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Old   November 4, 2003, 10:57
Default convergence problem
  #1
bylin
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I use standard k-epsilon model to compute confined jet, it just does not converge.Is this model fit for this problem?
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Old   November 5, 2003, 11:07
Default Re: convergence problem
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thomas
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Hi, I am actually simulating a 'jet'. What solver are you using (VOF, Eulerian)? and could you describe a bit more what you have to model inpinging jet on a wall, jet injection into a water bulk ????? bye thomas
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Old   November 5, 2003, 12:27
Default Re: convergence problem
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David
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have you tried to reduce the under relaxation factors?

pressure, momentum, kinectic energy, turbulence dissipation rate?

have you checked your boundary conditions?

lots of things to verify but please be more accurate in the description of your problem.

thanks
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Old   November 6, 2003, 09:42
Default Re: convergence problem
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bylin
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Oh,thank you,thomas! It's an air round jet flowing into a coaxial surrounding air flow whose velocity is much less than that of the jet.And there is an annulus bluff body surrounding the outlet of the jet.
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Old   November 6, 2003, 10:01
Default Re: convergence problem
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bylin
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Thank you,David.I'm a new comer for CFD,thanks for your advice. Reducing relaxation factors is of no use,and the solution seems to be insensitive to the boundary conditions.I suspect that the grid is not fine enough. So does refinement of the grid help?
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Old   November 26, 2003, 04:03
Default Re: convergence problem
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Volker Pawlik
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See e.g. the user's guide: it is advised to use rke-model for round jets.
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