Explanation

Let's simulate the shock wave hit the wall obliquely and follow its evolution after the reflection. This problem is a fundamental test problem of 2 Dimensional simulation code.

[Initial Condition] We assume an oblique shock wave moving toward the reflection wall (botton of the figure) at the angle of 30 degree. The density and pressure ratios of the lime green and the black regions are 8.0:1.4 and 116.5:1.0, respectively. The shock wave is moving with 1.83 times of the sound speed. In the figure, color shows density, arrows show velocity. Density is decreasing from Red, to Orange, Olive, Green, Aqua, Blue, Perple, and Black.

[Evolved Stage] The shock wave hits the wall and the reflected shock wave and original shock waves collide each other. As a result, a region with high density and pressure is formed by these two shock waves and complicated structure as seen in the figure is formed.