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Dynamic Mesh: Deforming Problem

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Old   November 9, 2012, 07:06
Default Dynamic Mesh: Deforming Problem
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Christopher Mai
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Hello,

I'm simulating the flow of a journal bearing. I created a grid for the bearing gap with ICEM.
My problem is that only the layer of cells nearest to the shaft are deforming although I used the command: define/dynamic-mesh/controls/smoothing-parameters/s-o-a-s.
Can anybody help me with this?
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Old   November 9, 2012, 08:56
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Hi,

In which direction is the wall supposed to move?
Could you put an image of the whole domain to get a better idea of your issue?

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Old   November 9, 2012, 10:12
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Hi,

the shaft (wall) moves to the right. So the hole grid should be deformed to the right when I preview mesh motion.
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Old   November 9, 2012, 10:23
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Ok, in the smoothing options try increasing the number of iterations (500), decreasing tolerance (0.0001).
Then play with the spring factor. if it's close to 1 I think it only moves nodes close to the moving wall and when it's close to 0 the nodes further away are moved (or is it the contrary? sorry I have to check).
I personnaly use 0.4 for the spring constant.

Maybe hex mesh is not the best for this kind of motion though... except if the displacement is very small.

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Old   November 9, 2012, 10:24
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Also: don't forget to put EVERYTHING that is deforming as deforming zones: fluid domain + walls or other Boundary Conditions.

If you have nodes on a cylinder that are supposed to be deforming then you should put the cylinder equation in the "geometry" tab.


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Old   November 9, 2012, 11:00
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Christopher Mai
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Hi,

the problem is that only that one layer of cells deform. Adjusting the smoothing options doesn't change that. I did this bearing in 2D and it worked fine. I'm not simulating yet, I just want the whole mesh to deform.

The picture attached shows the deformed mesh of the same bearing gap in 2D.

~Chris
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Old   November 9, 2012, 11:07
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Ok, but when you changed from 2D to 3D, did you define the geometry of the deforming walls?
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Old   November 9, 2012, 11:52
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Hi,

the problem is the mesh. I couldn't find the mistake so I started from scratch and now it works perfectly. Thanks for your help though.

~Chris
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