56bfc75949
"pos" now returns 1 if the argument is greater than 0, otherwise it returns 0. This is consistent with the common mathematical definition of the "pos" function: https://en.wikipedia.org/wiki/Sign_(mathematics) However the previous implementation in which 1 was also returned for a 0 argument is useful in many situations so the "pos0" has been added which returns 1 if the argument is greater or equal to 0. Additionally the "neg0" has been added which returns 1 if if the argument is less than or equal to 0.
137 lines
3.2 KiB
C
137 lines
3.2 KiB
C
{
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volScalarField& rDeltaT = trDeltaT.ref();
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const dictionary& pimpleDict = pimple.dict();
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scalar maxCo
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(
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pimpleDict.lookupOrDefault<scalar>("maxCo", 0.9)
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);
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scalar maxAlphaCo
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(
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pimpleDict.lookupOrDefault<scalar>("maxAlphaCo", 0.2)
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);
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scalar rDeltaTSmoothingCoeff
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(
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pimpleDict.lookupOrDefault<scalar>("rDeltaTSmoothingCoeff", 0.1)
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);
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label nAlphaSpreadIter
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(
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pimpleDict.lookupOrDefault<label>("nAlphaSpreadIter", 1)
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);
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scalar alphaSpreadDiff
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(
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pimpleDict.lookupOrDefault<scalar>("alphaSpreadDiff", 0.2)
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);
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scalar alphaSpreadMax
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(
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pimpleDict.lookupOrDefault<scalar>("alphaSpreadMax", 0.99)
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);
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scalar alphaSpreadMin
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(
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pimpleDict.lookupOrDefault<scalar>("alphaSpreadMin", 0.01)
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);
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label nAlphaSweepIter
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(
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pimpleDict.lookupOrDefault<label>("nAlphaSweepIter", 5)
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);
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scalar rDeltaTDampingCoeff
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(
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pimpleDict.lookupOrDefault<scalar>("rDeltaTDampingCoeff", 1.0)
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);
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scalar maxDeltaT
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(
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pimpleDict.lookupOrDefault<scalar>("maxDeltaT", GREAT)
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);
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volScalarField rDeltaT0("rDeltaT0", rDeltaT);
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// Set the reciprocal time-step from the local Courant number
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rDeltaT.ref() = max
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(
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1/dimensionedScalar("maxDeltaT", dimTime, maxDeltaT),
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fvc::surfaceSum(mag(rhoPhi))()()
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/((2*maxCo)*mesh.V()*rho())
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);
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if (maxAlphaCo < maxCo)
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{
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// Further limit the reciprocal time-step
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// in the vicinity of the interface
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volScalarField alpha1Bar(fvc::average(alpha1));
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rDeltaT.ref() = max
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(
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rDeltaT(),
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pos0(alpha1Bar() - alphaSpreadMin)
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*pos0(alphaSpreadMax - alpha1Bar())
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*fvc::surfaceSum(mag(phi))()()
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/((2*maxAlphaCo)*mesh.V())
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);
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}
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// Update tho boundary values of the reciprocal time-step
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rDeltaT.correctBoundaryConditions();
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Info<< "Flow time scale min/max = "
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<< gMin(1/rDeltaT.primitiveField())
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<< ", " << gMax(1/rDeltaT.primitiveField()) << endl;
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if (rDeltaTSmoothingCoeff < 1.0)
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{
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fvc::smooth(rDeltaT, rDeltaTSmoothingCoeff);
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}
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if (nAlphaSpreadIter > 0)
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{
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fvc::spread
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(
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rDeltaT,
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alpha1,
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nAlphaSpreadIter,
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alphaSpreadDiff,
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alphaSpreadMax,
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alphaSpreadMin
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);
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}
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if (nAlphaSweepIter > 0)
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{
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fvc::sweep(rDeltaT, alpha1, nAlphaSweepIter, alphaSpreadDiff);
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}
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Info<< "Smoothed flow time scale min/max = "
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<< gMin(1/rDeltaT.primitiveField())
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<< ", " << gMax(1/rDeltaT.primitiveField()) << endl;
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// Limit rate of change of time scale
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// - reduce as much as required
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// - only increase at a fraction of old time scale
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if
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(
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rDeltaTDampingCoeff < 1.0
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&& runTime.timeIndex() > runTime.startTimeIndex() + 1
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)
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{
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rDeltaT = max
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(
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rDeltaT,
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(scalar(1.0) - rDeltaTDampingCoeff)*rDeltaT0
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);
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Info<< "Damped flow time scale min/max = "
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<< gMin(1/rDeltaT.primitiveField())
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<< ", " << gMax(1/rDeltaT.primitiveField()) << endl;
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}
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}
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