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-   -   Is it suitable to use Weller's scheme in this case? (https://www.cfd-online.com/Forums/openfoam/89630-suitable-use-wellers-scheme-case.html)

kaifu June 17, 2011 16:16

Is it suitable to use Weller's scheme in this case?
 
Hi Foamers,

In order to strictly restrict alpha in [0,0.52], I am now considering to use MULES in case of bubbly flow. I have a question here since in Weller's scheme, there is a compression term (eqn 4.13, Rusche). And it is said "The arti ficial term is only active in the thin interface region because of the multiplication term gamma(1-gamma)". It is true in case of liquid-vapor with clear interface which only exists somewhere. However in bubbly flow, the interface could be everywhere. I dont know if it is appropriate to use this scheme in my case. Thanks.

// Kai

santiagomarquezd June 21, 2011 16:56

Quote:

Originally Posted by kaifu (Post 312520)
Hi Foamers,

However in bubbly flow, the interface could be everywhere.

// Kai

Are you considering the bubbles interface as a dispersed interface or tracking each bubble's shape?

Regards.

kaifu June 21, 2011 18:03

Quote:

Originally Posted by santiagomarquezd (Post 312963)
Are you considering the bubbles interface as a dispersed interface or tracking each bubble's shape?

I do not track bubbles interface. As you said, the bubbles interface is treated as a dispersed interface.

santiagomarquezd June 21, 2011 18:08

Hi, MULES and interfaceCompression are intended for VOF problems in which surface is completely described and tracked. Maybe you can explain your case a little bit in order to see if it is possible to use these techniques in your case.

Regards.

kaifu June 22, 2011 05:43

It is a two-phase Euler-Euler case. And I think the the way you define the compression term is different between the interface-tracking and dispersed interface (eqn 3.58 and eqn 4.13, Rusche). In my case, there are two velocity fields: Ua and Ub, instead of the single velocity field in the interface-tracking case.

pbohorquez June 22, 2011 08:09

Just run simple benchmarks to compare with analytic solutions and see what happens. I feel you will be happy with your results.

Quote:

Originally Posted by kaifu (Post 312520)
Hi Foamers,

In order to strictly restrict alpha in [0,0.52], I am now considering to use MULES in case of bubbly flow. I have a question here since in Weller's scheme, there is a compression term (eqn 4.13, Rusche). And it is said "The arti ficial term is only active in the thin interface region because of the multiplication term gamma(1-gamma)". It is true in case of liquid-vapor with clear interface which only exists somewhere. However in bubbly flow, the interface could be everywhere. I dont know if it is appropriate to use this scheme in my case. Thanks.

// Kai



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