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November 9, 2012, 06:06 |
Dynamic Mesh: Deforming Problem
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#1 |
New Member
Christopher Mai
Join Date: Aug 2012
Location: Dresden, Germany
Posts: 5
Rep Power: 13 |
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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November 9, 2012, 07:56 |
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#2 |
Senior Member
Marion
Join Date: Jul 2012
Location: France
Posts: 122
Rep Power: 14 |
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? Marion. |
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November 9, 2012, 09:12 |
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#3 |
New Member
Christopher Mai
Join Date: Aug 2012
Location: Dresden, Germany
Posts: 5
Rep Power: 13 |
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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November 9, 2012, 09:23 |
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#4 |
Senior Member
Marion
Join Date: Jul 2012
Location: France
Posts: 122
Rep Power: 14 |
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. |
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November 9, 2012, 09:24 |
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#5 |
Senior Member
Marion
Join Date: Jul 2012
Location: France
Posts: 122
Rep Power: 14 |
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. Marion. |
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November 9, 2012, 10:00 |
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#6 |
New Member
Christopher Mai
Join Date: Aug 2012
Location: Dresden, Germany
Posts: 5
Rep Power: 13 |
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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November 9, 2012, 10:07 |
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#7 |
Senior Member
Marion
Join Date: Jul 2012
Location: France
Posts: 122
Rep Power: 14 |
Ok, but when you changed from 2D to 3D, did you define the geometry of the deforming walls?
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November 9, 2012, 10:52 |
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#8 |
New Member
Christopher Mai
Join Date: Aug 2012
Location: Dresden, Germany
Posts: 5
Rep Power: 13 |
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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