VFSM

VFSM

VFSM, Action, ENCL, OPT, MAXITER, CONV
Adjusts view factor matrix to satisfy reciprocity and/or row sum properties.

AUX12: Radiosity Solver

Action

Action to be performed:

Define	—	Define a view factor summation (default)
Clear	—	Resets the scaling method to 0 for all enclosures. All subsequent arguments are ignored.
Status	—	Outputs the `OPT` value for each enclosure in the model.

ENCL

Previously defined enclosure number for the view factor adjustment.

OPT

Option key:

0	—	The view factor matrix values are not adjusted (default).
1	—	The view factor matrix values are adjusted so that the row sum equals 1.0.
2	—	The view factor matrix values are adjusted so that the row sum equals 1.0 and the reciprocity relationship is satisfied.
3	—	The view factor matrix values are adjusted so that the reciprocity relationship is satisfied.
4	—	The view factor matrix values are adjusted so that the original row sum is maintained and the reciprocity relationship is satisfied.

MAXITER

Maximum number of iterations to achieve convergence. Valid only when OPT = 2 or 4. Default is 100.

CONV

Convergence value for row sum. Iterations will continue (up to MAXITER) until the maximum residual over all the rows is less than this value. Valid only when OPT = 2 or 4. Default is 1E-3.

Notes

To have a good energy balance, it is important to satisfy both the row sum and reciprocity relationships. For more information, see View Factors in the Mechanical APDL Theory Reference.

OPT = 1 and 2 are suitable for perfect enclosures. OPT = 1 is less expensive than OPT = 2 because no iterations are involved. However, with OPT = 1, the reciprocity relationship is not satisfied.

OPT = 3 and 4 are suitable for leaky enclosures. OPT = 3 is less expensive than OPT = 4 because no iterations are involved. However, with OPT = 3, the original row sum is not maintained.

The VFSM command must be used before VFOPT is issued, or Solve is initiated.

Menu Paths

This command cannot be accessed from a menu.