Hello, I am currently using Maccormack's scheme to solve for a 2D super sonic flow in a channel using Euler's Eqns. I am getting reasonable results except for the fact that my code does not converge. The residual first increases, then remains at the same value for thousands of iterations. I don't know what to do now. I tried fiddling with the pressure triggered artificial viscosity terms but it's still the same. Does anybody have any suggestions?? Thanks a lot. dinu

(1). You need to monitor the actual computed variables and plot the value vs iteration number at a number of key locations. (2). For the flow field, you should use contour plots to check the difference between iterations, say every 100 iterations, to find out the areas where the flow field is still changing or oscillating. (3). Once you have identify the problem areas, then you can find out what's wrong with the program.