Turbulence Model Problems
 

Hello All
I'm having a problem on Fluent when I switch from k-e r to a k-w sst model. When I used the k-e model I had no problems and I obtained a solution fine. Now that Ive changed to the k-w sst my solution keeps diverging although everything else is kept the same from the previous model. Any ideas of why this is and how to solve it?

Thanks for your help

turbulent models must be chosen according to the flow type. The mesh need to be changed too...

heidar
 

in fluent the K-w turbulence model uses one eqution model to resolve the flow structure near wall. whereas the K-e model can uses the 3 type of near waal solution. using one eqution model for near wall treatments leads us to beter results but u have to increase the mesh density.
ok go on and increase mesh density
but be care that now u could not compaire the two answer of K-e and K-w.
bye :D

Yplus
 

Check values of yplus ....
If you have seperated flow try SST but be sure to have low yPLUS ~1 (i guess).

SST uses kw in near wall and ke in inner region ....
In case you dont have seperation better use ke , computationally good
Regards
Ali