startingArray = numerix.zeros(nx, 'd') startingArray[50:90] = 1. var = CellVariable( name = "advection variable", mesh = mesh, value = startingArray) boundaryConditions = ( FixedValue(mesh.getFacesLeft(), valueLeft), FixedValue(mesh.getFacesRight(), valueRight) ) from fipy.terms.transientTerm import TransientTerm from fipy.terms.explicitUpwindConvectionTerm import ExplicitUpwindConvectionTerm eq = TransientTerm() - ExplicitUpwindConvectionTerm(coeff = (velocity,)) if __name__ == '__main__': viewer = fipy.viewers.make(vars=(var,)) for step in range(steps): eq.solve(var, dt = timeStepDuration, boundaryConditions = boundaryConditions, solver = LinearCGSSolver(tolerance = 1.e-15, steps = 2000)) viewer.plot() viewer.plot() raw_input('finished')
def __init__(self, surfactantVar=None, distanceVar=None, bulkVar=None, rateConstant=None, otherVar=None, otherBulkVar=None, otherRateConstant=None, consumptionCoeff=None): """ Create a `AdsorbingSurfactantEquation` object. :Parameters: - `surfactantVar`: The `SurfactantVariable` to be solved for. - `distanceVar`: The `DistanceVariable` that marks the interface. - `bulkVar`: The value of the `surfactantVar` in the bulk. - `rateConstant`: The adsorption rate of the `surfactantVar`. - `otherVar`: Another `SurfactantVariable` with more surface affinity. - `otherBulkVar`: The value of the `otherVar` in the bulk. - `otherRateConstant`: The adsorption rate of the `otherVar`. - `consumptionCoeff`: The rate that the `surfactantVar` is consumed during deposition. """ self.eq = TransientTerm(coeff=1) - ExplicitUpwindConvectionTerm( SurfactantConvectionVariable(distanceVar)) self.dt = Variable(0.) mesh = distanceVar.mesh adsorptionCoeff = self.dt * bulkVar * rateConstant spCoeff = adsorptionCoeff * distanceVar._cellInterfaceFlag scCoeff = adsorptionCoeff * distanceVar.cellInterfaceAreas / mesh.cellVolumes self.eq += ImplicitSourceTerm(spCoeff) - scCoeff if otherVar is not None: otherSpCoeff = self.dt * otherBulkVar * otherRateConstant * distanceVar._cellInterfaceFlag otherScCoeff = -otherVar.interfaceVar * scCoeff self.eq += ImplicitSourceTerm(otherSpCoeff) - otherScCoeff vars = (surfactantVar, otherVar) else: vars = (surfactantVar, ) total = 0 for var in vars: total += var.interfaceVar maxVar = (total > 1) * distanceVar._cellInterfaceFlag val = distanceVar.cellInterfaceAreas / mesh.cellVolumes for var in vars[1:]: val -= distanceVar._cellInterfaceFlag * var spMaxCoeff = 1e20 * maxVar scMaxCoeff = spMaxCoeff * val * (val > 0) self.eq += ImplicitSourceTerm(spMaxCoeff) - scMaxCoeff - 1e-40 if consumptionCoeff is not None: self.eq += ImplicitSourceTerm(consumptionCoeff)