| Description | I try to repeat the native experiment using OpenFOAM 2.3.0. Solver pimpleFoam is used. The domain has a complex form with one inlet and one outlet. For boundary conditions it was setted values of velocity at inlet and pressure at outlet. The flow is laminar, fluid is newtonian.
According to experimental data the velocity at inlet and pressure at outlet are trancient.
In the simple case, when I fixed the values for them (using fixedValue), I've got a good results (files "statics_*.png).
But when I tried to make the unsteady boundary conditions, at the inlet there are oscillations for pressure, which doesn't correlate with experimental data (files "trancient_*.png").
BC for velocity:
dimensions [0 1 -1 0 0 0 0];
internalField uniform (0 0 0);
boundaryField
{
inlet
{
type uniformFixedValue;
uniformValue tableFile;
tableFileCoeffs
{
fileName "$FOAM_CASE/bc/inlet_velocity.bc"
outOfBounds repeat;
}
}
outlet
{
type zeroGradient;
}
vessel
{
type fixedValue;
value uniform (0 0 0);
}
}
BC for pressure:
dimensions [0 2 -2 0 0 0 0];
internalField uniform 9.421284545;
boundaryField
{
inlet
{
type zeroGradient;
}
outlet
{
type uniformFixedValue;
uniformValue tableFile;
tableFileCoeffs
{
fileName "$FOAM_CASE/bc/outlet_pressure.bc"
outOfBounds repeat;
}
}
vessel
{
type zeroGradient;
}
}
file controlDict:
application pimpleFoam;
startFrom startTime;
startTime 0;
stopAt endTime;
endTime 2;
deltaT 0.001;
writeControl adjustableRunTime;
writeInterval 0.1;
purgeWrite 0;
writeFormat binary;
writePrecision 6;
writeCompression uncompressed;
timeFormat general;
timePrecision 6;
runTimeModifiable true;
adjustTimeStep yes;
maxCo 1;
maxAlphaCo 1;
maxDeltaT 0.1;
file fvSolution:
solvers
{
p
{
solver GAMG;
tolerance 1e-06;
relTol 0.01;
smoother GaussSeidel;
cacheAgglomeration true;
nCellsInCoarsestLevel 10;
agglomerator faceAreaPair;
mergeLevels 1;
}
pFinal
{
solver GAMG;
tolerance 1e-06;
relTol 0;
smoother GaussSeidel;
cacheAgglomeration true;
nCellsInCoarsestLevel 10;
agglomerator faceAreaPair;
mergeLevels 1;
}
"(U|k|epsilon)"
{
solver smoothSolver;
smoother symGaussSeidel;
tolerance 1e-05;
relTol 0.1;
}
"(U|k|epsilon)Final"
{
$U;
tolerance 1e-05;
relTol 0;
}
}
PIMPLE
{
nOuterCorrectors 2;
nCorrectors 4;
nNonOrthogonalCorrectors 5;
pRefCell 0;
pRefValue 0;
}
relaxationFactors
{
fields
{
}
equations
{
"U.*" 1;
"k.*" 1;
"epsilon.*" 1;
}
} |
|---|
