A mimetic finite difference method using Crank-Nicolson scheme for unsteady diffusion equation

Abstract

n this article a new mimetic finite difference method to solve unsteady diffusionequation is presented. It uses Crank-Nicolson scheme to obtain time approximationsand second order mimetic discretizations for gradient and divergence operators inspace. The convergence of this new method is analyzed using Lax-Friedrichs equiv-alence theorem. This analysis is developed for one dimensional case. In addition tothe analytical work, we provide experimental evidences that mimetic Crank-Nicolsonscheme is better than standard finite difference because it achieves quadratic conver-gence rates, second order truncation errors and better approximations to the exactsolution.Keywords: mimetic scheme, finite difference method, unsteady diffusion equation,Lax-Friedrichs equivalence theorem.