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Fluid flow from a pipe

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Old   July 24, 2019, 09:41
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Quote:
Originally Posted by alexeym View Post
Hi,

You can. It would be better to make new mesh with lower non-orthogonality. You should use not only increased value of non-orthogonal correctors, but also specific discretisation schemes.



Hi,


In general, does making the cell size smaller make the non-orthogonality get lower?
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Old   July 24, 2019, 14:32
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Hi,

In general, no. In fact, reducing cell size can have opposite effect.
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Old   July 25, 2019, 03:16
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Originally Posted by alexeym View Post
Hi,

In general, no. In fact, reducing cell size can have opposite effect.

Hi. actually when I had bigger cells, I was having the problem of aspect ratio and skewness as well. Then I reduced the cell size, and aspect ratio and skewness problem resolved, but still I was getting non-orthogonality.


I don't know how to reduce the non-orthogonality, my non-orthogonality is 86 degree.


I am using limited fvSchemes, but I didn't put nonOrthoCorrectors.


can putting nonOrthocorrectors help?
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Old   July 25, 2019, 08:09
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With non orthogonality 87 no non orthogonal correction would be enough.


First of all check this image:

As You can see non orthogonality is related more likely to triangular cells than rectangular cells. Try to improve Your mesh quality using different method. Especially try to use quadrangle mash if possible. I do not know which tool You are using for meshing but maybe some restrictions or smoothing would solve the problem.
Check Your mesh carefully for bad mesh and divide geometry to improve cells quality.


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Old   July 25, 2019, 08:53
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Quote:
Originally Posted by sheaker View Post
With non orthogonality 87 no non orthogonal correction would be enough.


First of all check this image:

As You can see non orthogonality is related more likely to triangular cells than rectangular cells. Try to improve Your mesh quality using different method. Especially try to use quadrangle mash if possible. I do not know which tool You are using for meshing but maybe some restrictions or smoothing would solve the problem.
Check Your mesh carefully for bad mesh and divide geometry to improve cells quality.


Best regards,
Oskar

Thank you so much for your reply.


I am using salome for meshing. Actually my geometry has around 26 different regions with different sizes and shapes. And I am using Netgen 1D-2D-3D, but I am not trying other parameters.



And one general question here, which meshing tool is better, Salome OR snappyHexMesh?


Thank you
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