mesh = Grid1D(dx=dx, nx=nx)
from fipy.variables.cellVariable import CellVariable
phase = CellVariable(name='PhaseField', mesh=mesh, value=1.)
from fipy.variables.modularVariable import ModularVariable
theta = ModularVariable(name='Theta', mesh=mesh, value=1.)
theta.setValue(0., where=mesh.getCellCenters()[..., 0] > L / 2.)
from fipy.terms.implicitSourceTerm import ImplicitSourceTerm
mPhiVar = phase - 0.5 + temperature * phase * (1 - phase)
thetaMag = theta.getOld().getGrad().getMag()
implicitSource = mPhiVar * (phase - (mPhiVar < 0))
implicitSource += (2 * s + epsilon**2 * thetaMag) * thetaMag
from fipy.terms.transientTerm import TransientTerm
from fipy.terms.explicitDiffusionTerm import ExplicitDiffusionTerm
phaseEq = TransientTerm(phaseTransientCoeff) == \
ExplicitDiffusionTerm(alpha**2) \
- ImplicitSourceTerm(implicitSource) \
+ (mPhiVar > 0) * mPhiVar * phase
if __name__ == '__main__':
import fipy.viewers
phaseViewer = fipy.viewers.make(vars=phase)
phaseViewer.plot()
dy = L / ny
from fipy.meshes.grid2D import Grid2D
mesh = Grid2D(dx, dy, nx, ny)
from fipy.variables.cellVariable import CellVariable
phase = CellVariable(name = 'PhaseField', mesh = mesh, value = 1.)
from fipy.variables.modularVariable import ModularVariable
theta = ModularVariable(name = 'Theta', mesh = mesh, value = 1.)
x, y = mesh.getCellCenters()[...,0], mesh.getCellCenters()[...,1]
theta.setValue(0., where=(x - L / 2.)**2 + (y - L / 2.)**2 < (L / 4.)**2)
from fipy.terms.implicitSourceTerm import ImplicitSourceTerm
mPhiVar = phase - 0.5 + temperature * phase * (1 - phase)
thetaMag = theta.getOld().getGrad().getMag()
implicitSource = mPhiVar * (phase - (mPhiVar < 0))
implicitSource += (2 * s + epsilon**2 * thetaMag) * thetaMag
from fipy.terms.transientTerm import TransientTerm
from fipy.terms.explicitDiffusionTerm import ExplicitDiffusionTerm
phaseEq = TransientTerm(phaseTransientCoeff) == \
ExplicitDiffusionTerm(alpha**2) \
- ImplicitSourceTerm(implicitSource) \
+ (mPhiVar > 0) * mPhiVar * phase
if __name__ == '__main__':
import fipy.viewers
phaseViewer = fipy.viewers.make(vars = phase)
phaseViewer.plot()
