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-   -   VOF - Set up (http://www.cfd-online.com/Forums/fluent/45082-vof-set-up.html)

hungpavn June 19, 2007 02:01

VOF - Set up
 
Dear all!

I start to learn about VOF simulation with the tutorial "Free surface wave simulation using VOF model".

However, I don't want to use UDF. So, could anybody give me some suggestions about setting up VOF without UDF.

I am also confusing about separate two phases, two fluid and initialize.

Many thanks!

anthro June 21, 2007 09:13

Re: VOF - Set up
 
hi,

what are your 2 2 fluids? Is it a heat transfer problem?

rgds, anthro

hungpavn June 29, 2007 04:57

Re: VOF - Set up
 
extually, no!

I use two phases for the wave generation problem without heat or any other.

anthro July 1, 2007 11:40

Re: VOF - Set up
 
hi,

i have the basic general steps for setting up a VOF prob. If u can pass me your email i can send it to you.

rgds anthro

hungpavn July 1, 2007 11:54

Re: VOF - Set up
 
Thanks for helping!

My email is: hungpa_vn@yahoo.com

Rafi July 15, 2007 14:04

Re: VOF - Set up
 
Could you please send me the general setup document for VOF please. Do you also have any advanced document that discusses the discretization setup. If you have any input regarding this matter please let me know.

I am currently running a case : three phase flow but oil and water entering through the liquid inlet. I am having difficulties making the continuity equation drop. Continuity residual fluctuates between 0.1 to 1.9. I am using PISO scheme with body force weighted for pressure, 1st order for momentum and Geo-reconstruct. However, the contour plots indicate reasonable flow distribution so far (.05sec).

I am using a low time step 1e-5. It appears to me that the global courant number kept on going up. Would it help if I decrease the courant number?

Thanks.

Rafiq


garima chaudhary July 19, 2007 04:20

Re: VOF - Set up
 
hi

can u explain me in detail the set up or system i.e.geometry n details of ur problem, might be i can help u after that better

Rafi July 19, 2007 09:41

Re: VOF - Set up
 
Hi Garima, Thanks for your response. I have resolved my problem, which turns out to be related to incorrect use of the non-conformal mesh in FLUENT. I am trying to simulate oil/water/gas sloshing/separation due to wave motion.

Thanks again for your response.

Rafi

Rodi July 27, 2007 02:35

Re: VOF - Set up
 
hi Rafi, I am trying to simulate a gas-liquid flow with the liquid being the primary phase.I have the same problem ,all other Residuals convergence fast except the continuity. I wanna to know what's the meaning of the error use of non-conformal mesh ? How can I avoid that?

Thank you.

Rafi July 27, 2007 11:32

Re: VOF - Set up
 
Hi Rodi, The convergence problem with continuity equation may happen when fluid enters but cannot get out. It can also happen when the quality of the mesh is bad. However, for my case, I used a "Non-conformal interface" option to connect two flow regions that are meshed independently and do not have identical mesh (conformal mesh) on the surface where two volumes are intersecting. For some reason this was not set correctly for my case and I got convergence problem.

For your case, please check the followings:

1. Check the mass balance 2. Check the boundary conditions 3. Check the cell skewness. Hex mesh is preferred for multiphase modeling.

Rafi


monty_p20 May 29, 2011 17:05

vof
 
Hello friends,,


I need your help regarding water droplet simulation through horizontal channel using VOF model. Will you help me please..

Thanks,
Monty


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