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Old   October 18, 2016, 02:08
Default Convergence problem
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engeagle
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Hello,

I'm new with Fluent, so I have some problems. Actually, my analysis is very simple. laminar and cold flow. I generated two different mesh for this analysis. the mesh number for one of them is 250000, the mesh number of other 1100000. When I used the model which has 250000 mesh number, I don't have any problems. It converges. On the other hand, other model doesn't converge. I consider that the mesh quality is enough. maximum skewness is 0.79. I use same boundary conditions for two models.

How can I solve this problem?

Thank you.
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Old   October 18, 2016, 04:18
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Quote:
Originally Posted by engeagle View Post
Hello,

I'm new with Fluent, so I have some problems. Actually, my analysis is very simple. laminar and cold flow. I generated two different mesh for this analysis. the mesh number for one of them is 250000, the mesh number of other 1100000. When I used the model which has 250000 mesh number, I don't have any problems. It converges. On the other hand, other model doesn't converge. I consider that the mesh quality is enough. maximum skewness is 0.79. I use same boundary conditions for two models.

How can I solve this problem?

Thank you.
does it necessary to finer mesh ?
much number of mesh didn't mean better result often. you face to truncation error
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Old   October 18, 2016, 04:40
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does it necessary to finer mesh ?
much number of mesh didn't mean better result often. you face to truncation error
I want to evaluate mesh independency, so I generated finer mesh.
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Old   October 18, 2016, 04:45
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I want to evaluate mesh independency, so I generated finer mesh.
well , how much is the dimension of your problem ?
i guess jumping from 250000 to 1100000 is big.
500000 is enough for next level
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Old   October 18, 2016, 05:43
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well , how much is the dimension of your problem ?
i guess jumping from 250000 to 1100000 is big.
500000 is enough for next level
Thank you for answers.

My geometry is 1/4 of a cylinder. The height of the cylinder is 1000 mm and the diameter is 75 mm.
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