turbDyMFoam and Convergence
I have used icoDyMFoam to run a turbomachinery case (I was learning to use OpenFOAM, mesh, etc.), and obviously it did not converge.
So I have been trying to implement turbDyMFoam. I have downloaded the files found here: http://openfoamwiki.net/index.php/Si...vaned_diffuser
And transplanted the controlDict, RASProperties, transportProperties, fvsolution, and fvscheme files to my (originally icoDyMFoam) case. I also put boundary conditions on the inlet (freestream) flow (I am doing an external flow with a rotating part) for k and epsilon (zerogradient for everywhere else).
The simulation runs at least, but soon diverges (floating point exception, huge velocity magnitudes).
Can anybody give me a guide to the parameters I can adjust to get convergence?
Thanks in advance.
I get these figures:
It is actually running, and I am only getting floating point exceptions, so I guess that means only the initial conditions are bad. I have tried:
None fail to diverge.
Posting working cases of turbulent external flow using turbdymfoam would be highly appreciated.
I'm trying turbDyMFoam with ggi on wind turbine analysis and it's working well.
I use RAS kOmegaSST turbulence model.
Have you good mesh (especially in nonOrthoFaces check)?
Are your turbulent parameters internalField values correct?
Hello Andrea, thanks for your reply.
I ran 'checkMesh' and it said that one mesh check failed. I could not discern what exactly this was from the terminal outputs. 'Non-orthogonality check OK.' ; is this what you were talking about? I posted the entirety of the terminal message below.
I have also posted below my initial condition files for k and epsilon. I calculated them using the common formulas. The boundary types in those files are not the only ones I have tested.
Could I take a look at your fvsolution, fvscheme, and /0/ files for k, epsilon, and omega?
Have you tried using RNGkepsilon?
fvSolution tolerance and reltol
Running komegaSST, I no longer get floating point exceptions (at least not yet). However looking at the output through paraFoam, things are still crazy.
I stumbled upon this thread: http://www.cfd-online.com/Forums/ope...timesteps.html , I started to increase tolerance of p's reltol. That decreased the amount of bounding messages, though they still appear.
So I was wondering, can anybody explain how to adjust the fields in fvSolution (preconditioner, tolerance, reltol) to get better convergence and accuracy? Here is a relative section in the OpenFOAM manual: http://www.openfoam.com/docs/user/fvSolution.php
(I am looking into it myself of course, I put this up so that a solution may be worked towards in parallel)
Ok, so I have decided to set all 'reltol's to zero, that way we only have to worry about the 'tolerance'.
Do I need to mess with the preconditioners?
My system files so far:
|All times are GMT -4. The time now is 19:39.|