Dynamic-stabilization-based linear schemes for the Allen-Cahn equation with degenerate mobility: MBP and energy stability
Hongfei Fu, Dianming Hou, Zhonghua Qiao, Bingyin Zhang
TL;DR
This work addresses the Allen–Cahn equation with general, including degenerate, mobility by introducing a dynamic stabilization framework that yields MBP preservation and energy stability at the discrete level. It develops a first-order DsBE scheme and a second-order DsCN scheme that, through a novel prediction–correction approach and a cut-off preprocessing step, require only a single linear solve per time step while maintaining unconditional mobility-robust MBP and energy dissipation. The authors prove maximum-norm error estimates for both schemes and establish mobility-robust energy stability despite degeneracy in the mobility function. Numerical experiments across constant and degenerate mobilities, including 3D simulations, validate the theoretical results and demonstrate improved efficiency via adaptive time stepping and robust long-time dynamics under degenerate mobility.
Abstract
In this paper, we investigate linear first- and second-order numerical schemes for the Allen--Cahn equation with a general (possibly degenerate) mobility. Compared with existing numerical methods, our schemes employ a novel dynamic stabilization approach that guarantees unconditional preservation of the maximum bound principle (MBP) and energy stability. A key advance is that the discrete energy stability remains valid even in the presence of degenerate mobility-a property we refer to as mobility robustness. Rigorous maximum-norm error estimates are also established. In particular, for the second-order scheme, we introduce a new prediction strategy with a cut-off preprocessing procedure on the extrapolation solution, and only one linear system needs to be solved per time level. Representative numerical examples are provided to validate the theoretical findings and performance of the proposed schemes.
