MULES in interPhaseChangeFoam
 

Hello everybody

In gammaEqn.H of interPhaseChangeFoam solver we have these lines:


volScalarField Sp
(
IOobject
(
"Sp",
runTime.timeName(),
mesh
),
vDotvAlphal - vDotcAlphal
);
volScalarField Su
(
IOobject
(
"Su",
runTime.timeName(),
mesh
),
divU*gamma
+ vDotcAlphal
);


MULES::implicitSolve(oneField(), gamma, phi, phiGamma, Sp, Su, 1, 0);


why isn't Sp zero, if the equation to solve (MULESTemplates.C) is this:

d(1*psi)/dt + div(phigamma) + Sp*gamma - Su = 0

Is Sp different from zero to improve convergence? Or what?