General

General

How can I prevent solution accuracy from deteriorating if I decrease the time-step size of the sliding mesh and moving reference frame model?

    • FAQFAQ
      Participant

      ANSYS Fluent uses some simplification for accounting transient terms in rotating sliding mesh /rotating reference frame for the Rhie-Chow face flux. It is implemented to fix some classes of problems in which the solution becomes unphysical. However, for some problems, the simplification causes adverse effects on the transient accuracy, and the solution becomes less accurate with smaller time steps. In order to avoid this issue and to fully account for the equations’ transient terms, set the rp variable in Fluent via the following TUI command: (rpsetvar ‘pressure/unsteady-rc 2) It forces full accounting of unsteady terms in Rhie and Chow no matter the kind of flow. To revert back to automatically detecting rotation and using the simplification, set it to Option “1”.