# Mach reflection

Hello guys,

I want to compute reflected pressures in Mach reflection region. In Mach reflection, let's just think about the reflected, incident and merged pressures (of Mach stem). You know, the merged pressure is created by coalescing the incident and reflected pressures. Assuming that all the pressures are straight lines, can I simply calculate the merged pressure given that the incident and reflected pressures are known at the moment of transition from regular to Mach reflection?

Or is the merged pressure just the sum of the scalar values of two pressures independent of the angle of incidence and reflection? If so, the reflected pressure from the merged pressure will be always larger than the reflected pressure before Mach reflection. But, this might be not true because I have to consider dynamics pressures as well as static pressures. I have difficulties of handling the two different kinds of pressures in the calculation of the merged pressure and the reflected pressure from it after Mach reflection.

Thank you,
Lasfoe

## Answers and Replies

Bobbywhy
Gold Member
I will not pretend to understand what you are asking. I have studied shock stems and how they behaved during the atomic bomb explosions over Hiroshima and Nagasaki. Just maybe these resources will be useful:

The term shock polar is generally used with the graphical representation of the Rankine-Hugoniot equations in either the hodograph plane or the pressure ratio-flow deflection angle plane. The polar itself is the locus of all possible states after an oblique shock.
http://en.wikipedia.org/wiki/Shock_polar

For the behaviour of shock waves traveling normal to the prevailing flow see:
http://en.wikipedia.org/wiki/Rankine-Hugoniot_equation