Hi all,
There are several differences between CFDEM2.90 and CFDEM2.7.1 that caused significant changes in results of my simulation. The solverPiso codes have some important differences, particularly
in 2.7.1:
fvVectorMatrix UEqn
(
fvm::ddt(voidfraction,U) + fvm::Sp(fvc::ddt(voidfraction),U)
+ fvm::div(phi,U) + fvm::Sp(fvc::div(phi),U)
// + turbulence->divDevReff(U)
+ particleCloud.divVoidfractionTau(U, voidfraction)
==
- fvm::Sp(Ksl/rho,U)
);
While in 2.9.0:
fvVectorMatrix UEqn
(
fvm::ddt(voidfraction,U) - fvm::Sp(fvc::ddt(voidfraction),U)
+ fvm::div(phi,U) - fvm::Sp(fvc::div(phi),U)
// + turbulence->divDevReff(U)
+ particleCloud.divVoidfractionTau(U, voidfraction)
==
- fvm::Sp(Ksl/rho,U)
);
Why the positive (+fvm::) in version 2.7 turned into negative (-fvm::) ?
Could anyone give me a hint on this issue?
Thanks,
Nathan,
xerman | Tue, 11/10/2015 - 17:34
Hi Nathan,
Hi Nathan,
I was wondering the same...have you managed to figure it out?
Xerxes
NTT1508 | Wed, 11/11/2015 - 00:08
Not sure
Hi Xerxes,
My personal understanding is that these codes are optional so you can modify and use flexibly. I have not seen any explanation from the builders yet.
Regards,
hunger | Fri, 11/13/2015 - 15:28
I would also be interested in
I would also be interested in that! Also the cfdemSolverPisoScalar was changed from 2.7.1 to 2.9.0. There the fvm::Sp(...) terms were added to the solver.
ritesh | Fri, 07/15/2016 - 11:39
I would also be interested in
i am still searching...and confused...
NTT1508 | Mon, 07/18/2016 - 01:44
A relation
This might help clarify this problem. But note that it still needs validation for particular cases.
http://cfdem.com/forums/momentum-equation