# twoPhaseEulerFoam - Help needed

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November 2, 2012, 22:47
#2
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Dongyue Li
Join Date: Jun 2012
Location: Torino, Italy
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Quote:
 Originally Posted by Mineral 1. In trasportProperties what does the d mean? Accoring to the bubbleFoam wiki, it is a phase diameter, but what does that mean in practice? Some sort of artificial particle diameter?
as far as I know, the da and db is the diameters of the two phases. if phasea is a air bubble , the da is the average bubble diameter. if the phaseb is water, think about this: if the air was injected high flow rate.the water would create a water droplet, so the db is the diameter of the droplet.

Quote:
 Originally Posted by Mineral 3. Does anyone have a paper on the k-epsilon turbulance model? The parameters implemented in my case folder are just some values taken from the tutorials, and actually that might be the problem with my simulation altough my money is on the BC's.
in the tutorial, u can find the turbulance is off, Prof.alberto said the turbulance model in this solver is not perfect.
http://www.cfd-online.com/Forums/ope...eulerfoam.html

thats what I konw, correct me if i was wrong.

 November 7, 2012, 09:37 #3 New Member   T.B Join Date: Oct 2012 Location: Norway Posts: 8 Rep Power: 6 Thank you Forrest for your input, I have now found the solution to my problem and it was the scaling of the model. I checked the points file and the domain was from (0 0 0) to (50 50 100) but using transformPoints -scaling '(0.001 0.001 0.001)' did the trick! I also found some handy info about k-epsilon here on cfd-online http://www.cfd-online.com/Wiki/Standard_k-epsilon_model To bad though that the model is not good in twoPhaseEulerFoam Also I found somwhere that alphaalpha is not used in the solver. I have a question now tough, has anyone knowledge or experience how to implement a BC where a boundary acts as an outlet for phase A, and a wall for phase B? In someway like a filter? Or some other option to make part of the boundary absorb the dispersed phase. Last edited by Mineral; November 7, 2012 at 10:21.

 November 7, 2012, 20:11 #4 Senior Member   Dongyue Li Join Date: Jun 2012 Location: Torino, Italy Posts: 754 Rep Power: 10 Thank you for that informtion. type: inletOulet would be suited for you. more details you could check it out in the user guide. Best,

 November 11, 2012, 21:40 #5 New Member   T.B Join Date: Oct 2012 Location: Norway Posts: 8 Rep Power: 6 I have now tried many different methods and lots of google searches, but still no success. inletOutlet does not do the trick although it sounds logical to me.

November 11, 2012, 21:50
#6
Senior Member

Dongyue Li
Join Date: Jun 2012
Location: Torino, Italy
Posts: 754
Rep Power: 10
Quote:
 Originally Posted by Mineral I have now tried many different methods and lots of google searches, but still no success. inletOutlet does not do the trick although it sounds logical to me.

November 12, 2012, 02:36
#7
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T.B
Join Date: Oct 2012
Location: Norway
Posts: 8
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Quote:
Yes, please have a look at this, this is a simple 2D test case with coarse mesh.
The inflow is air-water mixture with 1% water, flowing through a channel with two wall where their front faces are supposed to absorb the water. The BCs in the attached case are just simple zero velocity on all wall faces, but I have been playing around with the BC on the two faces which I want to absorb the water, called "filter" in the boundary list.

Cheers, hope you will have time to have a look at this.
Attached Files
 filterTestCase.tar.gz (24.7 KB, 23 views)

 Tags netgen, twophaseeulerfoam

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