerator
    nx = 8
    ny = 8
    n_cells = 84
    pitch = 0.0136906
    Kij = 0.5
    pin_diameter = 0.0099568
    gap = 0.0036957
    heated_length = 1.4224
    z_blockage = '0.60325 0.67945'
    index_blockage = '18 19 20 21 26 27 28 29 34 35 36 37 42 43 44 45'
    reduction_blockage = '0.78 0.55 0.55 0.78 0.55 0.10 0.10 0.55 0.55 0.10 0.10 0.55 0.78 0.55 0.55 0.78'
    k_blockage = '0.0 0.0 0.0 0.0 0.0 0.9 0.9 0.0 0.0 0.9 0.9 0.0 0.0 0.0 0.0 0.0'
    spacer_z = '0.4064 1.4224'
    spacer_k = '1.14 1.14'
  []
[]

[AuxVariables]
  [mdot]
    block = sub_channel
  []
  [SumWij]
    block = sub_channel
  []
  [P]
    block = sub_channel
  []
  [DP]
    block = sub_channel
  []
  [h]
    block = sub_channel
  []
  [T]
    block = sub_channel
  []
  [rho]
    block = sub_channel
  []
  [mu]
    block = sub_channel
  []
  [S]
    block = sub_channel
  []
  [w_perim]
    block = sub_channel
  []
[]

[FluidProperties]
  [water]
    type = Water97FluidProperties
  []
[]

[SubChannel]
  type = QuadSubChannel1PhaseProblem
  fp = water
  n_blocks = 1
  beta = 0.006
  CT = 2.6
  compute_density = true
  compute_viscosity = true
  compute_power = false
  P_out = ${P_out}
  implicit = true
  segregated = false
  staggered_pressure = false
  monolithic_thermal = false
  interpolation_scheme = central_difference
[]

[ICs]
  [S_IC]
    type = SCMQuadFlowAreaIC
    variable = S
  []

  [w_perim_IC]
    type = SCMQuadWettedPerimIC
    variable = w_perim
  []

  [q_prime_IC]
    type = SCMQuadPowerIC
    variable = q_prime
    power = 0.0 # W
    filename = "power_profile.txt"
  []

  [T_ic]
    type = ConstantIC
    variable = T
    value = ${T_in}
  []

  [P_ic]
    type = ConstantIC
    variable = P
    value = 0.0
  []

  [DP_ic]
    type = ConstantIC
    variable = DP
    value = 0.0
  []

  [Viscosity_ic]
    type = ViscosityIC
    variable = mu
    p = ${P_out}
    T = T
    fp = water
  []

  [rho_ic]
    type = RhoFromPressureTemperatureIC
    variable = rho
    p = ${P_out}
    T = T
    fp = water
  []

  [h_ic]
    type = SpecificEnthalpyFromPressureTemperatureIC
    variable = h
    p = ${P_out}
    T = T
    fp = water
  []

  [mdot_ic]
    type = ConstantIC
    variable = mdot
    value = 0.0
  []
[]

[AuxKernels]
  [T_in_bc]
    type = ConstantAux
    variable = T
    boundary = inlet
    value = ${T_in}
    execute_on = 'timestep_begin'
  []
  [mdot_in_bc]
    type = SCMMassFlowRateAux
    variable = mdot
    boundary = inlet
    area = S
    mass_flux = ${mass_flux_in}
    execute_on = 'timestep_begin'
  []
[]

[Outputs]
  exodus = true
[]

[Executioner]
  type = Steady
[]

[MultiApps]
  [viz]
    type = FullSolveMultiApp
    input_files = "detailedMesh.i"
    execute_on = "final"
  []
[]

[Transfers]
  ###### Transfers to the detailedMesh at the end of the coupled simulations
  [subchannel_transfer]
    type = SCMSolutionTransfer
    to_multi_app = viz
    variable = 'mdot SumWij P DP h T rho mu S'
  []
[]

(modules/subchannel/validation/psbt/psbt_ss/psbt.i)

# M. Avramova et al., 2012,
# OECD/NRC Benchmark Based on NUPEC PWR
# Sub-channel and Bundle Tests (PSBT). Volume III: Departure from Nucleate Boiling
# Case:01-5237
T_in = 502.35
# [1e+6 kg/m^2-hour] turns into kg/m^2-sec
mass_flux_in = ${fparse 1e+6 * 16.95 / 3600.}
P_out = 14.72e6 # Pa
[QuadSubChannelMesh]
  [sub_channel]
    type = SCMQuadSubChannelMeshGenerator
    nx = 6
    ny = 6
    n_cells = 20
    pitch = 0.0126
    pin_diameter = 0.00950
    gap = 0.00095
    heated_length = 3.658
    spacer_z = '0.0 0.229 0.457 0.686 0.914 1.143 1.372 1.600 1.829 2.057 2.286 2.515 2.743 2.972 3.200 3.429'
    spacer_k = '0.7 0.4 1.0 0.4 1.0 0.4 1.0 0.4 1.0 0.4 1.0 0.4 1.0 0.4 1.0 0.4'
  []

  [fuel_pins]
    type = SCMQuadPinMeshGenerator
    input = sub_channel
    nx = 6
    ny = 6
    n_cells = 20
    pitch = 0.0126
    heated_length = 3.658
  []
[]

[AuxVariables]
  [mdot]
    block = sub_channel
  []
  [SumWij]
    block = sub_channel
  []
  [P]
    block = sub_channel
  []
  [DP]
    block = sub_channel
  []
  [h]
    block = sub_channel
  []
  [T]
    block = sub_channel
  []
  [Tpin]
    block = fuel_pins
  []
  [rho]
    block = sub_channel
  []
  [mu]
    block = sub_channel
  []
  [S]
    block = sub_channel
  []
  [w_perim]
    block = sub_channel
  []
  [q_prime]
    block = fuel_pins
  []
[]

[FluidProperties]
  [water]
    type = Water97FluidProperties
  []
[]

[SubChannel]
  type = QuadSubChannel1PhaseProblem
  fp = water
  n_blocks = 1
  beta = 0.08
  CT = 2.6
  compute_density = true
  compute_viscosity = true
  compute_power = true
  P_out = ${P_out}
  implicit = true
  segregated = false
  staggered_pressure = false
  monolithic_thermal = false
  verbose_subchannel = true
  interpolation_scheme = exponential
  deformation = true # this flag allows the re-calculation of subchannel geometric parameters based on the dpin value
[]

[ICs]
  [S_IC]
    type = SCMQuadFlowAreaIC
    variable = S
  []

  [w_perim_IC]
    type = SCMQuadWettedPerimIC
    variable = w_perim
  []

  [q_prime_IC]
    type = SCMQuadPowerIC
    variable = q_prime
    power = 3.23e6 # W
    filename = "power_profile.txt"
  []

  [T_ic]
    type = ConstantIC
    variable = T
    value = ${T_in}
  []

  [Dpin_ic]
    type = ConstantIC
    variable = Dpin
    value = 0.00950
  []

  [P_ic]
    type = ConstantIC
    variable = P
    value = 0.0
  []

  [DP_ic]
    type = ConstantIC
    variable = DP
    value = 0.0
  []

  [Viscosity_ic]
    type = ViscosityIC
    variable = mu
    p = ${P_out}
    T = T
    fp = water
  []

  [rho_ic]
    type = RhoFromPressureTemperatureIC
    variable = rho
    p = ${P_out}
    T = T
    fp = water
  []

  [h_ic]
    type = SpecificEnthalpyFromPressureTemperatureIC
    variable = h
    p = ${P_out}
    T = T
    fp = water
  []

  [mdot_ic]
    type = ConstantIC
    variable = mdot
    value = 0.0
  []
[]

[AuxKernels]
  [T_in_bc]
    type = ConstantAux
    variable = T
    boundary = inlet
    value = ${T_in}
    execute_on = 'timestep_begin'
  []
  [mdot_in_bc]
    type = SCMMassFlowRateAux
    variable = mdot
    boundary = inlet
    area = S
    mass_flux = ${mass_flux_in}
    execute_on = 'timestep_begin'
  []
[]

[Outputs]
  exodus = true
  csv = true
  [Temp_Out_MATRIX]
    type = QuadSubChannelNormalSliceValues
    variable = T
    execute_on = final
    file_base = "Temp_Out.txt"
    height = 3.658
  []
  [mdot_Out_MATRIX]
    type = QuadSubChannelNormalSliceValues
    variable = mdot
    execute_on = final
    file_base = "mdot_Out.txt"
    height = 3.658
  []
  [mdot_In_MATRIX]
    type = QuadSubChannelNormalSliceValues
    variable = mdot
    execute_on = final
    file_base = "mdot_In.txt"
    height = 0.0
  []
[]

[Postprocessors]
  [total_pressure_drop]
    type = SubChannelDelta
    variable = P
    execute_on = "timestep_end"
  []
  [T1]
    type = SubChannelPointValue
    variable = T
    index = 0
    execute_on = "timestep_end"
    height = 3.658
  []
  [T2]
    type = SubChannelPointValue
    variable = T
    index = 7
    execute_on = "timestep_end"
    height = 3.658
  []
  [T3]
    type = SubChannelPointValue
    variable = T
    index = 14
    execute_on = "timestep_end"
    height = 3.658
  []
  [T4]
    type = SubChannelPointValue
    variable = T
    index = 21
    execute_on = "timestep_end"
    height = 3.658
  []
  [T5]
    type = SubChannelPointValue
    variable = T
    index = 28
    execute_on = "timestep_end"
    height = 3.658
  []
  [T6]
    type = SubChannelPointValue
    variable = T
    index = 35
    execute_on = "timestep_end"
    height = 3.658
  []
  [PinTemp]
    type = SCMPinSurfaceTemperature
    index = 10
    height = 3.658
  []
[]

[Executioner]
  type = Steady
[]

Overview
Example Input File Syntax
Input Parameters
Input Files