Subchannel coupling with openmc not recognizing TriSubChannel1PhaseProblem #31102

willschlueter · 2025-07-22T20:29:49Z

willschlueter
Jul 22, 2025

I am coupling a subchannel analysis with openmc but keep getting the following error:

*** ERROR ***
A 'TriSubChannel1PhaseProblem' is not a registered object.

If you are trying to find this object in a dynamically loaded library, make sure that
the library can be found either in your "Problem/library_path" parameter or in the
MOOSE_LIBRARY_PATH environment variable.

even though when I run the subchannel only with cardinal it runs fine. I'll attach the five files below.

SNAP_master.i:

# Example of the executing command: mpiexec -np 2 ./cardinal-opt -i common_SNAP.i SNAP_solid_xxxxx.i --n-threads=2

# geometric parameters

fuel_diameter = 0.0135                # diameter of fuel compacts (m)
fuel_to_coolant_distance = 0.01448        # distance between center of fuel compact and coolant channel (m)
height = '${units 35.56 cm -> m}'        # SNAP height of the full core (m)
unit_cell_height = '${units 35.56 cm -> m}' # segment height, default is total.

# material parameters

fluid_density = 669.92                   # coolant density (kg/m3)
fluid_Cp = 873.0                        # fluid isobaric specific heat (J/kg/K)

gap_k = 0.3271                           # He gap thermal conductivity (W/m/K)
clad_k = 20.3                            # Clad thermal conductivity (W/m/K)
ceramic_k = 1.731                        # Ceramic thermal conductivity (W/m/K)
fuel_k = 38.31                           # fuel thermal conductivity (W/m/K)
reflector_k = 216.0                        # Be Reflector thermal conductivity (W/m/K)

# operating conditions for the full core

inlet_T = 860.0                         # inlet fluid temperature (K)
power = 6.0e+05                         # total power (W) / higher power than SNAP to compensate the 60% loss
mdot = 6.15                            # total fluid mass flowrate (kg/s) 
outlet_P = 253727.1                     # fluid outlet pressure (Pa)

# other full core specifications used to construct the unit cell model

n_fuel_pins = 211          # number of fuel compacts per assembly
																
num_layers_for_plots = 20                # number of averaging layers for making plots
num_layers_for_THM = 20
num_layers = 20 

#density_blocks = 'coolant'
#temperature_blocks = 'Fuel Ceramic GAPHE Clad Reflector'
fuel_blocks = 'Fuel'
#Reflector = 'inner_reflector inner_reflector_trim outer_reflector outer_reflector_trim'

[Mesh]
  [solid]
   type = FileMeshGenerator
   file = SNAP_mesh_9_in.e # no reflector region in the MOOSE model
  []
[]

[AuxVariables]
  [cell_temperature]
    family = MONOMIAL
    order = CONSTANT
  []
[]

[AuxKernels]
  [cell_temperature]
    type = CellTemperatureAux
    variable = cell_temperature
  []
[]

[ICs]
  [temp]
    type = FunctionIC
    variable = temp
    function = temp_ic
  []
  [heat_source]
    type = ConstantIC
    variable = heat_source
    block = ${fuel_blocks}
    value = ${fparse power / ((n_fuel_pins) * ( pi * fuel_diameter * fuel_diameter * unit_cell_height / 4.0 ))}
  []
[]

[Functions]
  [temp_ic]
    type = ParsedFunction
    expression = '${inlet_T} + (${height} - z) / ${height} * ${power} / ${mdot} / ${fluid_Cp}'
  []
[]

[Problem]
  type = OpenMCCellAverageProblem

  #identical_cell_fills = 'Fuel'
  check_tally_sum = false

  power = ${power}
  scaling = 100.0

  relaxation = constant
  relaxation_factor = 0.5

  # to get a faster-running tutorial, we use only 1000 particles per batch; converged
  # results are instead obtained by increasing this parameter to 10000. We also use fewer
  # batches to speed things up; the converged results were obtained with 500 inactive batches
  # and 2000 active batches
  particles = 20000
  inactive_batches = 100
  batches = 300
  lowest_cell_level = '1' # feedback on first level (level 0 is lattice, so we want cells within)
  source_rate_normalization = 'kappa_fission' # normalization for flux tally

  # we will read temperature from THM (for the fluid) and MOOSE (for the solid)
  # into variables we name as 'solid_temp' and 'thm_temp'. This syntax will automatically
  # create those variabes for us
  temperature_blocks =    'Fuel Ceramic GAPHE Clad'

  [Tallies]
    [heat_source]
      type = CellTally
      check_equal_mapped_tally_volumes = false
      block = 'Fuel Ceramic GAPHE Clad'
      name = heat_source
      output = 'unrelaxed_tally_std_dev'
    []
  []
[]

[MultiApps]
  # Heat conduction model
  [htm] 
    type = FullSolveMultiApp
    #type = TransientMultiApp
    app_type = CardinalApp
    input_files = SNAP_solid_8.i
    execute_on = timestep_end
  []
[]

[Transfers]
  [temperature_to_master]
    type = MultiAppGeneralFieldShapeEvaluationTransfer
    from_multi_app = htm
    variable = temp
    source_variable = T
  []
  [source_to_htm]
    type = MultiAppGeneralFieldShapeEvaluationTransfer
    source_variable = heat_source
    variable = power
    to_multi_app = htm
    from_postprocessors_to_be_preserved = heat_source
    to_postprocessors_to_be_preserved = power
  []
[]

[Postprocessors]
  [heat_source]
    type = ElementIntegralVariablePostprocessor
    variable = heat_source
    execute_on = 'transfer initial timestep_end'
  []
  [max_tally_rel_err]
    type = TallyRelativeError
    value_type = max
  []
  [max_power]
    type = ElementExtremeValue
    variable = heat_source
    value_type = max
    block = ${fuel_blocks}
  []
  [min_power]
    type = ElementExtremeValue
    variable = heat_source
    value_type = min
    block = ${fuel_blocks}
  []
  [k]
    type = KEigenvalue
  []
  #[k_std_dev]
  #  type = KStandardDeviation
  #[]
[]

[UserObjects]
  [avg_power]
    type = NearestPointLayeredAverage
    variable = heat_source
    points = '0.0 0.0 0.0'
    num_layers = ${num_layers_for_THM}
    direction = z
    block = ${fuel_blocks}
  []
  [avg_std_dev]
    type = NearestPointLayeredAverage
    variable = heat_source_std_dev
    points = '0.0 0.0 0.0'
    num_layers = ${num_layers_for_THM}
    direction = z
    block = ${fuel_blocks}
  []
[]

[VectorPostprocessors]
  [avg_q]
    type = SpatialUserObjectVectorPostprocessor
    userobject = avg_power
  []
  [stdev]
    type = SpatialUserObjectVectorPostprocessor
    userobject = avg_std_dev
  []
[]

[Executioner]
  #type = Transient
  #num_steps = 1000
  type = Steady
[]

[Outputs]
  exodus = true
  print_linear_residuals = false
  [csv]
    type = CSV
    file_base = 'csv_SNAP/SNAP'
  []
[]

SNAP_solid_8.i:

# Example of the executing command: mpiexec -np 2 ./cardinal-opt -i common_SNAP.i SNAP_solid_xxxxx.i --n-threads=2

# geometric parameters

fuel_diameter = 0.0135                # diameter of fuel compacts (m)
fuel_to_coolant_distance = 0.01448        # distance between center of fuel compact and coolant channel (m)
height = '${units 35.56 cm -> m}'        # SNAP height of the full core (m)
unit_cell_height = '${units 35.56 cm -> m}' # segment height, default is total.

# material parameters

fluid_density = 669.92                   # coolant density (kg/m3)
fluid_Cp = 873.0                        # fluid isobaric specific heat (J/kg/K)

gap_k = 0.3271                           # He gap thermal conductivity (W/m/K)
clad_k = 20.3                            # Clad thermal conductivity (W/m/K)
ceramic_k = 1.731                        # Ceramic thermal conductivity (W/m/K)
fuel_k = 38.31                           # fuel thermal conductivity (W/m/K)
reflector_k = 216.0                        # Be Reflector thermal conductivity (W/m/K)

# operating conditions for the full core

inlet_T = 860.0                         # inlet fluid temperature (K)
power = 6.0e+05                         # total power (W)
mdot = 6.15                            # total fluid mass flowrate (kg/s) 
outlet_P = 253727.1                     # fluid outlet pressure (Pa)

# other full core specifications used to construct the unit cell model

n_fuel_pins = 211          # number of fuel compacts per assembly
																
num_layers_for_plots = 20                # number of layers to average fields over for plotting
num_layers_for_THM = 20
num_layers = 20 

#density_blocks = 'coolant'
#temperature_blocks = 'Fuel Ceramic GAPHE Clad Reflector barrel'
fuel_blocks = 'Fuel'

[Mesh]
  [mesh]
   type = FileMeshGenerator
   file = SNAP_mesh_9_in.e
  []
[]

[Variables]
  [T]
    initial_condition = ${inlet_T}
  []
[]

[Kernels]
  [diffusion]
    type = HeatConduction
    variable = T
  []
  [source]
    type = CoupledForce
    variable = T
    v = power
    block = ${fuel_blocks}
  []

[]

[BCs]
  [pin_outer]
    type = MatchedValueBC
    variable = T
    v = fluid_temp
    boundary = 'fluid_solid_interface'
  []
[]

#[ICs]
#  [power_density]
#    type = ConstantIC
#    variable = power_density
#    value = ${fparse power / ((n_fuel_pins) * ( pi * fuel_diameter * fuel_diameter * unit_cell_height / 4.0 ))}
#    block = ${fuel_blocks}
#  []
#[]

[Functions]
  [k_Be]
    type = ParsedFunction
    expression = '${reflector_k}'
  []
  #[k_SS]
  #  type = ParsedFunction
  #  expression = '${barrel_k}'
  #[]
  [k_Ceramic]
    type = ParsedFunction
    expression = '${ceramic_k}'
  []
  [k_Clad]
    type = ParsedFunction
    expression = '${clad_k}'
  []
  [k_Gap]
    type = ParsedFunction
    expression = '${gap_k}'
  []
  [k_Fuel0]
    type = ParsedFunction
    expression = '${fuel_k}'
  []
  [radius]
    type = ParsedFunction
    expression = 'sqrt(x*x+y*y)'
   []
[]

[Materials]
  #[Reflector_BeO]
  #  type = HeatConductionMaterial
  #  thermal_conductivity = 216.0
  #  specific_heat = 1925.0
  #  temp = T
  #  block = 'inner_reflector inner_reflector_trim outer_reflector outer_reflector_trim'
  #[]
  [Fuel]
    type = HeatConductionMaterial
    thermal_conductivity = 38.31
    specific_heat = 763.3
    temp = T
    block = 'Fuel'
  []
  [Ceramic]
    type = HeatConductionMaterial
    thermal_conductivity = 1.7307
    specific_heat = 837.36
    temp = T
    block = 'Ceramic'
  []
  [Clad]
    type = HeatConductionMaterial
    thermal_conductivity = 20.3
    specific_heat = 565.0
    temp = T
    block = 'Clad'
  []
  [GAPHE]
    type = HeatConductionMaterial
    thermal_conductivity = 0.3271
    specific_heat = 5193.0
    temp = T
    block = 'GAPHE'
  []
  [barrel]
    type = HeatConductionMaterial
    thermal_conductivity = 16.2
    specific_heat = 500.0
    temp = T
    block = 'barrel'
  []
  #[Reflector_Be]
  #  type = HeatConductionMaterial
  #  thermal_conductivity = 131.54
  #  specific_heat = 2721.42
  #  temp = T
  #  block = 'outer_coolant'
  #[]
[]


[AuxVariables]
  [fluid_temp]
  initial_condition = '${inlet_T}'
  []
  [flux]
    family = MONOMIAL
    order = CONSTANT
  []
  [power]
    family = MONOMIAL
    order = CONSTANT
    #block = ${fuel_blocks}
  []
[]

[AuxKernels]
  [flux]
    type = DiffusionFluxAux
    diffusion_variable = T
    component = normal
    diffusivity = thermal_conductivity
    variable = flux
    boundary = 'fluid_solid_interface'
  []
[]

[UserObjects]
  [average_fuel_axial]
    type = LayeredAverage
    variable = T
    direction = z
    num_layers = ${num_layers_for_plots}
    block = ${fuel_blocks}
  []
  [average_block_axial]
    type = LayeredAverage
    variable = T
    direction = z
    num_layers = ${num_layers_for_plots}
    block = 'Clad'
  []
  #[average_ref_axial]
  #  type = LayeredAverage
  #  variable = T
  #  direction = z
  #  num_layers = ${num_layers_for_plots}
  #  block = 'inner_reflector inner_reflector_trim outer_reflector outer_reflector_trim'
  #[]
  [q_wall_avg]
    type = LayeredSideAverage
    boundary = fluid_solid_interface
    variable = flux

    # Note: make this to match the num_elems in the channel
    direction = z
    num_layers = ${num_layers_for_THM}

    direction_min = 0.0
    direction_max = ${unit_cell_height}
  []
[]

[Outputs]
  exodus = true
  print_linear_residuals = false

  [csv]
    type = CSV
    file_base = 'csv_SNAP/SNAP_solid'
  []
[]

[Executioner]
  #type = Steady
  type = Transient
  nl_abs_tol = 5e-7
  nl_rel_tol = 1e-7
  petsc_options_value = 'hypre boomeramg'
  petsc_options_iname = '-pc_type -pc_hypre_type'

  dt = 0.1
  nl_max_its = 200
  steady_state_detection = true
  steady_state_tolerance = 1e-5
  [./Quadrature]
    type = TRAP
    order = FIRST
  [../]
[]

[Postprocessors]
  [flux_integral] 
    type = SideDiffusiveFluxIntegral
    diffusivity = thermal_conductivity
    variable = T
    boundary = 'fluid_solid_interface'
  []
  [max_fuel_T]
    type = ElementExtremeValue
    variable = T
    value_type = max
    block = ${fuel_blocks}
  []
  [max_block_T]
    type = ElementExtremeValue
    variable = T
    value_type = max
    block = 'Clad'
  []
  #[max_ref_T]
  #  type = ElementExtremeValue
  #  variable = T
  #  value_type = max
  #  block = 'inner_reflector inner_reflector_trim outer_reflector outer_reflector_trim'
  #[]
  [max_barrel_T]
    type = ElementExtremeValue
    variable = T
    value_type = max
    block = 'barrel'
  []
  [power] # evaluate the total power for normalization
    type = ElementIntegralVariablePostprocessor
    variable = power
    block = ${fuel_blocks}
    execute_on = 'transfer'
  []
[]

[VectorPostprocessors]
  [fuel_axial_avg]
    type = SpatialUserObjectVectorPostprocessor
    userobject = average_fuel_axial
  []
  [block_axial_avg]
    type = SpatialUserObjectVectorPostprocessor
    userobject = average_block_axial
  []
  #[ref_axial_avg]
  #  type = SpatialUserObjectVectorPostprocessor
  #  userobject = average_ref_axial
  #[]
  [qwall_avg]
    type = SpatialUserObjectVectorPostprocessor
    userobject = q_wall_avg
  []
[]

[MultiApps]
  [thm]
    #type = FullSolveMultiApp
    type = TransientMultiApp
    app_type = ThermalHydraulicsApp
    input_files = core_2D_Amer.i
    execute_on = timestep_end
    max_procs_per_app = 1
    bounding_box_padding = '0.1 0.1 0'
  []
[]

[Transfers]
  [q_wall_to_thm]
    type = MultiAppGeneralFieldUserObjectTransfer
    variable = q_wall
    to_multi_app = thm
    source_user_object = q_wall_avg 
  []
  [T_wall_from_thm]
    type = MultiAppGeneralFieldNearestLocationTransfer
    source_variable = T_wall
    from_multi_app = thm
    variable = fluid_temp
  []
[]

core_2D_Amer.i:

# ==============================================================================
# Model description
# ------------------------------------------------------------------------------
# Idaho Falls, INL, 2022-07-20 10:50:17
# Author(s): Isaac Naupa Aguirre
# Supervisor: Stefano Terlizzi
# ==============================================================================
# SNAP8ER 2D Core  Wet Operational Conditions, Coupled with Bison.
# For use of this model please cite:
# @InProceedings{s8er_naupa2022,
#     author = "Naupa, Isaac and Garcia, Samuel and Terlizzi, Stefano and Kotlyar, Dan and Lindley, Ben",
#     title = "{(In Preperation) Validation of SNAP8 Criticality Configuration Experiments using NEAMS Tools}",
#     booktitle = "{Proceedings of ANS M\&C}",
#     year = "2022"
# }
# @InProceedings{s8er_garcia2022,
#     author = "Garcia, Samuel and Naupa, Isaac and Kotlyar, Dan and Lindley, Ben",
#     title = "{Validation of SNAP8 Criticality Configuration Experiments using SERPENT}",
#     booktitle = "{Proceedings of ANS Winter Conference}",
#     year = "2022"
# }
# # ==============================================================================
# MODEL PARAMETERS
# ==============================================================================

# Calculations for material property equations and system parameters & dimensions
# can be found under Models/SNAP8ER_dimensions_params_etc.xlsx

# Geometry ---------------------------------------------------------------------
# Reference:
# @techreport{SNAP8Summary,
#     author = "Division, Atomics Internation",
#     title = "{SNAP 8 summary report}",
#     institution = "Atomics Internation Division",
#     year = "1973",
#     doi = "10.2172/4393793",
#     url = "https://www.osti.gov/biblio/4393793"
# }
# fuel_radius               = '${units 0.0067564 m -> cm}'# (m)
# #ceramic_radius_outer      = 0.006826079 # (m)
# #gap_radius_outer          = 0.006866719 # (m)
# clad_radius_outer         = '${units 0.007130879 m -> cm}' # (m)
# fuel_len                  = 35.56 # (m).
# fuel_len_half             = '${fparse fuel_len*0.5}'
#hex_apothem               = 0.007239
##fuel_volume               = ${fparse pi*fuel_len*fuel_radius*fuel_radius} # (m3)
##clad_thickness            = 0.00026416 # (m)
#
#active_apothem            = .110414
#nonactive_corner 		  = .2550
#nonactive_corner_half     = ${fparse nonactive_corner*0.5}
#cut_apothem               = 0.115924
#cut_y                     = 0.057962
#cut_x                     = 0.100393129
#
#scube_apothem             = .11815
#scube_x                   = 0.059075
#scube_y                   = 0.102320901

# System Properties ------------------------------------------------------------
# Reference:
# @techreport{SNAP8Summary,
#     author = "Division, Atomics Internation",
#     title = "{SNAP 8 summary report}",
#      institution = "Atomics Internation Division",
#      year = "1973",
#      doi = "10.2172/4393793",
#      url = "https://www.osti.gov/biblio/4393793"
#  }


# Material Properties ------------------------------------------------------------
# Reference:
# @article{SNAPFuel,
#     author = "Nelson, S G",
#     title = "High-temperature thermal propeties of SNAP-10A fuel material",
#     doi = "10.2172/4260713",
#     url = "https://www.osti.gov/biblio/4260713",
#     journal = "",
#     place = "United States",
#     year = "1965",
#     month = "2"
# }
# clad_density              = 8617.9333 # (kg/m^3)
# clad_tc                   = 18.85239 # (W/m K)
# clad_cp                   = 418.68 # (J/kg-K)
# fuel_density              = 5963 # (kg/m^3)
# gap_tc                    = .346146933
# #gap_dens        = 0.016646998
# #gap_cp          = 5193.163779


# # fuel_dens                    = -0.222222222*T + 6003 
# # fuel_cp                      = -0.222222222*T + 27.73992
# # fuel_tc                      = -0.222222222*T + 472.27104
# ceramic_emiss             = .80
# clad_emiss                = .80

# ceramic_dens              = 2242.584872
# ceramic_cp                = 837.36
# ceramic_tc                = 1.730734666
        
# intref_dens               = 1810.086361
# intref_cp                 = 2721.42
# intref_tc                 = 131.5358346

# barrel_dens               = 7954.00
# barrel_cp                 = 500
# barrel_tc                 = 16.2

# extref_dens               = 1840.00
# extref_cp                 = 1850
# extref_tc                 = 151.000
        
#coolant_dens                  = 800
#coolant_cp                    = 880
#coolant_tc                    = 30


inlet_T_fluid             = 639  # (K) 
ht_coeff                  = 4539.6
fuel_blocks = 'Fuel'
ceram_blocks = 'Ceramic'
clad_blocks = 'Clad'
intref_blocks = 'Reflector'
#barrel_blocks = 'barrel'
extref_blocks = 'Reflector'

#gap_inner = 1
#gap_outer = 2
#clad_outer = 3
#core_inner = 4
#core_outer = 5


#setting initial conditions
# power = 6e+5
# n_fuel_pins = 211
# fuel_diameter = '${fparse 0.67564 * 2 * 0.01}'
# unit_cell_height = '${units 35.56 cm -> m}'
#pow_dens = 55760474.8606

# acm_dz = '${fparse 3.81/100}'
# lay1 = '${fparse 2.1717/100}'
# lay2 = '${fparse 2.9083/100}'
#multi_app_z_pos = 0.03556 #0.0176022
# ==============================================================================
# GEOMETRY AND MESH
# ==============================================================================
[Mesh]
    [core_unextruded]
        type = FileMeshGenerator
        file = SNAP_mesh_9_in.e
    []
    # [transform_core_unextruded]
    #     type = TransformGenerator
    #     input = core_unextruded
    #     transform = SCALE
    #     vector_value = '0.01 0.01 0.01'
    # []
    # [extruded]
    #     type = AdvancedExtruderGenerator
    #     input = transform_core_unextruded
    #     heights = '${lay1} ${acm_dz} ${acm_dz} ${acm_dz} ${acm_dz} ${acm_dz} ${acm_dz} ${acm_dz} ${acm_dz}  ${lay2}'
    #     num_layers = '1 2 3 4 5 6 7 8 9 10'
    #     direction = '0 0 1'    
    # []
[]

# ==============================================================================
# VARIABLES AND KERNELS
# ==============================================================================

# ==============================================================================
# VARIABLES AND KERNELS
# ==============================================================================
[Variables]
    [temp]
        initial_condition = '${inlet_T_fluid}'
    []
[]

[Kernels]
    # Equation 0 (Heat conduction equation with heat generation).
    [heat_conduction]
        type = ADHeatConduction
        variable = temp
    []
    [heat_source]
        type = ADCoupledForce
        variable = temp
        v = norm_power_density
        block = 'Fuel'
        #coef = .93
    []
    # [heat_source_extref]
    #     type = CoupledForce
    #     variable = temp
    #     v = norm_power_density
    #     block = 'Reflector'
    #     coef = .07
    # []
[]

# ==============================================================================
# AUXVARIABLES AND AUXKERNELS
# ==============================================================================
[AuxVariables]
    [power_density]
        family = L2_LAGRANGE 
        order = FIRST 
        block = 'Fuel'
        #initial_condition = '${pow_dens}' #
    []
    [T_inf]
        initial_condition = '${inlet_T_fluid}'
    []
    [Tfuel]
        block = ${fuel_blocks}
    []

    [Tref]
        block = ${extref_blocks}
    []
    [norm_power_density]
        family = L2_LAGRANGE
        order = FIRST
        block = 'Fuel'
        #initial_condition = 2.01E+03
    []
    [HTC]
        family = MONOMIAL
        order = CONSTANT
        initial_condition = '${ht_coeff}'
    []
    [pow_lin]
        family = L2_LAGRANGE
        order = FIRST
        block = 'Fuel'
    []
    [pow_lin_node]
        family = LAGRANGE
        order = FIRST
        block = 'Fuel'
    []
[]

[AuxKernels]
    [norm_Tfuel]
        type = NormalizationAux
        variable = Tfuel
        source_variable = temp
        normal_factor = 1
        execute_on = 'timestep_end' #check
    []
    [norm_Tref]
        type = NormalizationAux
        variable = Tref
        source_variable = temp
        normal_factor = 1
        execute_on = 'timestep_begin' #check
    []
    [aux_power]
        type = FunctionAux
        function = axial_heat_rate
        variable = power_density
        block = 'Fuel'
        execute_on = 'timestep_begin'
    []
    [norm_power_density]
        type = NormalizationAux
        variable = norm_power_density
        source_variable = power_density
        normal_factor = 1#1.2658064684
        execute_on = 'timestep_begin' #check
    []  
    [make_powdens_linear]
        type = NormalizationAux
        variable = pow_lin
        source_variable = power_density
        normal_factor = 0.000143410377564#1.2658064684
        execute_on = 'timestep_end' #check
    []    
    # [pow_lins_to_node]
    #     type = ProjectionAux
    #     v = pow_lin
    #     variable = pow_lin_node
    #     execute_on = 'timestep_end'
    # []
[]

# ==============================================================================
# MULTIAPPS AND TRANSFERS
# ==============================================================================
[MultiApps]
    [sc]
      type = FullSolveMultiApp
    #   app_type = SubChannelApp
      input_files = 'sc_core.i'
      execute_on =  timestep_end
      bounding_box_padding = '0.1 0.1 0'
      positions = '0 0 0'
      output_in_position = true
    #  library_name = 'libcardinal-opt.la'
    #  library_path = '~/cardinal/lib/libcardinal-opt.la'
    []
[]
  
  [Transfers]
    [flux_to_SC]
        type = MultiAppGeneralFieldNearestLocationTransfer
        to_multi_app = sc
        source_variable = pow_lin
        # source_variable = pow_lin
        # variable = q_dens
        # variable = q_prime_element
        variable = q_prime
        from_blocks = 'Fuel'
        to_blocks = fuel_pins
        greedy_search = true
    []
    [coolant_temp_from_SC]
    type = MultiAppGeneralFieldNearestLocationTransfer
    from_multi_app = sc
    source_variable = T
    variable = T_inf
    []
  []

# ==============================================================================
# INITIAL CONDITIONS AND FUNCTIONS
# ==============================================================================
[Functions]
    # [tk_f]
    #     type = ParsedFunction
    #     symbol_names = 'temp'
    #     symbol_values = 'temp_av'
    #     expression = '27.73992+temp*0.027428444'#Models/SNAP10A_dimensions
    # []
    # [cp_f]
    #     type = ParsedFunction
    #     symbol_names = 'temp'
    #     symbol_values = 'temp_av'
    #     expression = '472.27104+temp*0.7275728'#Models/SNAP10A_dimensions
    # []
    [axial_heat_rate]
        type = ParsedFunction
        expression = '55760474.8606'#"if(z > l1 & z < l2, 55760474.8606, 0)"
        symbol_names = 'l1 l2'
        symbol_values = '0 35.56'
    []
[]

# ==============================================================================
# FLUID PROPERTIES, MATERIALS, AND USER OBJECTS
# ==============================================================================

[Materials]
    [Reflector]
      type = ADHeatConductionMaterial
      thermal_conductivity = 216.0
      specific_heat = 1925.0
      temp = temp
      block = 'Reflector'
    []
    [Fuel]
      type = ADHeatConductionMaterial
      thermal_conductivity = 38.31
      specific_heat = 763.3
      temp = temp
      block = 'Fuel'
    []
    [Ceramic]
      type = ADHeatConductionMaterial
      thermal_conductivity = 1.7307
      specific_heat = 837.36
      temp = temp
      block = 'Ceramic'
    []
    [Clad]
      type = ADHeatConductionMaterial
      thermal_conductivity = 20.3
      specific_heat = 565.0
      temp = temp
      block = 'Clad'
    []
    [GAPHE]
      type = ADHeatConductionMaterial
      thermal_conductivity = 0.3271
      specific_heat = 5193.0
      temp = temp
      block = 'GAPHE'
    []
#    [barrel]
#      type = ADHeatConductionMaterial
#      thermal_conductivity = 15.0
#      specific_heat = 460.0
#      temp = temp
#      block = 'out_ref'
#    []
  []

# ==============================================================================
# BOUNDARY CONDITIONS
# ==============================================================================
[BCs]
    # Convective BC outer surface fuel pin
    [convective_boundary]
        type = CoupledConvectiveHeatFluxBC
        variable = temp
        boundary = 'fluid_solid_interface'
        T_infinity = T_inf
        htc = HTC
    []
    # Convective BC outer surface fuel pin
[]

# [ThermalContact]
#     # Gap Heat Transfer 
#     [gap_ht]
#         type = GapHeatTransfer
#         variable = temp
#         gap_geometry_type = 'PLATE'
#         primary = '${gap_inner}'
#         secondary = '${gap_outer}'
#         emissivity_primary = '${ceramic_emiss}'
#         emissivity_secondary = '${clad_emiss}'
#         gap_conductivity = '${gap_tc}' # W/mK
#         quadrature = true
#     []
#    [gap_ht_ref]
#        type = GapHeatTransfer
#        variable = temp
#        gap_geometry_type = 'PLATE'
#        primary = '${clad_outer}'
#        secondary = '${core_inner}'
#        emissivity_primary = '${ceramic_emiss}'
#        emissivity_secondary = '${clad_emiss}'
#        gap_conductivity = '${gap_tc}' # W/mK
#        quadrature = true
#    []
# []

# ==============================================================================
# EXECUTION PARAMETERS
# ==============================================================================
[Executioner]
    type = Steady
    nl_rel_tol = 1e-8
    nl_abs_tol = 1e-8
    nl_abs_step_tol = 1e-8
    l_tol = 1e-8
    solve_type = NEWTON
#   petsc_options_value = 'hypre boomeramg'
#   petsc_options_iname = '-pc_type -pc_hypre_type'
  petsc_options_value = 'bjacobi'
  petsc_options_iname = '-pc_type'
#   fixed_point_max_its = 10
  #force_fixed_point_solve = true
[]

# ==============================================================================
# POSTPROCESSORS DEBUG AND OUTPUTS
# ==============================================================================
[Postprocessors]
    [temp_max]
        type = ElementExtremeValue
        variable = temp
        value_type = max
        block = '${fuel_blocks}'
    []
    [temp_min]
        type = ElementExtremeValue
        variable = temp
        value_type = min
        block ='${fuel_blocks}'
    []
    [power]
        type = ElementIntegralVariablePostprocessor
        variable = power_density
        #use_displaced_mesh = true # check
        block = ${fuel_blocks}
        execute_on = 'initial timestep_end'
    []
    [norm_power]
        type = ElementIntegralVariablePostprocessor
        variable = norm_power_density
        #use_displaced_mesh = true # check
        block = ${fuel_blocks}
        execute_on = 'initial timestep_end'
    []
    [power_density_avg]
        type = ElementAverageValue
        variable = power_density
        #use_displaced_mesh = true # check
        block = ${fuel_blocks}
        execute_on = 'initial timestep_end'
    []
    [norm_power_density_avg]
        type = ElementAverageValue
        variable = norm_power_density
        #use_displaced_mesh = true # check
        block = ${fuel_blocks}
        execute_on = 'initial timestep_end'
    []
    [fuel_vol]
        type = VolumePostprocessor
        block = ${fuel_blocks}
    []
    [intref_vol]
        type = VolumePostprocessor
        block = ${intref_blocks}
    []
    [clad_vol]
        type = VolumePostprocessor
        block = ${clad_blocks}
    []
    [ceramic_vol]
        type = VolumePostprocessor
        block = ${ceram_blocks}
    []
[]

[VectorPostprocessors]
    [pow_dens]
        type = LineValueSampler
        start_point = '0 0 0.05'
        end_point = '0 0 0.355'
        num_points = 10
        variable = pow_lin
        sort_by = 'z'
    []
[]

[Outputs]
    [csv]
        type = CSV
        execute_on = 'initial timestep_end'
    []
    # [nemesis]
    #     type = Nemesis
    # []
[]

sc_core.i:

# Following Advanced Burner Test Reactor Preconceptual Design Report
# Vailable at: https://www.ne.anl.gov/eda/ABTR_1cv2_ws.pdf
###################################################
# Thermal-hydraulics parameters
###################################################
T_in = 866.0 
P_out = 253727.1   # Pa
# reactor_power = 671337.24 #WTh
#fuel_assemblies_per_power_unit = '${fparse 1}'
#fuel_pins_per_assembly = 211
#pin_power = '${fparse reactor_power/(fuel_assemblies_per_power_unit*fuel_pins_per_assembly)}' # Approx.
mass_flow = '${fparse 6.15}' # kg/(s)

###################################################
# Geometric parameters
###################################################
#f = '${fparse sqrt(3) / 2}'

# units are cm - do not forget to convert to meter
scale_factor = 0.01
#duct_thickness = '${fparse 0.3*scale_factor}'
fuel_pin_pitch = '${fparse 1.4478*scale_factor}'
fuel_pin_diameter = '${fparse 1.4268*scale_factor}'
wire_z_spacing = '${fparse 0*scale_factor}'
wire_diameter = '${fparse 0*scale_factor}'
n_rings = 9
#length_entry_fuel = '${fparse 0*scale_factor}'
length_heated_fuel = '${fparse 35.56*scale_factor}'
#length_outlet_fuel = '${fparse 0*scale_factor}'
#height = '${fparse length_entry_fuel+length_heated_fuel+length_outlet_fuel}'
#orifice_plate_height = '${fparse 0*scale_factor}'
duct_inside = '${fparse 11.43*2*scale_factor}'

# entry1 = '${fparse 0.79502/100}'
# entry2 = '${fparse 0.9652/100}'
# entry3 = '${fparse 2.1717/100}'
entry1 = '${fparse 0/100}'
entry2 = '${fparse 0/100}'
entry3 = '${fparse 0/100}'
entry_length = '${fparse entry1 + entry2 + entry3}'
# exit1 = '${fparse 2.9083/100}'
# exit2 = '${fparse 0.2286/100}'
# exit3 = '${fparse 0.87376/100}'
exit1 = '${fparse 0/100}'
exit2 = '${fparse 0/100}'
exit3 = '${fparse 0/100}'
exit_length = '${fparse exit1 + exit2 + exit3}'#'${fparse exit2 + exit3}'#
###################################################

[TriSubChannelMesh]
  [subchannel]
    type = SCMTriSubChannelMeshGenerator
    nrings = '${fparse n_rings}'
    n_cells = 10
    flat_to_flat = '${fparse duct_inside}'
    unheated_length_entry = '${fparse entry_length}'
    heated_length = '${fparse length_heated_fuel}'
    unheated_length_exit = '${fparse exit_length}'
    pin_diameter = '${fparse fuel_pin_diameter}'
    pitch = '${fparse fuel_pin_pitch}'
    dwire = '${fparse wire_diameter}'
    hwire = '${fparse wire_z_spacing}'
    spacer_z = '0'
    spacer_k = '0'
  []

  [fuel_pins]
    type = SCMTriPinMeshGenerator
    input = subchannel
    nrings = '${fparse n_rings}'
    n_cells = 10
    unheated_length_entry = '${fparse entry_length}'
    heated_length = '${fparse length_heated_fuel}'
    unheated_length_exit = '${fparse exit_length}'
    pitch = '${fparse fuel_pin_pitch}'
  []

  [duct]
    type = SCMTriDuctMeshGenerator
    input = fuel_pins
    nrings = '${fparse n_rings}'
    n_cells = 10
    flat_to_flat = '${fparse duct_inside}'
    unheated_length_entry = '${fparse entry_length}'
    heated_length = '${fparse length_heated_fuel}'
    unheated_length_exit = '${fparse exit_length}'
    pitch = '${fparse fuel_pin_pitch}'
  []
[]


# [Functions]
#   [axial_heat_rate]
#     type = ParsedFunction
#     expression = '1.0'
#     symbol_names = 'l1 l2'
#     symbol_values = '${entry_length} ${fparse length_heated_fuel}'
#   []
# []

[AuxVariables]
  [mdot]
    block = subchannel
  []
  [SumWij]
    block = subchannel
  []
  [P]
    block = subchannel
  []
  [DP]
    block = subchannel
  []
  [h]
    block = subchannel
  []
  [T]
    block = subchannel
  []
  [Tpin]
    block = fuel_pins
  []
  [Dpin]
    block = fuel_pins
  []
  [rho]
    block = subchannel
  []
  [S]
    block = subchannel
  []
  [w_perim]
    block = subchannel
  []
  [q_prime]
    block = fuel_pins
    #initial_condition = 7000
  []
  [mu]
    block = subchannel
  []
  [q_prime_duct]
    block = duct
    initial_condition = 0
  []
  [Tduct]
    block = duct
  []
  [displacement]
    block = subchannel
    initial_condition = 0
  []
[]

[FluidProperties]
  [sodium]
    type = SimpleFluidProperties
    molar_mass = 0.0355
    cp = 873.0
    cv = 873.0
    specific_entropy = 1055
    viscosity = 0.0001582
    thermal_conductivity = 25.9
    thermal_expansion = 2.77e-4
  []
[]

[Problem]
  type = TriSubChannel1PhaseProblem
  fp = sodium
  n_blocks = 1
  P_out = ${P_out}
  CT = 1.0
  compute_density = false #true
  compute_viscosity = true #true
  compute_power = true #true
  P_tol = 1.0e-2
  T_tol = 1.0e-2
  implicit = true
  segregated = false
  staggered_pressure = false
  monolithic_thermal = true
  # verbose_multiapps = true
  # verbose_subchannel = true
  # type = NoSolveProblem
[]


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

  [w_perim_IC]
    type = SCMTriWettedPerimIC
    variable = w_perim
  []
  
  # [q_prime_IC]
  #   type = SCMTriPowerIC
  #   variable = q_prime
  #   power = ${reactor_power} # W
  #   filename = "/home/garcsamu/Serpent/SNAP-REACTORS-PRIVATE/snapReactors/reactor_models/Wet_Experiment_Models/standard_conditions/sc_test/sc_standalone/S8ER_pin.txt"
  #   axial_heat_rate = axial_heat_rate
  # []

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

  [Dpin_ic]
    type = ConstantIC
    variable = Dpin
    value = ${fuel_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 = sodium
  []

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

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

  [T_duct_ic]
    type = ConstantIC
    variable = Tduct
    value = ${T_in}
  []
  [mdot_ic]
    type = ConstantIC
    variable = mdot
    value = 0.0
  []
[]

[AuxKernels]
  [T_in_bc]
    type = ConstantAux
    variable = T
    boundary = inlet
    value = ${T_in}
    execute_on = 'initial timestep_begin'
    block = subchannel
  []
  [mdot_in_bc]
    type = SCMFlatMassFlowRateAux
    variable = mdot
    boundary = inlet
    #area = S
    mass_flow = ${mass_flow}
    execute_on = 'initial timestep_begin'
    block = subchannel
  []
[]

[UserObjects]
  active = ''
  [Tpin_avg_uo]
    type = NearestPointLayeredAverage
    direction = z
    num_layers = 10
    variable = Tpin
    block = fuel_pins
    points = '${fparse 0.012} 0.0 0.0'
    execute_on = timestep_end
  []
[]

[VectorPostprocessors]
  [pow_dens]
      type = LineValueSampler
      start_point = '0 0 0.05'
      end_point = '0 0 0.355'
      num_points = 10
      variable = q_prime
      sort_by = 'z'
      execute_on = 'initial timestep_begin'
  []
[]
[Outputs]
  [exodus]
    type = Exodus
    execute_on = 'timestep_end'
[]
[csv]
    type = CSV
    execute_on = 'initial timestep_end'
[]
[]

[Executioner]
  type = Steady
  petsc_options_value = 'hypre boomeramg'
  petsc_options_iname = '-pc_type -pc_hypre_type'
  # steady_state_detection = true
  # steady_state_tolerance = 1e-4

[]

################################################################################
# A multiapp that projects data to a detailed mesh
################################################################################
[MultiApps]
  #active = ''
  [viz]
    type = FullSolveMultiApp
    input_files = "sc_core_viz.i"
    execute_on = "final"
  []
[]

[Transfers]
  #active = ''
  [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'
  []
[]

sc_core_viz.i:

# Following Advanced Burner Test Reactor Preconceptual Design Report
# Vailable at: https://www.ne.anl.gov/eda/ABTR_1cv2_ws.pdf
###################################################
# Thermal-hydraulics parameters
###################################################
#T_in = 866.0 
#P_out = 253727.1   # Pa
#reactor_power = 600000 #WTh
#fuel_assemblies_per_power_unit = '${fparse 1}'
#fuel_pins_per_assembly = 211
#pin_power = '${fparse reactor_power/(fuel_assemblies_per_power_unit*fuel_pins_per_assembly)}' # Approx.
#mass_flow = '${fparse 6.15}' # kg/(s)

###################################################
# Geometric parameters
###################################################
#f = '${fparse sqrt(3) / 2}'

# units are cm - do not forget to convert to meter
scale_factor = 0.01
#duct_thickness = '${fparse 0.3*scale_factor}'
fuel_pin_pitch = '${fparse 1.4478*scale_factor}'
fuel_pin_diameter = '${fparse 1.42748*scale_factor}'
n_rings = 9
#length_entry_fuel = '${fparse 0*scale_factor}'
length_heated_fuel = '${fparse 35.56*scale_factor}'
#length_outlet_fuel = '${fparse 0*scale_factor}'
#height = '${fparse length_entry_fuel+length_heated_fuel+length_outlet_fuel}'
#orifice_plate_height = '${fparse 0*scale_factor}'
duct_inside = '${fparse 11.43*2*scale_factor}'

# entry1 = '${fparse 0.79502/100}'
# entry2 = '${fparse 0.9652/100}'
# entry3 = '${fparse 2.1717/100}'
entry1 = '${fparse 0/100}'
entry2 = '${fparse 0/100}'
entry3 = '${fparse 0/100}'
entry_length = '${fparse entry1 + entry2 + entry3}'
# exit1 = '${fparse 2.9083/100}'
# exit2 = '${fparse 0.2286/100}'
# exit3 = '${fparse 0.87376/100}'
exit1 = '${fparse 0/100}'
exit2 = '${fparse 0/100}'
exit3 = '${fparse 0/100}'
exit_length = '${fparse exit1 + exit2 + exit3}'#'${fparse exit2 + exit3}'#
###################################################

[TriSubChannelMesh]
  [subchannel]
    type = SCMDetailedTriSubChannelMeshGenerator
    nrings = '${fparse n_rings}'
    n_cells = 10
    flat_to_flat = '${fparse duct_inside}'
    unheated_length_entry = '${fparse entry_length}'
    heated_length = '${fparse length_heated_fuel}'
    unheated_length_exit = '${fparse exit_length}'
    pin_diameter = '${fparse fuel_pin_diameter}'
    pitch = '${fparse fuel_pin_pitch}'
  []

  [fuel_pins]
    type = SCMDetailedTriPinMeshGenerator
    input = subchannel
    nrings = '${fparse n_rings}'
    n_cells = 10
    unheated_length_entry = '${fparse entry_length}'
    heated_length = '${fparse length_heated_fuel}'
    unheated_length_exit = '${fparse exit_length}'
    pitch = '${fparse fuel_pin_pitch}'
    pin_diameter = '${fparse fuel_pin_diameter}'
  []

[]


[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
  []
[]

[Problem]
  type = NoSolveProblem
[]

[Outputs]
  exodus = true
[]

[Executioner]
  type = Steady
  petsc_options_value = 'hypre boomeramg'
  petsc_options_iname = '-pc_type -pc_hypre_type'
  # steady_state_detection = true
  # steady_state_tolerance = 1e-4
[]

Answered by GiudGiud

Jul 22, 2025

ok it s still not very clear. Can you edit the post and add the file names>?

Is the subchannel simulation created by a descendent of this app?

[MultiApps]
  [thm]
    #type = FullSolveMultiApp
    type = TransientMultiApp
    app_type = ThermalHydraulicsApp
    input_files = core_2D_Amer.i
    execute_on = timestep_end
    max_procs_per_app = 1
    bounding_box_padding = '0.1 0.1 0'
  []
[]

because this app is a THMApp which cannot use SCM

View full answer

GiudGiud · 2025-07-22T21:19:17Z

GiudGiud
Jul 22, 2025
Collaborator

hello

what is the name of the .i file / the MultiApps block that creates this subchannel simulation?

I see some use of app_type in your MultiApps block. If it's the wrong app that could be the problem

6 replies

willschlueter Jul 22, 2025
Author

I believe it is the SNAP_master.i file that does that, which uses app_type=CardinalApp

GiudGiud Jul 22, 2025
Collaborator

I dont see SNAP_master.i in your MultiApps blocks

willschlueter Jul 22, 2025
Author

Sorry, the first file linked is called SNAP_master.i and has the multiApps block with app_type=CardinalApp. It takes SNAP_solid_8.i (the second file) as an input. SNAP_solid_8.i then takes the first subchannel file as an input which then takes the second subchannel file as an input, which is where the Problem block is

GiudGiud Jul 22, 2025
Collaborator

ok it s still not very clear. Can you edit the post and add the file names>?

Is the subchannel simulation created by a descendent of this app?

[MultiApps]
  [thm]
    #type = FullSolveMultiApp
    type = TransientMultiApp
    app_type = ThermalHydraulicsApp
    input_files = core_2D_Amer.i
    execute_on = timestep_end
    max_procs_per_app = 1
    bounding_box_padding = '0.1 0.1 0'
  []
[]

because this app is a THMApp which cannot use SCM

Answer selected by willschlueter

willschlueter Jul 23, 2025
Author

That block was indeed where the problem was. Thanks again for all your help and patience!

kyriv1980 Jul 28, 2025

the combined-opt executable can run both THM and SCM files.

Provide feedback

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Subchannel coupling with openmc not recognizing TriSubChannel1PhaseProblem #31102

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Subchannel coupling with openmc not recognizing TriSubChannel1PhaseProblem #31102

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willschlueter Jul 22, 2025

Replies: 1 comment · 6 replies

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GiudGiud Jul 22, 2025 Collaborator

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Jul 22, 2025

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GiudGiud
Jul 22, 2025
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GiudGiud Jul 22, 2025
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