| anhkenyt |
September 9, 2020 18:55 |
The convergence problem of IcoFoam with cyclic boundary
1 Attachment(s)
Hi all,
I run cavity case with cyclic boundary which applies in two sides (the top still moves with constants velocity ) with icoFoam.Of course, I want a solution of U, p as good as impossible.
When I check the residual of the solver, I realize residual of p very higher than the case without cyclic boundary(~1)
What I don't understand is:
1. When checking the convergence of solver, we just care initialResidual ? that correct?
2. If my opinion is correct, how to decrease the residual of p in my case (To get a correct solution)?. If not, can you give me some suggestions to solve my problem?
This is fvSolution file of mine
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 3.0.1 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "system";
object fvSolution;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
solvers
{
p
{
solver PCG;
preconditioner DIC;
tolerance 1e-06;
relTol 0.05;
}
pFinal
{
$p;
relTol 0;
}
U
{
solver smoothSolver;
smoother symGaussSeidel;
tolerance 1e-05;
relTol 0;
}
}
PISO
{
nCorrectors 2;
nNonOrthogonalCorrectors 0;
pRefCell 0;
pRefValue 0;
}
PIMPLE
{
nOuterCorrectors 1;
nCorrectors 2;
nNonOrthogonalCorrectors 2;
pRefCell 0;
pRefValue 0;
}
And 0/U and 0/p
Code:
/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 6
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volVectorField;
object U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [0 1 -1 0 0 0 0];
internalField uniform (0 0 0);
boundaryField
{
movingWall
{
type fixedValue;
value uniform (1 0 0);
}
inlet
{
type cyclic;
// value uniform (0.001 0 0);
}
outlet
{
//type zeroGradient;
type cyclic ;
};
fixedWalls
{
type noSlip;
}
frontAndBack
{
type empty;
}
}
// ************************************************************************* //
Code:
/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 6
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
object p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [0 2 -2 0 0 0 0];
internalField uniform 0;
boundaryField
{
movingWall
{
type zeroGradient;
}
inlet
{
type cyclic;
// value uniform (0.001 0 0);
}
outlet
{
//type zeroGradient;
type cyclic ;
}
fixedWalls
{
type zeroGradient;
}
frontAndBack
{
type empty;
}
}
// ************************************************************************* //
Please find in the attachment the residual results for the simulation.
I will be happy to get your feedback.
Regard! |
