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-   -   setup vof test problem (https://www.cfd-online.com/Forums/fluent/36944-setup-vof-test-problem.html)

 Fang Jin June 13, 2005 17:39

setup vof test problem

Hi all, I am new to fluent. Just runned a cavity driven flow, it worked, so I want to give multiphase flow a shot, but stucked at vof bc setup.

Here's my testing case, similar as cavity driven, now I have two fluids, one on top of another one, both surrounded by walls. The top wall will move at v1 when starts.

I read the manual, so I know how to setup two phases. What I did is to set "WALL" bc to all walls except the top one which I set it have moving velocity v1.

Ok, now is confusing part. Where shall I specify which mesh belongs to phase 1 and which mesh belongs to phase 2. I read tutorial example of fluent and couple of threads here, figured out "Inlet pressure" will let you setup vof value of one fluid and from what I read, it looks like the bc can be specified for both phases.

So here's my question. In general, how do I specify bc for each phase and how to assign phase to mesh? and maybe how to setup mesh for phase(ex. Gambit)? technically in fluent.

Thanks.

Best Regards

 Fang Jin June 14, 2005 08:27

Re: setup vof test problem

I figured out I should use "patch", but before I iterate, I plot the phase1 or phase2 vof number, it's 0 for phase1 and 1 for phase 2 everywhere. This is not what I want.

First I don't understand why both phase have vof number, I thought it supposed to be a single value which indicate the ratio between them. What I expected is that the vof num is 0 at phase1 and 1 at phase2 initially and they'll change afterwards.

Second I don't understand why only vof number of phase2 can be set initially.

Third fluent doesn't let me define where is phase1 and phase2, the only place I can think of is through "patch", but patch only let me do phase2.

I am using vof model. Really confused. Hope someone help.

Best Regards Fang

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