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-   -   Stratified Two-Phase Flow (https://www.cfd-online.com/Forums/openfoam-pre-processing/76248-stratified-two-phase-flow.html)

alberto May 26, 2010 01:15

Sorry, ignore the comment on cavitatingFoam. I was actually referring to interPhaseChangeFoam, which is a VOF code with mass-transfer.

sabin.ceuca May 26, 2010 05:43

Hi guys, I am also working on the simulation of 2-phase stratified flow with OpenFOAM. I would recommend to you “Metro”, that you don’t start the simulation with the full “steam” velocity of 10m/s but using a ramp starting from u_steam = u_water. I have experienced a lot of crashes if not preceding so.
Greatings Sabin

metro May 30, 2010 01:19

Hey

I have been experimenting with the twoPhaseEulerFoam and been applying it to a 10inch pipe with non uniform B.C to determine its accuracy. The conditions were applied with funkySetFields and groovyBC and are piecewise functions for simplicity:rolleyes:. Ive also filled half of the control volume with liquid to help with convergence. The problem which I am encountering is that the system isn't converging and my Courant number exceeds the limits set in the control dict:confused:. Any help will be greatly appreciated.............

(PS Ive already increased the maxdeltaT and changed the U values but no use)

Thanks

Metro

alberto May 30, 2010 02:17

Change one condition at a time to understand what is causing the problem.

You should reduce the maxDeltaT if you have that kind of problem, not increase it :-)

metro May 30, 2010 18:01

Hey Alberto,

I have done the following -

1) decrease the maxdeltaT to 1e-7 (My mistake in the previous thread :rolleyes:)

2) changed the velocities to more realistic figures (1 and 10m/s for liquid and gas)

3) set the internalfield for both the alpha and the velocities (done with funkysetfields and checked in paraView)

4) checked the pressure boundary conditions

And it is still not working, Do you have any ideas? Im stuck and realy need some help. Also does anyone have the details on the interPhaseChangeFoam tutorial and the governing equations?

Thanks

Metro

sabin.ceuca June 4, 2010 08:02

@Metro can you post your input files? Ok, I am not an advanced user of OF but maybe I can help :)
Greats

metro June 11, 2010 01:09

Thanks for the input. I found that I set the phase interfacial properties incorrectly and as a result it affected the convergence. It seems to be working now.

I am currently looking into incorporating a temperature field into the twoPhaseEulerFoam solver. Is there any one who has done this and might be able to assist.

Thanks Metro

sabin.ceuca June 11, 2010 04:58

There are 2 tutorials, take a look at them http://openfoamwiki.net/index.php/Ho...ure_to_icoFoam
and
http://www.cfd-online.com/Forums/ope...interfoam.html

alberto June 11, 2010 14:46

Quote:

Originally Posted by metro (Post 262552)
I am currently looking into incorporating a temperature field into the twoPhaseEulerFoam solver. Is there any one who has done this and might be able to assist.

How do you plan to do this? Meaning, how does your energy equation look like?

Best,
A.

jignesh_thaker2007 January 19, 2012 04:20

hello sir,
 
i m started to solve the problem of two phase pipe flow using interDyMFoam solver in which two liquid water and air flowing inside the pipe.but both have different velocities so how can i take care of the boundary condition at inlet?
at the inlet of the pipe the half portion carries water and another half portion carries air but how can i define B.C.?

please help me.

sabin.ceuca January 19, 2012 06:56

Hi Jignesh,
the solution to your problem is to split your inlet patch in two parts:
one for the air inflow the other for the water inlet. If you don't want to remesh your domain, as required in order to split a patch, you can use swak4Foam or groovyBC (just google for them). They help you to define a BC as an expersion of, in your case, (x,y,z).
Good luck ;)

jignesh_thaker2007 January 21, 2012 01:14

Hii
 
Actually i drew geometry in Gambit and i split inlet in two parts in gambit. then i convert this geometry in openFoam also i put all condition related about that plz check this problem is it right or roungh? so plz give me your mail Id so i will send it to you.

thanks
Jignesh








Quote:

Originally Posted by sabin.ceuca (Post 340083)
Hi Jignesh,
the solution to your problem is to split your inlet patch in two parts:
one for the air inflow the other for the water inlet. If you don't want to remesh your domain, as required in order to split a patch, you can use swak4Foam or groovyBC (just google for them). They help you to define a BC as an expersion of, in your case, (x,y,z).
Good luck ;)



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