An influence of explosive geometry on shaped charge jet performance

Abstract We have measured the velocities of the particles of a jet after breakup and found that the distribution contained an approximately constant velocity section of several particles immediately behind the tip. The jet was produced from a centrally initiated, 38 mm diameter conical shaped charge. Since the measurements were carried out after jet formation, the observation is not considered to be directly related to the inverse-velocity gradient effect that produces the tip particle. Comparison between calculated and measured jet penetration velocities show that the calculations assuming a uniformly stretching jet require modification to take account of the observation. A possible explanation for the origin of the non-ideal behaviour is that the short height of explosive between the detonator and liner (the explosive head height) produces a building detonation which strikes the liner with a varying impulse and curvature. Some support for the observation is found in earlier experimental work by DiPersio et al1 and in a numerical modelling study by Coughlin2.