Error estimate of virtual element approximation for loaded time-fractional Hallaire’s equation
摘要
The issue we address in this paper is to propose a virtual element analysis for the nonlinear Hallaire equation as a modified version of the nonlinear diffusion equation with a time-fractional derivative. The spatial direction is discretized by the virtual element method. The upper limit of error related to the solution of the space-discrete scheme and the exact solution is obtained. To get an optimal error estimate, the mesh-graded time discretization approach is employed to approximate the Caputo fractional derivative. Also, a second-order technique is used to approximate the nonlinear terms. Then, a fully-discrete scheme is constructed. The unconditional stability and order of convergence of the presented numerical formulation are proved in separate theorems. Finally, two test problems examined the theoretical results of this paper.