137 lines
3.4 KiB
C
137 lines
3.4 KiB
C
{
|
|
volScalarField& rDeltaT = trDeltaT();
|
|
|
|
const dictionary& pimpleDict = pimple.dict();
|
|
|
|
scalar maxCo
|
|
(
|
|
pimpleDict.lookupOrDefault<scalar>("maxCo", 0.9)
|
|
);
|
|
|
|
scalar maxAlphaCo
|
|
(
|
|
pimpleDict.lookupOrDefault<scalar>("maxAlphaCo", 0.2)
|
|
);
|
|
|
|
scalar rDeltaTSmoothingCoeff
|
|
(
|
|
pimpleDict.lookupOrDefault<scalar>("rDeltaTSmoothingCoeff", 0.1)
|
|
);
|
|
|
|
label nAlphaSpreadIter
|
|
(
|
|
pimpleDict.lookupOrDefault<label>("nAlphaSpreadIter", 1)
|
|
);
|
|
|
|
scalar alphaSpreadDiff
|
|
(
|
|
pimpleDict.lookupOrDefault<scalar>("alphaSpreadDiff", 0.2)
|
|
);
|
|
|
|
scalar alphaSpreadMax
|
|
(
|
|
pimpleDict.lookupOrDefault<scalar>("alphaSpreadMax", 0.99)
|
|
);
|
|
|
|
scalar alphaSpreadMin
|
|
(
|
|
pimpleDict.lookupOrDefault<scalar>("alphaSpreadMin", 0.01)
|
|
);
|
|
|
|
label nAlphaSweepIter
|
|
(
|
|
pimpleDict.lookupOrDefault<label>("nAlphaSweepIter", 5)
|
|
);
|
|
|
|
scalar rDeltaTDampingCoeff
|
|
(
|
|
pimpleDict.lookupOrDefault<scalar>("rDeltaTDampingCoeff", 1.0)
|
|
);
|
|
|
|
scalar maxDeltaT
|
|
(
|
|
pimpleDict.lookupOrDefault<scalar>("maxDeltaT", GREAT)
|
|
);
|
|
|
|
volScalarField rDeltaT0("rDeltaT0", rDeltaT);
|
|
|
|
// Set the reciprocal time-step from the local Courant number
|
|
rDeltaT.dimensionedInternalField() = max
|
|
(
|
|
1/dimensionedScalar("maxDeltaT", dimTime, maxDeltaT),
|
|
fvc::surfaceSum(mag(rhoPhi))().dimensionedInternalField()
|
|
/((2*maxCo)*mesh.V()*rho.dimensionedInternalField())
|
|
);
|
|
|
|
if (maxAlphaCo < maxCo)
|
|
{
|
|
// Further limit the reciprocal time-step
|
|
// in the vicinity of the interface
|
|
|
|
volScalarField alpha1Bar(fvc::average(alpha1));
|
|
|
|
rDeltaT.dimensionedInternalField() = max
|
|
(
|
|
rDeltaT.dimensionedInternalField(),
|
|
pos(alpha1Bar.dimensionedInternalField() - alphaSpreadMin)
|
|
*pos(alphaSpreadMax - alpha1Bar.dimensionedInternalField())
|
|
*fvc::surfaceSum(mag(phi))().dimensionedInternalField()
|
|
/((2*maxAlphaCo)*mesh.V())
|
|
);
|
|
}
|
|
|
|
// Update tho boundary values of the reciprocal time-step
|
|
rDeltaT.correctBoundaryConditions();
|
|
|
|
Info<< "Flow time scale min/max = "
|
|
<< gMin(1/rDeltaT.internalField())
|
|
<< ", " << gMax(1/rDeltaT.internalField()) << endl;
|
|
|
|
if (rDeltaTSmoothingCoeff < 1.0)
|
|
{
|
|
fvc::smooth(rDeltaT, rDeltaTSmoothingCoeff);
|
|
}
|
|
|
|
if (nAlphaSpreadIter > 0)
|
|
{
|
|
fvc::spread
|
|
(
|
|
rDeltaT,
|
|
alpha1,
|
|
nAlphaSpreadIter,
|
|
alphaSpreadDiff,
|
|
alphaSpreadMax,
|
|
alphaSpreadMin
|
|
);
|
|
}
|
|
|
|
if (nAlphaSweepIter > 0)
|
|
{
|
|
fvc::sweep(rDeltaT, alpha1, nAlphaSweepIter, alphaSpreadDiff);
|
|
}
|
|
|
|
Info<< "Smoothed flow time scale min/max = "
|
|
<< gMin(1/rDeltaT.internalField())
|
|
<< ", " << gMax(1/rDeltaT.internalField()) << endl;
|
|
|
|
// Limit rate of change of time scale
|
|
// - reduce as much as required
|
|
// - only increase at a fraction of old time scale
|
|
if
|
|
(
|
|
rDeltaTDampingCoeff < 1.0
|
|
&& runTime.timeIndex() > runTime.startTimeIndex() + 1
|
|
)
|
|
{
|
|
rDeltaT = max
|
|
(
|
|
rDeltaT,
|
|
(scalar(1.0) - rDeltaTDampingCoeff)*rDeltaT0
|
|
);
|
|
|
|
Info<< "Damped flow time scale min/max = "
|
|
<< gMin(1/rDeltaT.internalField())
|
|
<< ", " << gMax(1/rDeltaT.internalField()) << endl;
|
|
}
|
|
}
|