Hi All,
I need to modify one term of the momentum equation solved in CFDEM. According to set II of Zhou et al. (2010), the viscous term should read:
voidfraction*div(tau)
instead of:
div(voidfraction*tau)
as implemented in cfdemSolverPiso.C.
To do that, I modified cfdemSolverPiso.C as:
======================================================================================
// Momentum predictor
fvVectorMatrix UEqn
(
fvm::ddt(voidfraction,U) - fvm::Sp(fvc::ddt(voidfraction),U)
+ fvm::div(phi,U) - fvm::Sp(fvc::div(phi),U)
// + particleCloud.divVoidfractionTau(U, voidfraction)
+ voidfraction*particleCloud.divVoidfractionTau(U, voidfraction)
==
- fvm::Sp(Ksl/rho,U)
+ fvOptions(U)
);
======================================================================================
and, to remove the voidfraction in tau, the file cfdemCloud.C as:
======================================================================================
tmp cfdemCloud::voidfractionNuEff(volScalarField& voidfraction) const
{
// if (modelType_=="B" || modelType_=="Bfull")
if (modelType_=="A" || modelType_=="B" || modelType_=="Bfull")
{
return tmp
(
#ifdef compre
new volScalarField("viscousTerm", ( turbulence_.mut()
+ turbulence_.mu()
+ turbulenceMultiphase_
)
)
#else
new volScalarField("viscousTerm", ( turbulence_.nut()
+ turbulence_.nu()
+ turbulenceMultiphase_
)
)
#endif
);
}
======================================================================================
The code compiles successfully. However, I don't know whether such changes are formally correct.
Could anyone confirm this?
Best,
Marco