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-   -   numerical diffusion & patch operation (http://www.cfd-online.com/Forums/fluent/87042-numerical-diffusion-patch-operation.html)

ronen April 10, 2011 02:02

numerical diffusion & patch operation
 
1. What are the options available to avoid numerical diffusion?

2. When I patch a small volume I get an avaraged value of the specified parameter at the marginal grid of the volume. How can I avoid it?

Thx :)

Amir April 10, 2011 09:57

it doesn't occur if you display cell values not node values. (you can set that in display->contour)

ronen April 10, 2011 12:17

Thx for the quick replay, the tip helped and works :)
What about the Numerical diffusion? The mesh is refined and the results are still exhibit significant false diffusion which is beyond the resonable for the mesh size. What can I do about that?

Amir April 10, 2011 12:25

Quote:

Originally Posted by ronen (Post 302975)
Thx for the quick replay, the tip helped and works :)
What about the Numerical diffusion? The mesh is refined and the results are still exhibit significant false diffusion which is beyond the resonable for the mesh size. What can I do about that?

I just know that some numerical algorithms and schemes have numerical diffusion behavior because of their definitions, if you describe your problem clearly, I may help you.

ronen April 10, 2011 17:44

I managed to perform LES(Smagorinsky-Lilly).
Now I would like to model species transport.


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