Numerical solution of convection diffusion partial differential equations usually applies the third order upwind difference method, and it is common to find a solution by this finite difference approximation . As for the analytic solutions of partial differential equations, many books are published recently . However, there are not so many documents for the numerical solutions and methods. Here, we show some exercises and show the program of the C language. Based on these results, we want to discuss them about some problems and the future prospects.
