A high-order B-spline collocation scheme for solving a nonhomogeneous time-fractional diffusion equation

摘要

A high-accuracy numerical approach for a nonhomogeneous time-fractional diffusion equation with Neumann and Dirichlet boundary conditions is described in this paper. The time-fractional derivative is described in the sense of Riemann-Liouville and discretized by the backward Euler scheme. A fourth-order optimal cubic B-spline collocation (OCBSC) method is used to discretize the space variable. The stability analysis with respect to time discretization is carried out, and it is shown that the method is unconditionally stable. Convergence analysis of the method is performed. Two numerical examples are considered to demonstrate the performance of the method and validate the theoretical results. It is shown that the proposed method is of orderO(Delta x(4) + Delta t(2 - alpha))convergence, where alpha is an element of (0,1). Moreover, the impact of fractional-order derivative on the solution profile is investigated. Numerical results obtained by the present method are compared with those obtained by the method based on standard cubic B-spline collocation method. The CPU time for present numerical method and the method based on cubic B-spline collocation method are provided.