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Enclose equation in simplefoamget another result

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Old   March 9, 2009, 06:08
Default Hi OpenFoam experts, is it
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Hi OpenFoam experts,

is it a difference for openFoam or get another results, if for example I write in simpleFoam-case solver
...
tmp<fvvectormatrix> UEqn
(
fvm::div(phi, U)
+ turbulence->divR(U)
+ fvc::grad(p)
);

UEqn().relax();
solve(UEqn() == 0);// change
...

instead of
...
tmp<fvvectormatrix> UEqn
(
fvm::div(phi, U)
+ turbulence->divR(U)
);

UEqn().relax();

solve(UEqn() == -fvc::grad(p));
...

I suppose i get another result, if i view the flows in paraFoam.

Regards,
Khaled
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Old   March 9, 2009, 06:15
Default Actually what you have done he
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Gavin Tabor
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Actually what you have done here is to change the SIMPLE algorithm very fundamentally. SIMPLE (and PISO) split the discretisation of the momentum equation into pressure and everything else; what you have done is to lump them all in together.

Gavin
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Old   March 9, 2009, 06:26
Default Hi Gavin, that is it is a d
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Hi Gavin,

that is it is a disadvantage with regards to the convergence?

Regards,
Khaled
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