Radiation

Warning

• MFIX-Exa must be built with RTE enabled which requires hypre.

The following inputs are defined using the prefix radiation:

Key	Description	Type	Default
model	Radiation model. Options: P1 - \(\mathrm{P}_1\) spherical-harmonics approximation. FV - Finite-volume discretization of the radiation transport equation.	String	None
enable_scaling	Enable mean beam-length scaling.	Bool	false
update_int	Solve for the radiation intensity on the interval in time steps. This input cannot be specified with radiation.update_per_approx.	Int	None
update_per_approx	Solve for the radiation intensity on the approximted lapsed time. This input cannot be specified with radiation.update_int.	Int	None

RTE P₁ solver

The following inputs are defined using the prefix rte.P1:

Key	Description	Type	Default
A1	Legendre coefficient for scattering phase function.	Real
maxConvergeIter	Maximum allowed iterations to get a converged solution.	Int	10
L2_convergence_tol	Convergence threshold on L2 norm of incident radiation (G).	Real	1.0e-5
NOS_correction	Non-orthogonal and skewness correction on face fluxes.	Bool	false
flux_redistribution	Redistribute the flux or not during the non-orthogonal corrections.	Bool	false
LeastSquare_stencil_size	Stencil size for the least square regression.	Int	3

RTE FV solver

The following inputs are defined using the prefix rte.fv:

Key	Description	Type	Default
quadrature_resolution_theta	Number of polar discretizations in each quadrature.	Int	None
quadrature_resolution_phi	Number of azimuthal discretizations in each quadrature.	Int	None
maxConvergeIter	Maximum allowed iterations to get a converged solution.	Int	10
explicit_correction	Deferred correction	Bool	false

Hypre settings

Warning

• These inputs are all case-sensitive.

hypre settings are specified using the following inputs which are read directly by the RTE library. The following inputs are defined using the prefix rte.hypre:

	Description	Type	Default
preconditioner	Type of preconditioner. Options: BoomerAMG	String	None
solver	Type of hypre solver. Options: GMRES BiCGSTAB BoomerAMG	String	None
verbose	Verbosity of hypre.	Int	0
num_krylov	Number of iterations.	Int	50
convergence_tol	Convergence tolerance.	Real	1.0e-4
max_iterations	Maximum number of iterations.	Int	1000

The following inputs are valid when using BoomerAMG as a preconditioner or solver. They must be defined using the prefix rte.hypre:

	Description	Type	Default
bamg_agg_interp_type	See HYPRE_BoomerAMGSetAggInterpType.	Int	4
bamg_agg_num_levels	See HYPRE_BoomerAMGSetAggNumLevels.	Int	0
bamg_agg_pmax_elmts	See HYPRE_BoomerAMGSetAggPMaxElmts.	Int	0
bamg_coarse_relax_type	See HYPRE_BoomerAMGSetCycleRelaxType.	Int	11
bamg_coarsen_type	See HYPRE_BoomerAMGSetCoarsenType.	Int	6
bamg_cycle_type	See HYPRE_BoomerAMGSetCycleType.	Int	1
bamg_down_relax_type	See HYPRE_BoomerAMGSetCycleRelaxType.	Int	11
bamg_interp_type	See HYPRE_BoomerAMGSetInterpType.	Int	0
bamg_keep_transpose	See HYPRE_BoomerAMGSetKeepTranspose.	Int	0
bamg_logging	See HYPRE_BoomerAMGSetLogging.	Int	0
bamg_max_coarse_size	See HYPRE_BoomerAMGSetMaxCoarseSize.	Int	9
bamg_max_iterations	See HYPRE_BoomerAMGSetMaxIter.	Int	1
bamg_max_levels	See HYPRE_BoomerAMGSetMaxLevels.	Int	20
bamg_min_coarse_size	See HYPRE_BoomerAMGSetMinCoarseSize.	Int	1
bamg_num_coarse_sweeps	See HYPRE_BoomerAMGSetCycleNumSweeps.	Int	1
bamg_num_down_sweeps	See HYPRE_BoomerAMGSetCycleNumSweeps.	Int	2
bamg_num_sweeps	See HYPRE_BoomerAMGSetNumSweeps.	Int	2
bamg_num_up_sweeps	See HYPRE_BoomerAMGSetCycleNumSweeps.	Int	2
bamg_pmax_elmts	See HYPRE_BoomerAMGSetPMaxElmts.	Int	4
bamg_precond_tolerance	See HYPRE_BoomerAMGSetTol.	Real	0.0
bamg_relax_order	See HYPRE_BoomerAMGSetRelaxOrder.	Int	1
bamg_relax_type	See HYPRE_BoomerAMGSetRelaxType.	Int	6
bamg_set_restriction	See HYPRE_BoomerAMGSetRestriction.	Int	0
bamg_strong_threshold	See HYPRE_BoomerAMGSetStrongThreshold.	Real	0.57
bamg_trunc_factor	See HYPRE_BoomerAMGSetTruncFactor.	Real	0.1
bamg_up_relax_type	See HYPRE_BoomerAMGSetCycleRelaxType.	Int	11
bamg_variant	See HYPRE_BoomerAMGSetVariant.	Int	0
bamg_verbose	Set BoomerAMG verbosity.	Int	0

Note

This list is likely incomplete because the AMReX / hypre interface continues to evolve.