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-   -   VOF analysis help needed... (http://www.cfd-online.com/Forums/fluent/31132-vof-analysis-help-needed.html)

Leo March 22, 2003 10:46

VOF analysis help needed...
 
Hi everybody

I am trying to model a free surface flow. I have a closed cavity(3D), with a pipe in it. The pipe rests in a liquid, and the liquid level is known ( half of the cavity is full of liquid) the pipe is rotating with a certain rpm and the rise of the liquid is expected in the pipe.

So at first I tried to model the problem in 2 D , with axis symmetric swirl. The grid is structural and fine I choose VOF with geo-reconstruct with implicit body force treatment on. Defined a swirl velocity using the rotat. speed and the geometry (rad. cood X w) and patched the region in the pipe with it. Also patched the initial liquid level. Unsteady analysis implicit, 1st order, with standard k-e model. Body force discr. for pressure, PISO pres-vel coupling, with skewness and neighbour correction on. All under-rel params are 1. The time step is 1e-5, and I tried many configurations but could not reach a physical solution..(that is a capillary rise on the wall of the pipe ?) Chose engine oil as the liq and air as the gas phase. I tried surface tension, wall adhesion etc. But still could not get a solution So any comments? any suggestions will be very helpful. Regards

Leo Lay

of the pi

newbie March 24, 2003 15:23

Re: VOF analysis help needed...
 
Did you defined the operation pressure in a point where you know there is no fluid? Also try a not so heavy liquid.

Regards

newbie

anna March 25, 2003 17:13

Re: VOF analysis help needed...
 
what is happening with gravitation, is it defined/enabled, in patricular direction/axes

anna

Leo March 26, 2003 03:07

Re: VOF analysis help needed...
 
I both defined the operation density and the gravity (-y direction with a magnitude of 9.81) but still no solution.. Leo

prasanth March 28, 2003 06:31

Re: VOF analysis help needed...
 
hi Leo, My problem is also almost similar. but in my problem, there is cryogenic liquid in the closed enclosure and is partially filled. I have to study the effect due to the aplication of heat flux on the walls. when using geo-reconstruct, liquid is gettiing into vapor zone as disperse. so i started giving g value from 0 and increased to 9.81 in steps. now the problem is how to incorporate evaporation at the interface. if any body knows please help me prasanth


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