Fluent cavitation
 

Hi everybody. I'm trying to model cavitating flow through two orifices in series. I've token all the boundary conditions from the tutorial cavitation example. Have already tried all the suggested (at least I think so) changes from 22.5.3. The results: Floating point error: invalid number. Residuals sky high. Please help.

Re: Fluent cavitation
 

Hi; You only can get correct results with fluent6.1 to up. Cavitation model of fluent5, does'nt have condensation term and fluent6.0 has difficalt numerical convergence problem. A good initialization is very important in work with cavitation option of fluent. You must start calculations with a non-cavitating condition(turn on cavitation model) assitiated with a high pressure or a low velocity. Then decrease pressure or increase velocity slowly until to reach cavitating condition. Do not play more with under relaxation factors. Do not set them below 0.2 .Set vaporization factor of density and vaporization factor near one because a low relaxation for these parameter causes nonrealastic cavitation unsteady bahavior. Do not try to work with steady calculation. For steady or unsteady problems, you have to work with unsteady calculation.

Hope this help you ROOZBEH