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CFLFactor Command

The CFLFactor command sets the "Courant-Friedrichs-Levy" factor for an MPM analysis:

CFLFactor (factor),(transportFactor)

The (factor) parameter sets the "Courant-Friedrichs-Levy" factor used to determine the maximum time step that is allowed. See OSUPDocs wiki for details. If this command is not used, the default <fraction> will be 0.5; it must be less than 1 and smaller is needed for some simulations, especially when boundary condition problems arise.

The (transportFactor) parameter sets a "Courant-Friedrichs-Levy" for checking time step when solving transport equations (such as conduction or diffusion). Because the transport time step is almost aways much longer than the mechanics time step, this factor is rarely used. It is important, however, when running OSPartiulas in "Transport Only" mode.

Notes

  1. The "Courant-Friedrichs-Levy" factor can alternatively be set in a TimeStep Command.
  2. The CFLFactor command is only allowed for MPM analyses.