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tank sloshing overflow error

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Old   January 20, 2011, 00:34
Default tank sloshing overflow error
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Hamed
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I have modeled a recetangular tank with a unit thickness (2D) and runs well but when I change the mesh to cylinder tank (3D) with all the same conditions for the 2D, I get fatal overflow error!!!
why is this happening? what should I do?
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Old   January 20, 2011, 05:19
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Glenn Horrocks
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Can you describe what you are doing a bit better?

But the problem is probably mesh quality.
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Old   January 20, 2011, 21:38
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I want to model water sloshing in a cylinder tank.
As a first attempt I modeled a rectangular tank with two faces of symetry and the top as open and the other three faces as wall. Defined the mesh displacment for the wall as x=Asinwt. It ran very good.
Now i change the goemetry with a cylindrecal tank and didn't change any settings, but now i get error of "Floating point exception: Overflow".
I have meshed the goemetry in ICEM with an o-grid.
any more details you need?
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Old   January 21, 2011, 01:37
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I now tried a 3D rectangular and agian got the overflow error.
It shouldn't be the quality of the mesh since now I have a complete square hex elements!
Have u got any idea what is going wrong?

regards
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Old   January 21, 2011, 07:28
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No idea what is wrong.

Add the physics into the model one step at a time. Does the 3D model work with a static mesh, but the initial free surface deformed somehow to start a motion? Does the model work with a motion of a small magnitude?
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Old   June 24, 2011, 13:55
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hi,enghamed
I am now modeling a case very similar to your one, the water sloshing in a rectangular tank, I use two domains one as water and the other as air, and applied the displacement sin(wt) to the walls of the tanks. initial condition for air domain volume fraction air= 1& volume fraction water =0. The contrast for water domain. But when I try to solve it, the solver terminate at the 1st timestep, the linear solution for U-mom V-mom and P-vol failed. I change my B.C and timesteps but doesn't help. Do you have any suggestions for my problem. Could you tell me how you set you interface and initial conditions. Very much appreciated.

Regards

Dijun
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Old   June 25, 2011, 06:50
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Do the tutorial free surface flow over a bump for ideas of how to set up and run free surface models.
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Old   June 25, 2011, 13:19
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Thank you . It seems that I define the Buoyancy ref. density as Water's density instead of air's.
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