4.4.1.2. SPn Radiation

Beta Capability

is not well tested and should not be considered a production capability.

Below is an example input deck with relevant command blocks for the SPn equations coupled monolithically to the energy equation through a radiative heating source and radiative heat flux. Note several command lines and blocks have been left out to focus on the incremental change needed to add the equations (with relevant boundary conditions and initial conditions) to a model.

# Use aprepro to define the SPn order as it will need to be referenced
# in multiple locations in a consistent fashion.
#{SPN_ORDER=3}

Begin Sierra myJob
  ...

  Begin Global Constants
    Stefan Boltzmann Constant = 5.67e-8
  End

  # define absorbtion, scatter, emissivity models for the block
  Begin Aria Material my_pmr_material
    ...
    absorption cross section = constant abs = 0.5
    scattering cross section = constant scat = 0.1
    emissivity = constant e = 1.0
  End
  ...

  Begin Procedure My_Aria_Procedure
    ...
    Begin Aria Region My_Region
      ...

      # Define steady heat conduction
      EQ energy for temperature on block_1 using Q1 with diff src
      BC dirichlet for temperature on my_dirichlet_surfaces = constant value = 1000

      # Couple to SPn eqns via radiative heat source
      source for energy on block_1 = rte_sp order = {SPN_ORDER}

      # Couple to SPn eqns via radiative flux
      BC flux for energy on my_rad_flux_surfaces = RTE_SP order = {SPN_ORDER}

      # Define SPn radiation equation set of order N resulting in (N + 1) / 2 angular intensity DOFs
      EQ sp {SPN_ORDER} for angular_intensity on block_1 using Q1

      # Apply Mark BCs for the SPn equation(s)
      BC Flux for sp on all_surfaces = mixed

      IC for temperature on block_1 = constant value = 1000.0

      # Define SPn ICs (initial guess to steady problem)
      IC for angular_intensity_0 on block_1 = constant value = 10420.116122115
      IC for angular_intensity_1 on block_1 = constant value = 10420.116122115

      # Define SPn nodal variables for output
      Begin Results Output Label Spn
        ...
        nodal variables = rte_scalar_flux as G
        nodal variables = rte_radiative_flux as q
        nodal variables = SPn_flux_0 as S0
        nodal variables = SPn_flux_1 as S1
        nodal variables = solution->angular_Intensity_0 as I0
        nodal variables = solution->angular_Intensity_1 as I1
      End
    End
  End
End Sierra myJob