A time-adaptive finite volume method for the Cahn-Hilliard and Kuramoto-Sivashinsky equations

This paper presents a complete finite volume method for the Cahn-Hilliard and Kuramoto-Sivashinsky type of equations. The spatial discretization is high-order accurate and suitable for general unstructured grids. The time integration is addressed by means of implicit an implicit-explicit fourth order Runge-Kutta schemes, with error control and adaptive time-stepping. The outcome is a practical, accurate and efficient simulation tool which has been successfully applied to accuracy tests and representative simulations. The use of adaptive time-stepping is of paramount importance in problems governed by the Cahn-Hilliard model; an adaptive method may be several orders of magnitude more efficient than schemes using constant or heuristic time steps. In addition to driving the simulations efficiently, the time-adaptive procedure provides a quantitative (not just qualitative) characterization of the rich temporal scales present in phase separation processes governed by the Cahn-Hilliard phase-field model. (C) 2008 Elsevier Inc. All rights reserved.