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rudelmops November 9, 2012 07:06

Dynamic Mesh: Deforming Problem
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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?

Marion November 9, 2012 08:56


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?


rudelmops November 9, 2012 10:12

2 Attachment(s)

the shaft (wall) moves to the right. So the hole grid should be deformed to the right when I preview mesh motion.

Marion November 9, 2012 10:23

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.


Marion November 9, 2012 10:24

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.


rudelmops November 9, 2012 11:00

1 Attachment(s)

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.


Marion November 9, 2012 11:07

Ok, but when you changed from 2D to 3D, did you define the geometry of the deforming walls?

rudelmops November 9, 2012 11:52


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.


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