Detonation Wave Generated by a Hypervelocity Projectile

Recent experimental results on generation of oblique detonation waves over hypervelocity projectiles launched into detonable gaseous mixtures are reported. Eighty-degree-apex-angle-cone cylinders were launched at about 3 km/sec into an optical visualization chamber placed inside a 1.7-m diameter and 12-m long recovery chamber of a two-stage light gas gun at the Shock Wave Research Center. The visualization chamber was filled with reactive mixtures of hydrogen/oxygen and hydrogen/oxygen/nitrogen at various initial pressures. The detonation waves generated are observed with double exposure holographic interferometry and also sequentially recorded with a highspeed video camera capable of recording one hundred frames at one million frames per second. The result of observations clearly shows detonation waves and wakes behind high-speed projectiles. This is an experimental counterpart of the numerical result presently in progress in UTIAS, in which the detonation wave structure is going to be compared.