[Mdong]

Hi,everyone
According to the sign of div(U), I want to choose different viscosity coefficients(mu) in rhoCentralFoan. But I compiled it and found that the judgment didn't work.Please give me some advice.
Thanks

This is my way:add volScalarField divU and D in createFields.H,then use divU and D in rhoCentralFoam.C
//add div(U)

volScalarField divU
(
IOobject
(
"divU",
runTime.timeName(),
mesh,
IOobject::NO_READ,
IOobject::AUTO_WRITE
),
fvc::div(U)
);

volScalarField D
(
IOobject
(
"D",
runTime.timeName(),
mesh
),
mesh,
dimensionedScalar("D", dimless, 1.0)
);

//
//Judge the divergence of velocity

forAll(divU,totCells)
{
if(divU[totCells] < 0.0)
{
D[totCells]= 1;
}
else
{
D[totCells]= 2;
}
}

//chose diffirent muEff
volScalarField muEff("muEff", D*turbulence->muEff());
volTensorField tauMC("tauMC", muEff*dev2(Foam::T(fvc::grad(U))));