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Old   December 21, 2005, 00:50
Default grid independence
Muhammad Shakaib
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Dear Fluent users

When I run my 3d-case with three different grids (26000, 86000 and 247000 cells) the difference in velocities and pressure was approx. 8% between the first two mesh sizes (i.e. 26000 and 86000 cells) and the difference is less than 3% for the 86000 and 247000 cells. Is my solution with 86000 cells grid independent.
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Old   December 21, 2005, 03:38
Default Re: grid independence
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No, of course not. Maybe you should try a 400,000 cells grid and compare results to the 247,000 cells grid. Then you will be able to say what grid is enough. Anyway, 86,000 cells grid for a 3D case seems too small to me! I have calculated cases with grids of 800,000 cells and found them to be only acceptably grid independent. So, be careful!

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Old   December 27, 2005, 21:27
Default Re: grid independence
Chetan Kadakia
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I would say your 247,000 cell mesh might be near grid independent. What are you modeling? 400,000 to 800,000 may be better. It's hard to call grid independence, because sometimes grid resolution can determine the ability to predict certain flow features that can noticably change results.
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