mffr

Mapdl.mffr(fname='', lab='', rfini='', rfmin='', rfmax='', **kwargs)

Setup Multi-Field relaxation factors for field solutions.

APDL Command: MFFR

Parameters:

fname

Field name (MFX) or number (MFS). Must be the ANSYS field (cannot be a CFX field).

lab

Label name. Valid values are DISP and TEMP.

rfini

Initial relaxation factor. Defaults to 0.75.

rfmin

Minimum relaxation factor. Defaults to RFINI.

rfmax

Maximum relaxation factor. Defaults to RFINI.

Notes

Use this command to relax the field solutions in fluid-solid interaction analyses and thermal-thermal analyses for a better convergence rate in coupled problems, especially cases that need dynamic relaxation. The ANSYS field that has the MFFR command applied will do only one nonlinear stagger iteration within each multi-field stagger; the convergence of the ANSYS field solver will be satisfied through multiple multi-field staggers. Note that the CFX field solver can have multiple iterations within the field solver; see the CFX documentation for more details. ANSYS will not terminate the nonlinear field solution until the ANSYS field solver converges or reaches the maximum number of multi-field staggers as specified on MFITER.

The interface load relaxation (MFRELAX) will be automatically turned off for the corresponding surface loads that have MFFR applied. The automatic change of the relaxation factor for accelerating the nonlinear convergence of the coupled field solution is based on Aitken’s acceleration scheme.

This command is valid only with coupled problems involving surface load transfer only. No subcycling is allowed for the field solver if using this command.