|
[Sponsors] |
Understanding pimpleFoam convergence criterion |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
March 13, 2013, 19:46 |
Understanding pimpleFoam convergence criterion
|
#1 |
Member
|
Hi, I have a question about convergence criteria for pimpleFoam. I read other relevant threads but couldn't find a clear answer.
My understanding is that with the simpleFoam solver, it is necessary to run until the 'p' residuals drop at least three orders of magnitude (1e-3) and the 'U' (Ux, Uy, & Uz) residuals drop about four to six orders of magnitude (1e-4 - 1e-6), then stop changing. I'm now using pimpleFoam to obtain a transient solution (different boundary conditions). My understanding is that in this case, both the 'p' and 'U' residuals must drop around one order of magnitude per time step. My questions: 1) Should the initial residuals drop below a certain threshold before the transient solution is considered accurate? I saw in other threads that this was mentioned, but I saw no discussion on how this criterion is determined. If this is true, are pimpleFoam solutions always wrong during start-up? I don't really understand this. 2) How do you determine the criterion for how much the residuals should drop per time step? Thank you community! -Nuc |
|
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Convergence | Centurion2011 | FLUENT | 48 | June 15, 2022 00:29 |
problem with Min/max rho | tH3f0rC3 | OpenFOAM | 8 | July 31, 2019 10:48 |
Force can not converge | colopolo | CFX | 13 | October 4, 2011 23:03 |
convergence criterion | Dominique | FLUENT | 5 | November 24, 2006 03:36 |
Setting convergence criterion | Vidya | FLUENT | 5 | August 6, 2006 17:46 |