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Old   April 8, 2007, 12:42
Default random les inlet
  #1
Flo
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Hi,

in LES random (uncorrelated) turbulent fluctuations dissipate before the 'turbulence' developes further. So a random inlet is not recommended in LES calculations... but where in the LES equations can I see the dissipation of uncorrelated fluctuations?

Regards! Flo
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Old   April 9, 2007, 03:47
Default Re: random les inlet
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tom
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Hi,

Compute the ratio of the resolved kinetic energy and the SGS dissipation for uncorrelated fluctuations. This is a time scale which will be very short for uncorrelated fluctuations (the GS strain rate is very high) implying that the eddies dissipate quickly.
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Old   April 15, 2007, 12:36
Default Re: random les inlet
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Flo
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Hi tom,

thanks for your advice! Do you have any reference, where I can find a bit more about your explanation? I am bit confused... Those high frequencies probably can produce some 'trouble' with the discretization, too!? But this counts probably for every turbulent flow.

Flo
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