Domain Related Parameters

• After entering X-Max/Min and Y-Max/Min, the prompt asks for Mesh size - [dx dy]. This defines how fine is the discretised mesh. In general a finer mesh will be generate more accurate results, and will take longer to compute.

Density, Viscosity

• The Fluid is characterized by Density & Viscosity in the program.

Under-Relaxation Factors

• These are dampening factors used with coupling algorithms. The purpose is to avoid diverging solution for steady state simulations. The values mentioned below for SIMPLE algorithm are advised by renowned CFD authors like Peric, Roy Chowdhury, Versteeg & inventor of SIMPLE algorithm Mr. Suhas Patankar.

  • Under-Relaxation Factor for Velocity
    • 0.6-0.8
  • Under-Relaxation Factor for Pressure
    • 0.2-0.5

  It's advised to check multiple values for best Residual behavior.

Maximum Iterations and Min Mass Residual

• The steady state SIM will run for this value, unless the Mass Residual drops below Min Mass Residual.
  • Example values are 100 & -4.