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numerical diffusion & patch operation

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Old   April 10, 2011, 02:02
Default numerical diffusion & patch operation
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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?

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Old   April 10, 2011, 09:57
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it doesn't occur if you display cell values not node values. (you can set that in display->contour)
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Old   April 10, 2011, 12:17
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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?
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Old   April 10, 2011, 12:25
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Quote:
Originally Posted by ronen View Post
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.
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Old   April 10, 2011, 17:44
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I managed to perform LES(Smagorinsky-Lilly).
Now I would like to model species transport.
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