Supersonic Wave Math Question

Einhander Sn0m4n · Post by **Einhander Sn0m4n** » 2006-03-09 09:55am

Okay, I have a question. Say we have a supersonic object (let's say, a rifle bullet) doing what comes natural and tossing a Mach wave M off its nose at angle A. There's a point X formed by two lines: L1 is parallel to the bullet's velocity vector and eventually intersects the Mach wave at angle A. L2 is a line normal to M, connecting it to X in the shortest distance possible.

What's the relatonship between the ratio of L1's length to L2's and the Mach Number?

kheegster · Post by **kheegster** » 2006-03-09 10:04am

I'm not sure I understand the geometry of the situation, but the half-angle of the shock cone, A, is related to the Mach number by

sin A = 1/M

Kuroneko · Post by **Kuroneko** » 2006-03-09 08:36pm

... from which we get L1/L2 = mach number.

Einhander Sn0m4n · Post by **Einhander Sn0m4n** » 2006-03-09 08:42pm

Kuroneko wrote:... from which we get L1/L2 = mach number.

Excellent! I was hoping for some verification of the hunch I came up with whilst sitting on the toilet earlier today...

Funny how our brains can randomly spit out scientific realizations at the strangest moments!