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k-e model limits

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Old   September 9, 2009, 09:25
Default k-e model limits
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fateme chegini
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Hi

I'm trying to implement the k-e model in my code. The problem is I don't know what is the limiting value for k and e. In some problems the min values I use (ie:kmin=10^-6 & emin=10^-5) yield to correct answers but when the geometry is very unregular my model becomes unstable and the viscosity grows. I would rather not put an upper limit for k although I know this is conventional. Do you think I can do that or am I obliged to implement a max bound for k or viscosity?

Does anyone know of a good refrence that has discussed about the limiting values of k and e?

Thanks very much.
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Old   September 9, 2009, 13:45
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I have the same situations, sometime the ratio of k/e play a big role.In my case, in some regimes, the velocity is very small and also the strain rate.. etc, and K and E are reasonable values (very small). But the eddy viscosity have a big value due to K**2/E.
Can anyone give some suggestions?
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