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how to decide viscosity for DNS

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Old   January 21, 2003, 23:54
Default how to decide viscosity for DNS
  #1
Jen
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Hi, folks,

I am new to DNS. I try to figure out how to choose viscosity for DNS. I am using pseudospectral method.

Thanks,

Jen
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Old   January 22, 2003, 01:33
Default Re: how to decide viscosity for DNS
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Chai
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Hi,

If it is DNS, viscosity should be based upon physics rather than "chosen", IMHO. Hope it helps.

Chai
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Old   January 22, 2003, 04:16
Default Re: how to decide viscosity for DNS
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Tom
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What kind of flow do you want to simulate? In case of channel flow people chose their grid in terms of y^+ units. In case of isotropic turbulence k_max * Kolmogorov length scale should be equal or smaller than one. But that depends also on what kind of statistics you want to compute.

Tom
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Old   January 22, 2003, 09:13
Default Re: how to decide viscosity for DNS
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Praveen
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It is more natural to decide on a Reynolds number of your interest rather than the viscosity. Then use the equations in the non-dimensional form.
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