[shipman]

Hi to all,

Addition to my above question, i would like to ask one more thing. As you can see in the attached figures, I did calculation using different turbulent models (keps and kwSST) with the interphasechangeFoam. First of all, i initiliazed flow fields for both cases, than for k-eps i used upwind discretization. As seen in the first fig., evertying seems to go well, however after t=0.0145 there are rapid jumping in the initial residual of alpha and P.

On the other hand, for kw-SST i used TVD scheme, and as seen in 2nd fig, after t=0.0118 there is rapid decline in the alhpa residual. Could someone have any idea why these rapid and decline take place nearly at the end of the calculation?

Thanks in advance.

B

[wyldckat]

Greetings Baris,

I've moved this post of yours from the other thread: http://www.cfd-online.com/Forums/ope...g-gnuplot.html - because the question isn't as related to the original topic and it was less likely that you would get and answer to either one of the issues.

As for your question on this thread, without more information, I can only guess the following:

• The mesh might be at blame here, in case there are any very small and/or distorted cells.
• The other possibility is that in the simulation with the instability, there was a high speed vortex that appeared, then released it's vortex and then died down.

My advice is that when diagnosing these issues, you take the approaches demonstrated by the examples given here: OpenFOAM: Interesting cases of bad meshes and bad initial conditions

Best regards,
Bruno