Recent content by rbogie

Thanks a lot for the excellent collection of data. I took another look at the set of pictures on Wikipedia that shows the engine/spike at different Mach values and when you look very closely you can see that at Mach 3.2 with the spike retracted 26 inches, the shockwave is just barely attached...

I've been reading about the SR-71 and the J58 engine and I'm confused about what I've read about the inlet spike. The spike would start out extended 3 feet but as speed (Mach) went up it would retract, up to 26 inches when at Mach3.2. This confuses me as I thought you'd always want the...