General

General

How can you improve the convergence locally in a specific domain in the CFX?

    • FAQFAQ
      Participant

      Below is the trick to improve convergence of specific equation in specific domain. It did help in the past in multiphase calculations. Basically it stabilize the calculation of velocities by adding a false time step terms as a source term to the momentum (and, possibly, the volume fraction) equations. The convergence can be locally improved by setting a source term for a subdomain that covers a specific domain with slow convergence. The value of the source term should be zero, whereas the source coefficient is set to density/timescale. Where timeScale is the (short) fluid timescale. This trick strengthens the diagonal of the matrix and therefore speeds up the convergence.