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arXiv · 1410.8846

A decoupled unconditionally stable numerical scheme for the Cahn-Hilliard-Hele-Shaw system

Daozhi Han
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Abstract

We propose a novel decoupled unconditionally stable numerical scheme for the simulation of two-phase flow in a Hele-Shaw cell which is governed by the Cahn-Hilliard-Hele-Shaw system (CHHS) with variable viscosity. The temporal discretization of the Cahn-Hilliard equation is based on a convex-splitting of the associated energy functional. Moreover, the capillary forcing term in the Darcy equation is separated from the pressure gradient at the time discrete level by using an operator-splitting strategy. Thus the computation of the nonlinear Cahn-Hilliard equation is completely decoupled from the update of pressure. Finally, a pressure-stabilization technique is used in the update of pressure so that at each time step one only needs to solve a Poisson equation with constant coefficient. We show that the scheme is unconditionally stable. Numerical results are presented to demonstrate the accuracy and efficiency of our scheme.

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Daozhi Han. 2014-10-31. A decoupled unconditionally stable numerical scheme for the Cahn-Hilliard-Hele-Shaw system. https://arxiv.org/abs/1410.8846

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