General

General

Convergence of User Defined Scalar

    • FAQFAQ
      Participant

      There might be a need to solve for User Defined Scalar(UDS) in Fluent. It has been found that in some instances, using zero diffusivity for UDS leads to NAN. Also, first-order discretization results in diverging of the run after initial convergence. Following suggestions might help in overcoming the problem. 1) Instead of zero diffusivity, use a very small number, say, and 1e-12. 2) Use double precision solver. 3) Importantly “power law” discretization helps in overcoming divergence of UDS equation.