mechy |
September 20, 2013 17:40 |
how I can increase the accuracy of flow pressure ?
i all
I have simulated flow around a cylinder by OF and FLUENT
In both software, I use a high quality and fine structure mesh which lead to y+<5 over walls and use Kw-sst model
also the setting for OF and FLUENT is as follow
FLUENT BCs:
inlet ========> velocity inlet U=7m/sec k=.2 omega=170
outlet=======> pressure outlet
FLUENT settigs
solver =============> PISO
residual=1e-5
In OF I have used pimpleFoam and setting are as follow
any help will be appreciated
Code:
object k;
dimensions [ 0 2 -2 0 0 0 0 ];
internalField uniform 0.2;
boundaryField
{
outlet
{
type zeroGradient;
}
inlet
{
type fixedValue;
value uniform .2;
}
circle
{
type kLowReWallFunction;
value uniform 1e-6;
}
frontAndBackPlanes
{
type empty;
}
Code:
object omega;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [ 0 0 -1 0 0 0 0 ];
internalField uniform 170;
boundaryField
{
outlet
{
type zeroGradient;
}
inlet
{
type fixedValue;
value uniform 170;
}
circle
{
type omegaWallFunction;
value uniform 1e-6;
}
Code:
object U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [ 0 1 -1 0 0 0 0 ];
internalField uniform ( 0 0 0 );
boundaryField
{
}
circle
{
type fixedValue;
value uniform ( 0 0 0 );
}
wall
{
type fixedValue;
value uniform ( 0 0 0 );
}
inlet
{
type fixedValue;
value uniform ( 7. 0 0 );
}
outlet
{
type zeroGradient;
Code:
object nut;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [ 0 2 -1 0 0 0 0 ];
internalField uniform 0;
boundaryField
{
wallup
{
type nutUSpaldingWallFunction;
value uniform 0;
}
wallp
{
type nutUSpaldingWallFunction;
value uniform 0;
}
outlet
{
type calculated;
value uniform 0;
}
inlet
{
type calculated;
value uniform 0;
}
circle
{
type nutUSpaldingWallFunction;
value uniform 0;
}
Code:
object fvSchemes;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
ddtSchemes
{
default Euler;
}
gradSchemes
{
default Gauss linear ;
}
divSchemes
{
default none;
div(phi,U) Gauss limitedLinearV 1;
div(phi,k) Gauss limitedLinear 1;//
div(phi,omega) Gauss limitedLinear 1;//
div((nuEff*dev(T(grad(U))))) Gauss linear;
div((nuEff*dev(grad(U).T()))) Gauss linear;
}
laplacianSchemes
{
default Gauss linear corrected;
}
interpolationSchemes
{
default linear;
}
snGradSchemes
{
default corrected;
}
fluxRequired
{
default no;
// pcorr ;
p;
}
Code:
solvers
{
p
{
solver GAMG;
tolerance 1e-5;
relTol 0;
smoother GaussSeidel;
nPreSweeps 1;
nPostSweeps 2;
cacheAgglomeration true;
directSolveCoarsest true;
agglomerator faceAreaPair;
nCellsInCoarsestLevel 100;
mergeLevels 1;
minIter 1;
}
pFinal
{
solver GAMG;
tolerance 1e-9;
relTol 0;
smoother GaussSeidel;
nPreSweeps 1;
nPostSweeps 2;
cacheAgglomeration true;
agglomerator faceAreaPair;
nCellsInCoarsestLevel 100;
mergeLevels 1;
minIter 1;
}
"(U|k|omega)"
{
solver smoothSolver;
smoother GaussSeidel;
tolerance 1e-5;
relTol 0;
nSweeps 1;
minIter 1;
}
"(UFinal|kFinal|omegaFinal)"
{
solver smoothSolver;
smoother GaussSeidel;
tolerance 1e-6;
relTol 0.0;
nSweeps 1;
minIter 1;
}
}
PIMPLE
{
nOuterCorrectors 4;
nCorrectors 2;
nNonOrthogonalCorrectors 3;
pRefCell 0;
pRefValue 0;
correctPhi no;
// momentumPredictor yes;
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