SCMQuadSubChannelMeshGenerator

Creates a mesh of 1D subchannels in a square lattice arrangement

Overview

This mesh generator creates the mesh were the SCM solution variables associated with the subchannels live. The user needs to provide the number of subchannels "nx" in the -x direction and "ny" in the -y direction. The number of cells in the -z direction is given by "n_cells". The distance of the pins from eachother is given by the "pitch" parameter and the total length of the sub-assembly is defined by the parameters: "heated_length","unheated_length_entry","unheated_length_entry". The fuel pin diameter is given by "pin_diameter". The user also has the ability to define the effect of spacers or mixing vanes on the subassembly by defining their axial location "spacer_z" and a local presure from loss "spacer_k". Last the "spacer_k" is an added distance between a perimetric pin and the duct, such that: Edge Pitch W = (pitch/2 - pin_diameter/2 + gap). The center of the mesh is the origin.

Example Input File Syntax

[QuadSubChannelMesh<<<{"href": "../../syntax/QuadSubChannelMesh/index.html"}>>>]
  [sub_channel]
    type = SCMQuadSubChannelMeshGenerator<<<{"description": "Creates a mesh of 1D subchannels in a square lattice arrangement", "href": "SCMQuadSubChannelMeshGenerator.html"}>>>
    nx<<<{"description": "Number of channels in the x direction [-]"}>>> = 6
    ny<<<{"description": "Number of channels in the y direction [-]"}>>> = 6
    n_cells<<<{"description": "The number of cells in the axial direction"}>>> = 10
    pitch<<<{"description": "Pitch [m]"}>>> = 0.0126
    pin_diameter<<<{"description": "Rod diameter [m]"}>>> = ${pin_diameter}
    gap<<<{"description": "(Its an added distance between a perimetric pin and the duct: Edge Pitch W = (pitch/2 - pin_diameter/2 + gap) [m]"}>>> = 0.00095 # the half gap between sub-channel assemblies
    heated_length<<<{"description": "Heated length [m]"}>>> = 1.0
    spacer_z<<<{"description": "Axial location of spacers/vanes/mixing_vanes [m]"}>>> = '0.0'
    spacer_k<<<{"description": "K-loss coefficient of spacers/vanes/mixing_vanes [-]"}>>> = '0.0'
  []

  [fuel_pins]
    type = SCMQuadPinMeshGenerator<<<{"description": "Creates a mesh of 1D fuel pins in a square lattice arrangement", "href": "SCMQuadPinMeshGenerator.html"}>>>
    input<<<{"description": "The corresponding subchannel mesh"}>>> = sub_channel
    nx<<<{"description": "Number of subchannels in the x direction [-]"}>>> = 6
    ny<<<{"description": "Number of subchannels in the y direction [-]"}>>> = 6
    n_cells<<<{"description": "The number of cells in the axial direction"}>>> = 10
    pitch<<<{"description": "Pitch [m]"}>>> = 0.0126
    heated_length<<<{"description": "Heated length [m]"}>>> = 1.0
  []
[]

Input Parameters

gap(Its an added distance between a perimetric pin and the duct: Edge Pitch W = (pitch/2 - pin_diameter/2 + gap) [m]
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:(Its an added distance between a perimetric pin and the duct: Edge Pitch W = (pitch/2 - pin_diameter/2 + gap) [m]
heated_lengthHeated length [m]
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Heated length [m]
n_cellsThe number of cells in the axial direction
C++ Type:unsigned int
Controllable:No
Description:The number of cells in the axial direction
nxNumber of channels in the x direction [-]
C++ Type:unsigned int
Controllable:No
Description:Number of channels in the x direction [-]
nyNumber of channels in the y direction [-]
C++ Type:unsigned int
Controllable:No
Description:Number of channels in the y direction [-]
pin_diameterRod diameter [m]
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Rod diameter [m]
pitchPitch [m]
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Pitch [m]

Required Parameters

Kij0.5Lateral form loss coefficient [-]
Default:0.5
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Lateral form loss coefficient [-]
block_id0Domain Index
Default:0
C++ Type:unsigned int
Controllable:No
Description:Domain Index
index_blockage0 index of subchannels affected by blockage
Default:0
C++ Type:std::vector<unsigned int>
Controllable:No
Description:index of subchannels affected by blockage
k_blockage0 Form loss coefficient of subchannels affected by blockage
Default:0
C++ Type:std::vector<double>
Unit:(no unit assumed)
Controllable:No
Description:Form loss coefficient of subchannels affected by blockage
reduction_blockage1 Area reduction of subchannels affected by blockage (number to muliply the area)
Default:1
C++ Type:std::vector<double>
Unit:(no unit assumed)
Controllable:No
Description:Area reduction of subchannels affected by blockage (number to muliply the area)
spacer_kK-loss coefficient of spacers/vanes/mixing_vanes [-]
C++ Type:std::vector<double>
Unit:(no unit assumed)
Controllable:No
Description:K-loss coefficient of spacers/vanes/mixing_vanes [-]
spacer_zAxial location of spacers/vanes/mixing_vanes [m]
C++ Type:std::vector<double>
Unit:(no unit assumed)
Controllable:No
Description:Axial location of spacers/vanes/mixing_vanes [m]
unheated_length_entry0Unheated length at entry [m]
Default:0
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Unheated length at entry [m]
unheated_length_exit0Unheated length at exit [m]
Default:0
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Unheated length at exit [m]
z_blockage0 0 axial location of blockage (inlet, outlet) [m]
Default:0 0
C++ Type:std::vector<double>
Unit:(no unit assumed)
Controllable:No
Description:axial location of blockage (inlet, outlet) [m]

Optional Parameters

enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Controllable:No
Description:Set the enabled status of the MooseObject.
save_with_nameKeep the mesh from this mesh generator in memory with the name specified
C++ Type:std::string
Controllable:No
Description:Keep the mesh from this mesh generator in memory with the name specified

Advanced Parameters

nemesisFalseWhether or not to output the mesh file in the nemesisformat (only if output = true)
Default:False
C++ Type:bool
Controllable:No
Description:Whether or not to output the mesh file in the nemesisformat (only if output = true)
outputFalseWhether or not to output the mesh file after generating the mesh
Default:False
C++ Type:bool
Controllable:No
Description:Whether or not to output the mesh file after generating the mesh
show_infoFalseWhether or not to show mesh info after generating the mesh (bounding box, element types, sidesets, nodesets, subdomains, etc)
Default:False
C++ Type:bool
Controllable:No
Description:Whether or not to show mesh info after generating the mesh (bounding box, element types, sidesets, nodesets, subdomains, etc)

Debugging Parameters

(moose/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
[]

Overview
Example Input File Syntax
Input Parameters