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student2 January 28, 2011 05:44

treating unresolved scale
 
Hello, every one.
I have a question with filtering in LES.

Let original flow u and filtered flow <u>.
Then unresolved scale become u'=u-<u>

If I filter the unresolved scale, i.e., <u'>,
I want to know whether this value will be 0 or not?

Thank you for reading!
YE.

sbaffini February 14, 2011 14:34

The answer is "no", unless you use a projective filter. Try by yourself in MATLAB with a simple 1D function (sum of sines) and different filters. The spectral cut off is the only filter which gives exactly 0.

student2 February 14, 2011 21:51

Thanks, Sbaffini!
 
Quote:

Originally Posted by sbaffini (Post 295224)
The answer is "no", unless you use a projective filter. Try by yourself in MATLAB with a simple 1D function (sum of sines) and different filters. The spectral cut off is the only filter which gives exactly 0.


Thank you for your help!


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