Criticality for stabilized Chapman-Jouguet oblique detonation wave around sphere bodies in acetylene-oxygen-krypton mixtures

The criticality for the C-J detonation waves was studied. The first expression of the criticality was a mean-curvature coefficient, a rate between a detonation cell width and a mean-curvature radius in which the normal velocity component was the Chapman-Jouguet (C-J) velocity, was 5.03 The mean-curvature coefficient was constant and did not depend on the type of mixture (H₂-O₂-Ar or C₂H₂-O₂-Ar), initial mixture pressure, projectile diameter, projectile velocity nor diluent mole fraction. A more accurate mean-curvature coefficient for stabilized oblique C-J detonation around symmetric sphere bodies in highly-krypton-diluted acetylene-oxygen mixtures having extremely low C-J velocities was obtained. The mean-curvature coefficient of 7.8 was the most important value for stabilizing the self-sustained oblique detonation waves around multi-dimensional bodies. A lower velocity projectile could stabilize a self-sustained oblique detonation wave more effectively than could a higher velocity one. In the high projectile velocity region, the experimental critical condition was inconsistent with Lee's detonation initiation theory. A semi-empirical criticality equation for the stabilization, which was the secondary expression of the criticality and identical with the present and past experimental results, was proposed. Original is an abstract.