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Old   January 8, 2013, 16:24
Default Meshing in CHT Problem
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I try to mesh my geometry (thin plate). The minimum orthogonal quality is about 0.1 and the average about 0.9. The residuals are about 1e-05 after 1000 iterations and can not be further reduced.
Some elements have negative value of wall heat transfer, which I cannot physically explain.
1. Is it important to use inflation or should I ignore inflation to achieve a better minum orthogonal quality?
2.Should I try to use Polyherdal meshing to improve minimum orthogonal quality? Can Polyherdal meshing be used for CHT problems? When I used Polyhedral meshing the maximum value of wall heat transfer was being almost doubled in comparison with Tetrameshing. How could you explain this?

Thank you in advance
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Old   January 10, 2013, 16:56
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Could anybody please help me?
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Old   January 13, 2013, 13:36
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Does anybody have any idea?
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Old   January 13, 2013, 13:59
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post screenshot of you mesh !! and your geometry !! is it 2d or 3d ?? what software did you use to mesh ??
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Old   January 13, 2013, 14:45
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Thnak you for yyour reply! My mesh is 3d and was made in Ansys Mesher (Workbench)
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Old   January 13, 2013, 14:57
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can i see how it looks like
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Old   January 13, 2013, 16:14
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I unfortunately don't have an availiable picture of my meshing right now, but I will post one as soon as possible! Thank you in advance for your help
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Old   January 13, 2013, 16:16
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Just to imagine it looks like an thin airfoil in a wind tunnel. Only a the fluid was being meshed (I used boolean subtraction to create the appropriate geometry).
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Old   January 13, 2013, 16:38
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it should be easy to mesh with a structured mesh under ICEM are you familiar with icem. when the geometry is easy; always go for a structured mesh if you can.
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Old   January 13, 2013, 16:45
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Thank you for your advice! I tried to do a structured mesh! Unfotunately the mesh in the area near the airfoil (cambered) can not be structured.
When I try smoothing the meshing in Fluent I got a better minimum orthogonal quality (~0.4). The simulation result remained unchanged (energy residuals do not ger below 10^-5 so I thought I should try to solve my problem transient)!
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