SR71
------------------------------------------------------------------------------------
"I guess its the three dimensional equivalent of the area velocity relation in quasi one dimensional flow:
dA/A=(M^2-1)*(du/u)
Integrate the pressure over the geometry of a convergent divergent intake and you should obtain the result".
------------------------------------------------------------------------------------
I must confess that I haven't got a clue what you're talking about, but that's my problem, not yours.
However, with the greatest respect, I don't think there's anything very straightforward about SR71 performance in relation to the behaviour of the high supersonic shock systems. My (limited) understanding is that the actual flight test programme was a huge surprise in certain areas, and that some aspects of this are still classified today... But I fully accept you may know more.