[AliE]

Dear all,

I have a question on SIMPLEC in openFOAM. Inspecting the source file I can find the following lines in pEqn.H:

if (simple.consistent())
{
rAtU = 1.0/(1.0/rAU - UEqn.H1()); // ok (rAtU=1/(aP-sum(a_nb)))
phiHbyA +=
fvc::interpolate(rAtU() - rAU)*fvc::snGrad(p)*mesh.magSf(); // Ok, this defines pressure-correction coeffs later.

HbyA -= (rAU - rAtU())*fvc::grad(p); // Why doing that ?
}

The line that creates me some troubles is the last one. It seems that before solving the pressure equation, it corrects the HbyA (which is sum(a_nb)/aP*U_nb, right? ) by a quantity depending on the previous iteration pressure field.

Up to my Knowledge, this is not included in the original paper of Van Doormal and Raithby.

I naturally not saying that it is wrong, but I am curious to know the theoretical motivation behind this correction. Any Hint?

Thank you very much!

[massive_turbulence]

Originally Posted by AliE

Dear all,

I have a question on SIMPLEC in openFOAM. Inspecting the source file I can find the following lines in pEqn.H:

if (simple.consistent())
{
rAtU = 1.0/(1.0/rAU - UEqn.H1()); // ok (rAtU=1/(aP-sum(a_nb)))
phiHbyA +=
fvc::interpolate(rAtU() - rAU)*fvc::snGrad(p)*mesh.magSf(); // Ok, this defines pressure-correction coeffs later.

HbyA -= (rAU - rAtU())*fvc::grad(p); // Why doing that ?
}

The line that creates me some troubles is the last one. It seems that before solving the pressure equation, it corrects the HbyA (which is sum(a_nb)/aP*U_nb, right? ) by a quantity depending on the previous iteration pressure field.

Up to my Knowledge, this is not included in the original paper of Van Doormal and Raithby.

I naturally not saying that it is wrong, but I am curious to know the theoretical motivation behind this correction. Any Hint?

Thank you very much!

Yeah it's puzzling, but proofs are satisfying once understood. I myself will just leave a note here with this link and have look under 2.2.2 Simplec.

http://openfoamwiki.net/index.php/SimpleFoam

Best regards!