CFD Online Discussion Forums

CFD Online Discussion Forums (
-   CD-adapco (
-   -   Relaxation and Solver Parameters (

norbinou July 9, 2007 06:11

Relaxation and Solver Parameters

I want to now if the the number of sweeps and Residual tolerance a causes for divergance (work with Star-CD 3.26)


pankaj saha August 6, 2007 05:34

Re: Relaxation and Solver Parameters
plz, can u tell, when we are using modified MAC method and solving 3d-channel turbulent flow. 1. should we use underrelax or overrelax. 2. what should be the continuity satisfying limit. 3. what shoul be the inlet velocity profile and initial condition for tha channel for turbulent flow simulation.

this is rectangular channel.

pankaj saha August 21, 2007 17:46

Re: Relaxation and Solver Parameters

actually i am not using any software...i wrote a code in fortran using SMAC solver./

so, can u plz help me to ans my question in pretext to code not in softre...

norbinou September 25, 2007 01:38

Re: Relaxation and Solver Parameters
I use underrelax 1E-04, think you should underrelax. If you have a rectangular profile, i think you should use rectangular profile @ initial velocity.

So I think you need to do that, an after you can see, if the result is correct or no, you can calculate maybe the pressure drop, an look in significant or not.

All times are GMT -4. The time now is 01:35.