LES filtering question

martyn88 · October 16, 2012, 19:54

Hi everyone,

I am confused by the filtering operation in LES. I am running an LES of a turbulent free jet using the oneEqEddy SGS model and a cube root volume delta.

How is the filtering operation applied in this case? Is it being filtered by my grid (are the SGS stresses calculated based on local grid spacing) or is there an explicit filtering step taking place?

Thankyou

morard · October 18, 2012, 04:08

Hi martyn88

In your case, the filtering operation is not applied at all. Filtering is applied just in dynamic models, like dynOneEqEddy, and it is done by averaging over the cell.

Regards,
Dejan

October 16, 2012, 19:54	LES filtering question	#1
martyn88 Member Hugh Ingham Join Date: Aug 2012 Posts: 35 Rep Power: 14	Hi everyone, I am confused by the filtering operation in LES. I am running an LES of a turbulent free jet using the oneEqEddy SGS model and a cube root volume delta. How is the filtering operation applied in this case? Is it being filtered by my grid (are the SGS stresses calculated based on local grid spacing) or is there an explicit filtering step taking place? Thankyou

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October 18, 2012, 04:08		#2
morard Member Dejan Morar Join Date: Nov 2010 Posts: 78 Rep Power: 17	Hi martyn88 In your case, the filtering operation is not applied at all. Filtering is applied just in dynamic models, like dynOneEqEddy, and it is done by averaging over the cell. Regards, Dejan