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-   -   Steady state in VOF (http://www.cfd-online.com/Forums/fluent/30679-steady-state-vof.html)

CFD Newbie December 14, 2002 22:50

Steady state in VOF
 
I have been running VOF simulations in fluent 6. The problem is prety simple, a drop of liquid falling over a sphere at very small velocities. Air is flowing around at velocities 50% higher. Some simulations have reached 12 real seconds but the streamline function lines keep on changing.

May I expect to reach to steady state?

Thnx for any idea.

CFD Newbie

MissNancy December 15, 2002 00:20

Re: Steady state in VOF
 
Have you started with unsteady state conditions? The liquid drop is falling from the top on a sphere (EXACTLY from the top?)? Are you modeling the liquid film on a sphere by VOF? From which direction the air is flowing?

Nancy

CFD Newbie December 16, 2002 01:27

Re: Steady state in VOF
 
I have started with a seemingly realistic shape ( but still unsteady) of the fluid, expecting the shape of the film as part of the solution.

The liquid drop falls exactly from the top.

Yes, I'm modeling the liquid film on the sphere by VOF and the air is flowing concurrently downward.

Thanks for your answer.

Yours truly

CFD Newbie

CFD MAN December 16, 2002 01:41

Re: Steady state in VOF
 
Whats the film thickness you are expecting? Whats the weber/capillary number?

CFD MAN

CFD Newbie December 18, 2002 17:11

Re: Steady state in VOF
 
The Weber number I'm using are of the order of 10-3 to 10-4, calculated by We=viscosity*velocity/surface tension

I don't know how to estimate the film thickness, can you please provide me some information?

thnx

CFD Newbie


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