Problem with INTERPHASECHANGEFOAM
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Dear Foam users,
i am studying modeling of cavitation inside of the nozzle. Therefore, i tried before cavitatingFoam solver and obtained not bad result. However, i couldnt obtained transient cavitation with it, therefore i switched to use interphaseChangefoam solver by using SchneerSauer model. I am using OF version 2.1.1 and when i set the initial U and p_rgh settings according to tutorial as follow; 0/U: Code:
dimensions [0 1 -1 0 0]; Code:
Code: why cavitation starts immediately? why after 100 time step everything becomes constant? I thought that maybe mesh number problem and i tried much finer mesh with the same initial conds. same result. then i changed the conds as follow based on the inlet pressure acc. to experimental result; this time i couldnt obtain any cavitation and even sometimes alpha1 became negatif whereas with the same conditions i had really good results with cavitatingFoam. 0/U: Code:
dimensions [0 1 -1 0 0]; Code:
InternalField uniform 1e5; as addition, i checked new version of interphasechangefoam (2.2.2) and i saw new treatment as alhpa2 and there are some differences in the codes of pEqn.H, alphaEqn.H, alphaEqnSuccycle.H,.. Please could someone tell me that which version of interphasechangefoam gives good result? Or is there anyone who got resonable result before with this solver? Thnaks in advance |
Hi shipmen,
I can not give you lot of advice to the solver because I only used it to build a new solver with temperature dependend phase change. Additionally I never used cavitationFoam. You should ask yourself if your Problem can be solved with RANS / URANS. The Picture of the measurement seems to be very unsteady. Maybe you have to calculate this with LES. Additionally - what turbulence model do you use? Maybe your viscosity model fails in that case? Did you compare the results of cavitationFoam and interPhaseChangeFoam? Any differences in p, U, p_rgh, etc.? Did you use the same turbulence model in both cases, same schemes, same boundary conditions? At least (if its possible) you could extend your cavitationFoam (i think it is steady state) to transient solver. I am not so familiar with the Phase Change theory but you can test it and add the partial differential term of time to your equations. PS: did you initialize your interPhaseChangeFoam with the steady-state solution? Regards Tobi |
Dear Tobi,
I am looking for initializing a LES from RANS solution. For LES, I used pimpleFoam. It runs quite well the initial solutions in folder 0/ with the following files U, p, k, nuTilda and nuSgs. However, RANS (RNG k-epsilon) gave me also good results. The lastest time folder (iteration no. 5000, for example) contains U, p, k, epsilon, nut and nuTilda. May you give some advices to initialize pimpleFoam from the RANS solution? Thanks you in advance, vut |
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