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Old   June 6, 2012, 06:51
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Hello

This discussion is about DNS and is not pertaining to any particular tool.

Usually, DNS is carried out in spectral space, especially when it comes to homogeneous turbulence. However, I would like to have your opinion about the "Implications that could arise out of carrying out DNS in physical space".

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Vinerm Andrews
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Old   June 6, 2012, 07:21
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Originally Posted by vinerm View Post
Hello

This discussion is about DNS and is not pertaining to any particular tool.

Usually, DNS is carried out in spectral space, especially when it comes to homogeneous turbulence. However, I would like to have your opinion about the "Implications that could arise out of carrying out DNS in physical space".

Regards,
Vinerm Andrews
no implication at all ... Assuming that DNS means that you must solve for all the characteristic flow scales, you can use SM, FD, FV, FEM ....
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Old   June 6, 2012, 14:30
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Quote:
Originally Posted by vinerm View Post
Hello

This discussion is about DNS and is not pertaining to any particular tool.

Usually, DNS is carried out in spectral space, especially when it comes to homogeneous turbulence. However, I would like to have your opinion about the "Implications that could arise out of carrying out DNS in physical space".

Regards,
Vinerm Andrews

As long as you can guarantee that you are doing a real DNS with all scales resolved, there's no difference at all. Just note that with non-spectral methods you will probably need more DOF to be numerics-free than with a spectral approach!
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Old   June 6, 2012, 16:09
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DNS in pipes is most commonly (assumed to be) done with second order spatial schemes.
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Old   June 6, 2012, 16:55
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just to add that DNS performed in physical space is practically the only way to face non-simple geometry
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Old   June 10, 2012, 03:47
Default Homogeneous and Non-homogeneous
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Hello Everyone

Thank you all for your replies. As far as I have been able to resolve by studying papers and books, spectral methods have issue in resolving non-homogeneous turbulence but whether geometry is complex or not does not really matter. However, I am still not even a beginner with DNS. I have just read a few papers about it. So, thank you all.

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