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[ANSYS Meshing] Problem in convergence due to poor mesh quality

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Old   June 11, 2019, 00:48
Exclamation Problem in convergence due to poor mesh quality
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Abhishek Dahiya
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I am trying to simulate a ceiling fan using the sliding mesh technique. The fan is of 24-inch dia, a cylindrical rotating domain encloses the fan and enclosure(room) is 10*10*9 feet. I have tried many meshing techniques. Most of them give an error "mesh could not be generated with given input". meshing was successful using patch conforming tetrahedral but the minimum orthogonal quality is of the order of 10^-9 and maximum aspect ratio of 10^3. I am sure this is the reason for divergence error.

I have tried all the resolution of mesh and different element size, from total elements value of around 900000( min element size - 200 mm) to around 30000000 ( with min element size of 10 mm and 2 refinements at blades of fan in the rotational domain). there is a little change in the numbers of orthogonal quality and aspect ratio.

The geometry is pretty smooth and simple. don't think there should be any problem because of that.

Please Help!
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Old   June 14, 2019, 20:01
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Ioannis Tsavlidis
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Hi dahiya3806,

Can you please post a picture of your geometry just to get an idea?

Best,
Ioannis
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Old   June 14, 2019, 23:53
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Abhishek Dahiya
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I am able to get the orthogonal quality up to 0.015 by removing bolts and holes but that's still not good enough. The case diverged after 350 iterations (11-time steps of 0.001 sec). Should I go for an even smaller time step?
No. of elements in mesh - around 2,600,000. Rotating domain velocity - 350 RPM. I am using the K-E turbulence model.
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aspect ratio, divergence amg solver, orthogonal quality, sliding mesh method

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