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Old   May 17, 2012, 19:18
Default comparison with DNS
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hars
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I have been trying to perform CFD analysis of isotropic turbulence using LES like scheme. In order to compare my results with DNS,should I be finding the parameters like intergral length scale(to find turn over time) from my scheme or take the DNS value. Thanks a lot......
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Old   May 18, 2012, 04:17
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Filippo Maria Denaro
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Quote:
Originally Posted by hars88 View Post
I have been trying to perform CFD analysis of isotropic turbulence using LES like scheme. In order to compare my results with DNS,should I be finding the parameters like intergral length scale(to find turn over time) from my scheme or take the DNS value. Thanks a lot......
compare the statistics (RMS, energy spectra), also total energy decaying (if your case is not forced) in time
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Old   May 18, 2012, 17:44
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Hi, thanks a lot for the reply.... when i want to plot the total energy for example, the time axis is generally non-dimensionalized which involves a length scale(integral length scale). should i obtain this value from a DNS or calculate from my code?... thnx a lot
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Old   May 19, 2012, 04:16
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in homogeneous isotropic flows the characteristic lenght scale is generally the Taylor micro-scale lambda, on whcih the Reynolds number of the computation is based too. Use information from DNS as in LES you have a cut-off of the smallest scales (only scales in the inertial range are computed) and you cannot compute the Taylor length.
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Old   May 21, 2012, 18:37
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thanks a lot for clarifying......
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