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October 7, 2011, 08:12 |
how to solve negative volume?
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#1 |
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Join Date: Aug 2011
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Dear All,
I am trying to simulate 2d vortex vibration of cylinder. I just made simple 2d domain which have inlet, symmetry (top and bottom), outlet and just wall ( large domain subtracts cylinder). Then, I imposed an udf file on cylinder to move vertical motion in dynamic option. I have searched all of google sites about same problems but I cannot solve my problem. In dynamic mesh, cylinder has rigid body with udf file. 1 turn on smoothing with spring constant factor 0 and boundary node relaxation 1. 2. turn on remeshing option with sizing funtion and use defaults of parameters. I know I have something wrong in my steps but I have no idea what is wrong with. I appreciate your guys leave any comments or any ideas. Regards, |
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October 7, 2011, 11:22 |
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#2 |
Senior Member
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Hi,
Increase spring constant. Additionally, check it in display->grid; I think in newer versions, there is an option to view motion of specific parts not all of them if you faced this in solve->grid motion. Bests,
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Amir |
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October 9, 2011, 21:42 |
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#3 | |
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Quote:
I have a weird moving mesh (attached file) I assigned osc to cylinder and osc_inert to the entire fluid region (this part is in udf file) I assigned the top and bottom walls as stationary. But, the mesh wend out beyond top /bottom walls. Do you have any idea for this problem? Best Regards JY |
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October 10, 2011, 04:28 |
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#4 | |
Senior Member
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Quote:
I'm not sure that understand your problem clearly, but there are few comments on such dynamic mesh issues: - your elements are quadratic, so you have to enable moving them in smoothing method in TUI. (refer to manual) - your cylinder oscillate in y-direction, so the only thing you need is to hook DEFINE_CG_MOTION on cylinder boundary and let fluent to change other cells with smoothing method; (fluid zone doesn't need any UDF). Bests,
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Amir |
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October 10, 2011, 04:31 |
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#5 | |
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Quote:
Thanks, My problem looks like solved. Very Thanks!! |
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