TY - JOUR T1 - A BDF2-SSAV Numerical Scheme with Fourier-Spectral Method for a Droplet Thin Film Coarsening Model AU - Zhang , Juan AU - Dong , Lixiu AU - Zhang , Zhengru JO - Numerical Mathematics: Theory, Methods and Applications VL - 3 SP - 777 EP - 804 PY - 2024 DA - 2024/08 SN - 17 DO - http://doi.org/10.4208/nmtma.OA-2024-0016 UR - https://global-sci.org/intro/article_detail/nmtma/23374.html KW - Droplet coarsening model, scalar auxiliary variable, Fourier-spectral method, energy stability, optimal rate convergence analysis. AB -

A linear and second order numerical scheme is proposed and analyzed for a droplet thin film coarsening model, with a singular Leonard-Jones energy potential involved. This numerical scheme with unconditional energy stability is based on the backward differentiation formular (BDF) method in time derivation combining with the stabilized scalar auxiliary variable approach in time and the Fourier spectral method in space. A second order accurate artificial regularization term, in the form of $S∆(\phi^{n+1}− 2\phi^n + \phi^{n−1}),$ is added in the numerical scheme to make better stability of the numerical scheme. Moreover, we present the detail proof for unconditional energy stability property of the numerical scheme, without any restriction for the time step size. In addition, an $\mathcal{O}(∆t^2+h^m)$ rate convergence estimate in the $ℓ^∞(0, T ; ℓ^2)$ norm are derived in details with the help of a priori assumption for the error at the previous time step. Some numerical simulation results are presented to demonstrate the efficiency and accuracy of the second-order numerical scheme.