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Hier finden Sie wissenschaftliche Publikationen aus den FraunhoferInstituten. A fast immersed interface method for the CahnHilliard equation with arbitrary boundary conditions in complex domains
 Computational materials science 140 (2017), pp.2231 ISSN: 09270256 

 English 
 Journal Article 
 Fraunhofer ITWM () 
 immersed interface method; CahnHilliard equation; surface wetting; fourier integration 
Abstract
A fast immersed boundary method for the CahnHilliard equation is introduced. The decomposition of the fourthorder nonlinear CahnHilliard equation into a system of linear parabolic secondorder equations allows to pose arbitrary Neumann or surface wetting conditions on the boundary. In space a finitevolume discretization on a regular Cartesian voxel grid allows the use of fast parabolic solvers via Fourier transform of arbitrary convergence order. For the time discretization, a secondorder RungeKutta scheme is applied. The polynomial approximation of the chemical potential results in a numerical scheme that is unconditionally gradientstable and allows large time steps. With an additional preconditioner for the linear system, the condition of linear system is minimized. By this the convergence is independent of both spatial discretization and time step size. This allows for the simulation of phase separation in large porous complex domains with three dimensions and over hundred million degrees of freedom while applying arbitrary boundary conditions and using large time steps.