RADOPT, --, FLUXTOL, SOLVER, MAXITER, TOLER, OVERRLEX, --, --, --, --, MAXFLUXITER
Specifies Radiosity Solver options.
--Unused field.
-
FLUXTOL Convergence tolerance for radiation flux. Defaults to 0.0001. This value is a relative tolerance.
-
SOLVER Choice of solver for radiosity calculation:
0
—
Gauss-Seidel iterative solver (default).
1
—
Direct solver.
2
—
Jacobi solver.
-
MAXITER Maximum number of iterations for iterative solver (
SOLVER= 0 or 2). Defaults to 1000.-
TOLER Convergence tolerance for the iterative solver (
SOLVER= 0 or 2). Defaults to 0.1.If
TOLER≥ 0, the value is interpreted as an absolute tolerance. IfTOLER< 0, it is interpreted as a relative tolerance.-
OVERRLEX Over-relaxation factor applied to the iterative solver (
SOLVER= 0 or 2). Defaults to 0.1.-
--,--,--,-- Unused fields
-
MAXFLUXITER Maximum number of flux iterations to be performed according to the specified solver type:
0
—
If the FULL solver is specified (THOPT,FULL), convergence criteria are monitored and iterations are performed until convergence occurs. If the QUASI solver is specified (THOPT,QUASI), convergence criteria are ignored and one iteration is performed. This value is the default.
1, 2, 3, ...N
—
If the FULL solver is specified (THOPT,FULL), convergence criteria are monitored and iterations are performed until convergence occurs, or until the specified number of iterations has been completed, whichever comes first. If the QUASI solver is specified (THOPT,QUASI), convergence criteria are ignored and the specified number of iterations are completed.
To view
MAXFLUXITERusage illustrations, see Figure 3.5: FULL Solution Method When Radiosity Is Present and Figure 3.6: QUASI Solution Method When Radiosity Is Present.
Notes
The radiation heat flux is linearized, resulting in robust convergence.
The radiation flux norm for FLUXTOL is expressed as:
For a sufficiently small absolute tolerance value, relative tolerance converges in fewer iterations than absolute tolerance. For a sufficiently large absolute tolerance value, relative tolerance may cause convergence difficulties.
For more information about FLUXTOL and MAXFLUXITER usage, see Figure 3.5: FULL Solution Method When Radiosity Is Present and Figure 3.6: QUASI Solution Method When Radiosity Is Present in
the Thermal Analysis Guide.
In Figure 3.5: FULL Solution Method When Radiosity Is Present and Figure 3.6: QUASI Solution Method When Radiosity Is Present (under Solving for Temperature and Radiosity in the Thermal Analysis Guide), refer to the KQQ = FQ equation system via the iterative method:
If
TOLER≥ 0, the iterative solver is converged for maximum value over a differentjas shown:
If
TOLER< 0, the iterative solver is converged for maximum value over a differentjas shown:
where:
j= number of radiation facetsk= number of iterations (k= 1 toMAXITER)
The Jacobi solver (SOLVER = 2) is
suitable when using Distributed ANSYS. This option is only available
for 3-D models; if SOLVER is set to 2 for
a 2-D analysis, the Gauss-Seidel iterative solver (SOLVER = 0) is used.