A linear adaptive second‐order backward differentiation formulation scheme for the phase field crystal equation

Abstract

In this article, we present and analyze a linear fully discrete second order scheme with variable time steps for the phase field crystal equation. More precisely, we construct a linear adaptive time stepping scheme based on the second order backward differentiation formulation (BDF2) and use the Fourier spectral method for the spatial discretization. The scalar auxiliary variable approach is employed to deal with the nonlinear term, in which we only adopt a first order method to approximate the auxiliary variable. This treatment is extremely important in the derivation of the unconditional energy stability of the proposed adaptive BDF2 scheme. However, we find for the first time that this strategy will not affect the second order accuracy of the unknown phase function by setting the positive constant large enough such that The energy stability of the adaptive BDF2 scheme is established with a mild constraint on the adjacent time step radio . Furthermore, a rigorous error estimate of the second order accuracy of is derived for the proposed scheme on the nonuniform mesh by using the uniform bound of the numerical solutions. Finally, some numerical experiments are carried out to validate the theoretical results and the efficiency of the proposed scheme combined with the time adaptive strategy.

A Linear Doubly Stabilized Crank-Nicolson Scheme for the Allen–Cahn Equation with a General Mobility

“…4 in [15]. There already exist several efficient time-adaptive strategies [13,14,29,32,33,35] that can be used in conjunction with numerical schemes with variable time steps. We will exploit the use of the following robust time adaptive strategy with the CN scheme (2.10) in the simulation, which is based on the energy variation [32] to efficiently simulate the coarsening dynamic process: is a positive constant parameter.…”