Momentum equation of interFoam?
 

Dear Foamer,
I am a beginner in interFoam of OpenFoam. I wonder if there are someone could show me how the momentum equation of interFoam in version 1.6.x is demonstrated below:

ddt(rho,U) + div(rhophi,U) = grad(P) + rho*g + fv + laplace(mueff,U)

inwhich:
fv : surface tension force
rho = alpha1*rho1+(1-alpha1)*rho2
U = alpha1*U1+(1-alpha1)*U
rhophi = rho*U + alpha1*(1-alpha1)*(rho1-rho2)*(U1-U2)

I tried from two equations of each phase, but I am not successful.

Thanks a lot.

Milou

Check the internet for Ruschke's Ph. D. Thesis!

In this forum is this thesis serveral times mentioned, just keep looking at it.

If ya can't find it, send me aderess to where I can send it!

Cheers

************
http://powerlab.fsb.hr/ped/kturbo/OpenFOAM/docs/HenrikRuschePhD2002.pdf
***************

Thanks for your quick reply.
In fact, I had read Rusche's PhD thesis several times but if I wouldn't make a mistakes and what I understand is that the chapter 3: Two Fluid Methodology describes the averaged equation for each phase and the model for the last term in the averaged momentum equation; and the chapter 4: Interface capturing Methodology talks about the mometum equation for a domaine with an interface by using the indicator gamma or alpha1.
By looking all two chapters, I could not find some things similar to:
ddt(rho,U)+div(rhophi,U)=....
and how can we explain that:
rhophi = rho*U + alpha1*(1-alpha1)*(rho1-rho2)*(U1-U2)

Thanks for your answer.

Milou

Properly you have already found it:

http://www.cfd-online.com/Forums/ope...of-method.html

In this blog there is a hot discussion on going.

Cheers,

Dear Claus Meister,
Thanks for your indication on VOF method blog. I will go to these comments on the blog immediately.
Best regards

Dear Claus,
I read the blog of VOF method, really, there are many comment on VOF method, especially on the gamma equation, on interface properties base on gamme discusion, on MULES...
And I found that there are the thesis of Patricio Bohorquez is very interesting, especially the definition of "mass velocity" and "volumetric velocity". But I could not find out my question there.
Thanks for your patient support.
Best regards.
Milou

see equation 4.24 in Rusche's thesis. That's the form of the momentum equation closest to the code as far as I could find.

Hi idrama,
Would yo please send me the PDF file of this thesis, I cannot access to it.
Thanks

you can also check this journal:
http://pre.aps.org/abstract/PRE/v79/i3/e036306

Hi,

Regarding to the equation(20) of I have checked interFoam UEqn.H. Two following terms are missing:

While they are included in porousInterFoam. Anyone knows the reason?

Regards,

Elham