Summary

As with normal shock, the oblique shock with upstream Mach number, $M_1$ is always greater than 1. However, in oblique, as oppose to the normal shock, the downstream Mach number, $M_2$ could be larger or smaller then 1. The perpendicular component of the downstream Mach number, ${M_1}_n$ is always smaller than 1. Given $M_1$ and the deflection angle, $\delta$ there could be three solutions: the first one is the ``impossible'' solution in the case where D is negative, two is weak shock, and three is strong shock. When D is positive there is no physical solution and only normal shock exist. When D is equal to zero, a special case is created because the weak and strong solutions are equal (for large deflection angle). When $D > 0$ , for large deflection angle, there is a possibility of no two-dimensional solution resulting in a detached shock case.