The error analysis for the Cahn-Hilliard phase field model of two-phase incompressible flows with variable density

Abstract

In this paper, we consider the numerical approximations of the Cahn-Hilliard phase field model for two-phase incompressible flows with variable density. First, a temporal semi-discrete numerical scheme is proposed by combining the fractional step method (for the momentum equation) and the convex-splitting method (for the free energy). Second, we prove that the scheme is unconditionally stable in energy. Then, the $ L^2 $ convergence rates for all variables are demonstrated through a series of rigorous error estimations. Finally, by applying the finite element method for spatial discretization, some numerical simulations were performed to demonstrate the convergence rates and energy dissipations.

Keywords

• cahn-hilliard phase field
• two-phase incompressible flows
• fractional step scheme
• energy stability
• error estimates