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-   -   Water droplet, VOF (http://www.cfd-online.com/Forums/fluent/92494-water-droplet-vof.html)

mirabella September 15, 2011 15:09

Water droplet, VOF
 
Hello everybody,

i'm pretty new with Fluent and Multiphase flows. i aim to simulate the interaction between droplet and wall film in a bearing chamber of gas turbine.
i have some problems by defining sharp interfaces for the liquid film and the droplet. i used the sequence Mark/adapt until the message "0 cells for refinement.." appears, but the interface seems to be staggered.
have anyone idea what to do there?

i've another problem by seperating cells into two zones. I get the error message :"Hanging node.."
It would be very kind, when you share here your experience.:)

regards,
Mira

lapin_tout_fou September 16, 2011 11:42

Hi,

For someone who is new in FLUENT, your problem seems really difficult.
Especially the wall film which is not yet possible in FLUENT.
I know developpers are working on it ant that it will probably commercialized in the next version of the software, but today it seems hard to achieve what you're planning, except of course if you realized your own UDF.
For your problem you should contact the support.

m2montazari September 18, 2011 15:33

hi,
I think you can solve this problem but it is somewhat hard! in VOF the interface is sharpest among other models available in fluent. it is said that 3-cell interface is a good interface capturing in VOF. my suggestions are: create a grid that has a very high resolution near the film and the about the locations of the interaction. prefer quadrilateral cells. then reduce timestep to very small size(about 1e-5 sec) and choose a good discritization for parameters(it is probably the hardest step!) and iterate. as the multiphase flows are very sensitive timestep in fluent, I put an emphasise to the timestep size.
I dont know it help or not, but I hope...
yours,
mohammad


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