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 duongquaphim May 27, 2009 07:52

Diffuse Interface Method in interFOAM

Hello,

I am a new guy with OF and I am working in multiphase flow. As I knew, in order to physically describe the interface, a new method called Diffuse Interface Method is introduced. Does any one know whether is is implemented in OF 1.5?

Thanks,

Anh Duong

 4xF June 12, 2009 10:17

The diffuse interface method assumes that the interface is described by the spatial variation of a variable. In the VOF method, this is the scalar representing the limit between two fluids. In level set methods, this is the level function itself. Typically, the variations of the variable are noticeable only in the vicinity of the interface, which is usually spread over 2 to 3 control volumes.

From there, the diffuse interface methods states that the forces acting at the liquid/gas interface such as surface tension are represented by volumetric forces which are everywhere zero but at the interface. Since the interface representation is spread over 2 or 3 control volumes, so is the volumetric force. The usual jump condition at the interface ( sigma*curvature for pressure) is thus smeared over the interface representation. In the diffuse interface model, this jump condition is recovered by integrating the volumetric force along the interface normal. Should the interface thickness tend to zero, the jump condition is then recovered.

So, in conclusion, if you look at the InterFoam solver, it implements the diffuse interface model...

Hope this helps...

 duongquaphim June 26, 2009 05:16

Hi Frank,

Thank you for your answer. As you mention, I checked the InterFoam solver and gammaEqn.H. However, in this solver, they only solve a convective equation of gamma and I did not find anything relating to Diffuse Interface method.

Is it true that you were mentioning about compressive gamma coefficient? I think these two methods are different.