Implementation of advection in alphaEqn.H in settlingFoam

Navip · July 17, 2015, 00:34

Dear Foamers,

I wish to add an advection term (div(U*Alpha)) in the settlingFoam solver, alphaEqn.H.

I try different option but no one works. Does anyone of you have an idea how to do that ? The problem lies on the fact that U and Alpha are matrix I think.

volScalarField divU(fvc::div(phi/fvc::interpolate(rho)));

fvScalarMatrix AlphaEqn
(
fvm::ddt(rho, Alpha)
+ fvm::div(phiAlpha, Alpha)
+ fvm::div(divU,Alpha) //I tried this as divU is showned just up
- fvm::laplacian(mut, Alpha)
);

Help would be appreciate,

Xavier

rapierrz · July 17, 2015, 02:09

Hi Xavier,

I have the same problem with a small difference.when I use

phi/fvc::interpolate(rho), result of alpha become with high gradients in some

locations and I don't know the reason.

But in your case i think if your solver even make succesfully it has dimentional

problem in divU.

July 17, 2015, 00:34	Implementation of advection in alphaEqn.H in settlingFoam	#1
Navip New Member Xavier Pivan Join Date: May 2015 Posts: 10 Rep Power: 10	Dear Foamers, I wish to add an advection term (div(UAlpha)) in the settlingFoam solver, alphaEqn.H. I try different option but no one works. Does anyone of you have an idea how to do that ? The problem lies on the fact that U and Alpha are matrix I think. volScalarField divU(fvc::div(phi/fvc::interpolate(rho))); fvScalarMatrix AlphaEqn ( fvm::ddt(rho, Alpha) + fvm::div(phiAlpha, Alpha) + fvm::div(divU,Alpha) //I tried this as divU is showned just up* - fvm::laplacian(mut, Alpha) ); Help would be appreciate, Xavier

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July 17, 2015, 02:09		#2
rapierrz Senior Member Hesam Join Date: Feb 2015 Posts: 139 Rep Power: 11	Hi Xavier, I have the same problem with a small difference.when I use phi/fvc::interpolate(rho), result of alpha become with high gradients in some locations and I don't know the reason. But in your case i think if your solver even make succesfully it has dimentional problem in divU.