Fireball and shock wave dynamics in the detonation of aluminized novel munitions

High-speed 4-kHz visible imagery from 13 field detonations of aluminized RDX munitions with varying liner compositions are collected to study shock wave and fireball dynamics. The Sedov-Taylor point blast model is fitted to shock front temporal history data, and blast wave characteristics are interpreted by varying the energy release factor s and blast dimensionality n. Assuming a constant rate of energy release (s = 1), the Sedov-Taylor model establishes a nearspherical expansion with the dimension n = 2.2-3.1 and shock energies of 0.5-8.9 MJ. These shock energies correspond to efficiencies of 2-15% of the RDX heats of detonation. A drag model for the fireball size yields a maximum radius of a parts per thousand 5 m, which is consistent with the luminous fireball size in visible imagery, and initial shock speeds corresponding to Mach numbers of 4.7-8.2. Initial shock speeds are smaller than the RDX theoretical maximum speed by a factor of 3-4. Shock energy decreases if aluminum is in the liner rather than in the high explosive.