|September 24, 2012, 05:45||
Convergence pressure correction equation
Join Date: Dec 2011
Location: Madrid, Spain
Posts: 134Rep Power: 8
Dear all, I finally got my little CFD code to work (FVM, SIMPLE method, steadyflow, 2D incompressible code for the lid-driven cavity problem). However I'm experiencing some convergence issues.
I'm using upwind discretization for the convective terms and Gauss-Seidel + relaxation (SOR) solution method. I am having a hard time making the pressure correction to converge.
In each iteration of the SIMPLE method loop I update the velocity and pressure field like this:
, where u and v are the velocity components, p is the pressure, ustar, vstar and pstar refer to the guessed velocity and pressure fields and alpha_p is a relaxation coefficient I use to avoid instabilities.
For a 20cell x 20cell grid and Reynolds number 100 I am obliged to use an extremely low value for alpha_p (alpha_p = 0.01).
Did anyone found the same problem? Do you think this is a normal value for the relaxation coefficient? If you computed the same problem, which value of alpha_p did you use?
Thank you in advance for your help.
P.S: The code seems to work well for coarse grids, but it seems impossible to me to compute larger grids, it does not converge.
|Thread||Thread Starter||Forum||Replies||Last Post|
|Calculation of the Governing Equations||Mihail||CFX||7||September 7, 2014 06:27|
|changing the coefficients of pressure correction||Noel||Phoenics||1||April 7, 2009 08:54|
|Pressure Correction Equation||morteza||OpenFOAM Running, Solving & CFD||2||September 4, 2007 06:16|
|Does star cd takes reference pressure?||monica||CD-adapco||1||April 19, 2007 11:26|
|Two-Phase Buoyant Flow Issue||Miguel Baritto||CFX||4||August 31, 2006 12:02|