[Aysiyi]

hi
guys ,i am now simulating a centrifugal compressor in FLUENT 14, in the process , i have a question , which turbulence model is better for turbomachinery? in the fluent training document ,i found that realizable k-ε is recommended in turbomachinery .

so what do you think ? can you share your opinion?
thanks

[cric92]

There might be no correct answer when RANS is concerned. K-epsilon model is not good capturing separation. Realizable K-epsilon is better then standard K-epsilon. If you can mange y+~1 you should go for SST K-omega.

[cfd seeker]

SST kw is generally recommended for turbo-machinery applications. According to my experience there is always a transition in turbo-machinery flows but 2 Equations RANS models are not capable of predicting transition. However Fluent has introduced two new turbulence models for transition prediction i.e k-kl-w transition (3 eq.) model and Transition kw (4 eq.) model but their mesh requirements are very stringent in the boundary layer(i.e wall y+ <1) and also out of the boundary layer( sufficient mesh resolution in the stream-wise direction and small growth of mesh size away from the boundary layer).
Hope it helps you

Regards

[Aysiyi]

Originally Posted by cric92

There might be no correct answer when RANS is concerned. K-epsilon model is not good capturing separation. Realizable K-epsilon is better then standard K-epsilon. If you can mange y+~1 you should go for SST K-omega.

i will try ,3k

[kbaker]

I saw new phenomena in FLUENT forum and i m not sure if it exist in other CFD- forums i.e. at the last few days we hear that somebody design a software called it the name he like and start send declarations about it for getting money? I am wondered this forum is free so why these people permitted to ask for money and not share there knowledge (if they really experts) freely? I hope forum moderators give an opinion about this?

Originally Posted by cfdman7

Hi dears,
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