A ROTATED MONOTONE-DIFFERENCE SCHEME FOR THE 2-DIMENSIONAL ANISOTROPIC DRIFT-DIFFUSION EQUATION

A rotated upwind discretization scheme is presented for the discretiza tion of the steady-state two-dimensional anisotropic drift-diffusion e quation, taking into account the local characteristic nature of the so lution. The notable features of the algorithm lie in the projection of the governing partial differential equation onto two orthogonal axes, to yield a vanishing mixed derivative term, and in the utilization of the upwind flow of information. As a result the limiting behaviour of the elliptic equation is preserved in the discretization. The scheme produces an M-matrix which guarantees an oscillation free solution and which enables the discrete system to be solved using standard iterati ve solvers. The method is illustrated by numerical examples for which the analytical solutions are known. (C) 1998 Academic Press.