The performance of a numerical scheme on the variable-order time-fractional advection-reaction-subdiffusion equations

This paper is concerned with a highly accurate numerical scheme for a class of one and two-dimensional time-fractional advection-reaction-subdiffusion equations of variable order alpha(x, t) is an element of (0, 1). For the spatial and temporal discretization of the equation, a fourth order compact finite difference operator and a third-order weighted-shifted Grunwald formula are applied, respectively. The stability and convergence of the present scheme are addressed. Some extensive numerical experiments are performed to confirm the theoretical analysis and high-accuracy of this novel scheme. Comparisons are also made with the available schemes in the literature. (c) 2022 IMACS. Published by Elsevier B.V. All rights reserved.