What happens if two moving shock waves collide?

[DigedyDan]

Say there were to be two normal shock waves that were moving towards each other at different speeds. What would happen when they collide with each other? Would the shock waves flow past each other or would they be reflected back from the direction they came from? Also how would you be able to determine how the shock waves would change in velocity after passing through each other, reflecting, or whatever it is that they do?

I'm not sure if I'm describing it well enough, so I'll try to draw it out.
shock @ speed X air moving at speed Y shock @ speed Z
|->x ( -->y ) z<-|

which then becomes

a<-| ( -->b ) |->c

 

[TheQuietOne]

Logically speaking, it doesn't seem that the air movement would make much difference (depending on the strength of the waves)

 

[DigedyDan]

So the velocity of the air in the middle would only change the reference frame? As in if you were to make Y=0m/s, then the two shocks would be X-Y and Z+Y respectively?

EDIT: This seemed to have worked, and it matched with given calculations for before the shocks collide with each other. However, I still do not know what happens when the shocks do collide.

 

[anorlunda]

What happens when supersonic warplanes fly past each other on opposite courses? Photographic evidence probably exists somewhere.

Are there any NASA experts reading this thread?