Mach Number=Object SpeedSpeed of Sound (Relative to local speed of sound) -When source of sound is traveling at the speed of sound, the sound waves cannot get ahead of the source, but pile up and form a shock wave. -“Sonic boom” is the effect of the pressure change. Subsonic = <.75 (NO airflow on that aircraft is above .75, such as across upper surface of wing) Transonic = .75-1.2 (Control buffering) Supersonic = >1.2 (Smooth and efficient flight.) Hypersonic = >5.0 Three types of shockwaves:
Shock wave comes off at oblique angle to surface.
Wing leading edge, nose, stabilizer leading edges.