Experimental investigations of steady-state oblique detonation waves generated around hypersonic projectiles

Five-mm-diameter projectiles, whose speed was beyond the Chapman-Jouguet (C-J) detonation speed, were fired into mixtures containing stoichiometric hydrogen-oxygen gases plus argon diluents. The flowfield around the projectile was visualized using a CCD camera. We measured the minimum normal velocity components of detonation waves around the projectiles and the effective curvature radius of a bow detonation wave near the projectile tip. From these experimental results we concluded that the steady-state C-J detonation wave is stabilized around a projectile when the effective curvature radius of the bow detonation wave is larger than 8.6 times of the detonation cell size.