CFD Online Discussion Forums - LES: Turbulent Channel Flow without initial solution (BC)

Quote:

Originally Posted by Lieven (Post 443445)

Hi Danesh,

Were you already using the channelFoam solver? Cause based on the fact that you mentioned you were using RAS profiles I assumed you were not (channelFoam accepts only LES turbulence models). If you are, you are correct the pressure gradient should be imposed already based on comparing the actual mean flow rate with the requested mean flow rate (from the transportProperties).

But if you are using pisoFoam, you need to include tis pressure gradient yourself in the equation. You can follow either this approach, so imposing a flow rate, or you can directly set 'gradP' as a fixed value.

Cheers,

Lieven

Dear Lieven

Is it possible to solve a nozzle with the concept used in the channelFoam?
I mean I guess cyclicBC & gradpPlus used in the solver is the combination that generates turbulence in your field when using LES. If I am wrong tell me.
When the area in the inlent and outlet are not the same, then u cant use cyclic. without cyclicBC and using channelFoam it is likely to end up in a Poiseuille flow result (by using pisoFoam),
Then how can u solve this problem. I mean simulation of flow in a nozzle using LES.

Regards

Ali