Participating Media Radiation (DOM) Model Reference

Use this model in simulations that include media that can absorb, emit, or scatter thermal radiation.

Theory Theory Guide—Participating Media Radiation
Provided By [physics continuum] > Models > Radiation
Example Node Path Continua > Physics 1 > Models > Participating Media Radiation (DOM)
Requires
  • Space: any
  • Optional Models: Radiation
Properties Ordinate Sets. See Participating Media Radiation (DOM) Properties.
Activates Region Inputs See Participating Media Radiation (DOM) Boundary Settings.
Solvers DO Radiation See The DO Radiation Solver.
Field Functions Boundary Irradiation, Boundary Radiation Heat Flux, Boundary Radiosity, Incident Radiation, Radiative Absorption, Radiative Energy Source, Radiative Intensity n, Total Absorption Coefficient, Total Emissivity. See Radiation Field Functions Reference.

The Participating Media Radiation (DOM) model is not compatible with the Multi-Part Solid model.

Participating Media Radiation (DOM) Properties

Ordinate Sets
Sets the order of discrete ordinate method to n. For a given choice Sn, the number of ordinates is n*(n+2), so increasing the size of the discrete ordinate set significantly increases both accuracy and computational time. The default is S4.

Sn quadratures are implemented to provide angular discretization in the Discrete Ordinate Method. See [410]. Sn sets are implemented for n = {2,4,6,8,12,16}. S2 through S8 are based on odd-moment formulation. S12 and S16 are based on even-moment formulation (to avoid negative weights as occur for n > 10 in odd-moment formulation).

Participating Media Radiation (DOM) Boundary Settings

Inflow, Outflow, Free Stream, and Wall Boundaries
Radiation Flux Option
This option allows you to model diffuse radiation sources at boundaries according to your own specification. See Diffuse Radiation Flux.
Radiation Flux OptionCorresponding Physics Value Nodes
No fluxNone
Diffuse radiation flux
Diffuse Radiation Flux
The diffuse radiation flux is specified as a scalar profile. Requires the Multiband Thermal Radiation or Gray Thermal Radiation model.
Inflow, Outflow, and Free Stream
Radiation Temperature
The temperature of an open boundary that has a total radiant emittance identical to that of a black body. See Radiation Temperature.

The DO Radiation Solver

The DO Radiation solver is activated by default, after Participating Media Radiation has been selected in the Physics Model Selection dialog and a case geometry has been imported.

To tune the performance of the solver, you can alter a number of the properties that are displayed in the Properties window after selecting the DO Radiation node.

If you are using overset mesh and the mesh is modified, for instance by mesh motion or by using the Adaptive Mesh Refinement model, the solver updates the DOM solution even if the current step is not at the iteration frequency update point according to the Update Frequency setting. Overset mesh in DOM requires no additional boundary set-up, but does require the same continuum on both sides, since it is a region-based indirect interface.
DO Radiation Solver Properties
Under-Relaxation Factor
Applies under-relaxation to the solution of the ordinate equations. The default value (1.0) means that no under-relaxation is used.
Maximum Iteration
Controls the maximum number of internal iterations that are required to solve the ordinate equations. The default value (50) is adequate in most scenarios.
Solver Tolerance
Defines the accuracy that is required in the iterative solution of the ordinate equations. The default value (1.0E-5) is adequate in most scenarios.
Verbosity
Provides extra output for this value while the simulation is running. This property can be useful for debugging problems when they occur.
none Leaves output at its default.
low Displays the convergence history for the DOM solution.
high (Currently displays the same output as low.)
冻结求解器
开启时，求解器在迭代过程中不更新任何物理量。该选项默认情况下关闭。这是一个调试选项，由于缺少储存，它可能导致不可恢复的错误和错误的求解。有关详细信息，请参见有限体积求解器参考。
Reconstruction Frozen
When On, uses reconstruction gradients from the last iteration in which they were updated. Temporary Storage Retained must also be on. The default is Off.
Reconstruction Zeroed
When On, sets reconstruction gradients to zero at the next iteration. Gradients remain zeroed until you turn it Off again. The default is Off.
Temporary Storage Retained
When On, retains temporary storage at the end of the iteration. Examples include the ap coefficients, the residual, the corrections, the reconstruction gradients, and the cell gradients. These quantities become available as field functions during subsequent iterations. The default is Off.
Sub-Node Parameters
Additional parameters are available in sub-nodes under the DO Radiation solver: