DIFFERENCE-METHODS FOR SOLVING CONVECTION DIFFUSION-EQUATIONS

Difference methods for solving the convection-diffusion equation are discussed. The superiority of Allen's approximation over central or upwind differences for one-dimensional problems is confirmed, the superiority being greatest when the boundary layer is very thin. Higher order methods give improved accuracy with negligible increase in cost. A new iterative scheme is proposed for the two-dimensional problem, which requires orders of magnitude fewer arithmetic operations than existing procedures currently available in the literature. © 1990.