How could I modify the pEqn.H by adding ajustPhi() in twoPhaseEulerFoam

cheng1988sjtu · April 2, 2013, 11:32

Hi Foamers,

When I use zeroGradient pressure condition at the wall, I could see pressure sigularity at the pReff(), and I searched in the forum, and found that that's due to that fact that there is no adjustPhi after the buoyancy term.

So, I added the following lines before phi = alphaf*phia + betaf*phib;

adjustPhi(phia, Ua, p);
adjustPhi(phib, Ub, p);

however, after I added this lines, I could see that my Dispersed volume fraction is decreasing though slowly.

Could anyone give me a hint on how adjustPhi() should work?

Thanks

Zhen Cheng

cheng1988sjtu · April 2, 2013, 15:36

Never mind, I figured out that the mass reduction is not due to the adjustPhi, and FYI, this approach do eliminate the pressure singularity at the zeroGradient boundary (p).

Charlie

chegdan · April 3, 2013, 11:05

Greetings Zhen Cheng,

Just curious about your findings,

Quote:

Never mind, I figured out that the mass reduction is not due to the adjustPh

What was the source of mass reduction in your simulations? Just in case others run into the same issue.

Dan

Popmech · March 3, 2014, 09:13

Hi, I am using a modified version of the twoPhaseEulerFoam solver to model a mixing vessel with settling particles. I have a zero-gradient pressure condition on all surfaces including the free-surface which is represented by a symmertryPlane type boundary condition. I suffer from a similar problem with a singularity occurring at the pReffCell in the simulation which causes the volume fractions to be solved incorrectly. I have tried implementing the adjustPhi call as described in this thread, though this causes an error stating there is no outflow boundary to adjust. Does someone know how to work around this problem?

Kind Regards, JVZ

April 2, 2013, 11:32	How could I modify the pEqn.H by adding ajustPhi() in twoPhaseEulerFoam	#1
cheng1988sjtu Member Charlie Join Date: Dec 2010 Location: USA Posts: 85 Rep Power: 15	Hi Foamers, When I use zeroGradient pressure condition at the wall, I could see pressure sigularity at the pReff(), and I searched in the forum, and found that that's due to that fact that there is no adjustPhi after the buoyancy term. So, I added the following lines before phi = alphafphia + betafphib; adjustPhi(phia, Ua, p); adjustPhi(phib, Ub, p); however, after I added this lines, I could see that my Dispersed volume fraction is decreasing though slowly. Could anyone give me a hint on how adjustPhi() should work? Thanks Zhen Cheng

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April 2, 2013, 15:36		#2
cheng1988sjtu Member Charlie Join Date: Dec 2010 Location: USA Posts: 85 Rep Power: 15	Never mind, I figured out that the mass reduction is not due to the adjustPhi, and FYI, this approach do eliminate the pressure singularity at the zeroGradient boundary (p). Charlie

March 3, 2014, 09:13		#4
Popmech New Member Josebus van Zyl Join Date: Jan 2013 Location: Stellenbosch Posts: 1 Rep Power: 0	Hi, I am using a modified version of the twoPhaseEulerFoam solver to model a mixing vessel with settling particles. I have a zero-gradient pressure condition on all surfaces including the free-surface which is represented by a symmertryPlane type boundary condition. I suffer from a similar problem with a singularity occurring at the pReffCell in the simulation which causes the volume fractions to be solved incorrectly. I have tried implementing the adjustPhi call as described in this thread, though this causes an error stating there is no outflow boundary to adjust. Does someone know how to work around this problem? Kind Regards, JVZ