Shock wave’s energy transfer between different mediums

Question

This topic fascinates me, but my knowledge about shock waves — the physics behind them and the way they conduct energy — is very limited.

I wanted to ask then for some elucidations, about what happens to the kinetic energy carried by the wave when it passes from a low-density medium (such as air) to a denser one like water or even rock, and vice versa.

It is my understanding that shock waves happen when a disturbance is moving through a substance faster than information can be passed — IE faster than the local speed of sound. Now, air’s speed of sound at sea level and standard temperature is 343 m/s, while for water and rock (for example granite) that’s respectively 1,500 m/s and 5,950 m/s. As such I’d expect the shock wave to lose a lot of energy when passing from air to either one of those two substances, because they carry information much faster. But what about the opposite situation? A loss is inevitable of course, but what would be different?

Answer 1

Shock energy propagation between media of different densities is well-approximated by studying the impedance mismatches between the media. This allows the prediction of how much energy traverses the boundary separating them and how much gets reflected at that boundary. It also allows the prediction of the phase of the reflected or transmitted wave relative to that of the incident wave.

This sort of work was essential in understanding how for example the shock wave from an atomic bomb explosion behaves when it strikes the ground and then how it propagates through the ground away from the impact point.

I do not know how much of that work is in the public domain and how much is classified today but this would be a reasonable starting point for more research for you.