// Reinitialize Phasefield with changed interface thickness
private void ReInit(double cahn_old, double cahn)
{
Console.WriteLine($"Reprojecting Phasefield:\n" +
$" old thickness: {cahn_old}\n" +
$" new thickness: {cahn}");
// we assume the current phasefield is close to the equilibrium tangenshyperbolicus form
SinglePhaseField phiNew = new SinglePhaseField(phi.Basis);
GridData GridDat = (GridData)(phi.GridDat);
// compute and project
// step one calculate distance field phiDist = 0.5 * log(Max(1+phi, eps)/Max(1-phi, eps)) * sqrt(2) * Cahn_old
// step two project the new phasefield phiNew = tanh(phiDist/(sqrt(2) * Cahn_new))
// here done in one step, with default quadscheme
// ===================
phiNew.ProjectField(
(ScalarFunctionEx) delegate(int j0, int Len, NodeSet NS, MultidimensionalArray result)
{ // ScalarFunction2
Debug.Assert(result.Dimension == 2);
Debug.Assert(Len == result.GetLength(0));
int K = result.GetLength(1); // number of nodes
// evaluate Phi
// -----------------------------
phi.Evaluate(j0, Len, NS, result);
// compute the pointwise values of the new level set
// -----------------------------
result.ApplyAll(x => Math.Tanh(0.5 * Math.Log(Math.Max(1 + x, 1e-10) / Math.Max(1 - x, 1e-10)) * (cahn_old / cahn)));
}
);
phi.Clear();
phi.Acc(1.0, phiNew);
CorrectionLevSet.Clear();
CorrectionLevSet.Acc(1.0, phi);
this.CorrectionLsTrk.UpdateTracker(0.0);
// update DG LevelSet
DGLevSet.Clear();
DGLevSet.Acc(1.0, phi);
reinit++;
PlotCurrentState(0.0, reinit);
}
protected override double RunSolverOneStep(int _TimestepNo, double _dt, double _phystime)
{
using (new FuncTrace())
{
if (_TimestepNo == -1.0)
{
Console.WriteLine("Initializing Phasefield");
}
else
{
Console.WriteLine("Moving Phasefield in timestep #{0}, t = {1}, dt = {2} ...", _TimestepNo, _phystime, _dt);
}
// Perform timestep
// ================
if (this.Control.CurvatureCorrectionType == PhasefieldControl.CurvatureCorrection.DirectCoupledOnce)
{
phi0.Clear();
phi0.Acc(1.0, phi);
gradPhi0.Clear();
gradPhi0.Gradient(1.0, phi0);
VectorField <SinglePhaseField> filtgrad;
CurvatureAlgorithmsForLevelSet.CurvatureDriver(
CurvatureAlgorithmsForLevelSet.SurfaceStressTensor_IsotropicMode.Curvature_Projected,
CurvatureAlgorithmsForLevelSet.FilterConfiguration.Phasefield,
this.DCurvature, out filtgrad, CorrectionLsTrk,
this.DCurvature.Basis.Degree * 2,
phi0);
}
//PlotCurrentState(_phystime, new Foundation.IO.TimestepNumber(new int[] { _TimestepNo , 0}), 2);
base.Timestepping.Solve(_phystime, _dt);
//PlotCurrentState(_phystime, new Foundation.IO.TimestepNumber(new int[] { _TimestepNo }), 2);
// algebraic correction
switch (this.Control.CorrectionType)
{
case PhasefieldControl.Correction.Concentration:
ConservativityCorrection();
break;
case PhasefieldControl.Correction.Mass:
MassCorrection();
break;
case PhasefieldControl.Correction.None:
default:
break;
}
// update DG LevelSet
DGLevSet.Clear();
DGLevSet.Acc(1.0, phi);
CorrectionLevSet.Clear();
CorrectionLevSet.Acc(1.0, phi);
this.CorrectionLsTrk.UpdateTracker(0.0);
// return
// ======
WriteLogLine(_TimestepNo, _phystime + _dt);
//PlotCurrentState(_phystime, new Foundation.IO.TimestepNumber(new int[] { _TimestepNo }), 2);
Console.WriteLine("done moving Phasefield in timestep #{0}.", _TimestepNo);
return(_dt);
}
}