Numerical analysis of the inhomogeneous obstacle influence on the precursor shaped charge warhead performance

Purpose of the precursor shaped charge warhead is to initiate the Explosive Reactive Armor (ERA) and thus provide an unobstructed path to the jet of the main shaped charge. The precursor warhead is most commonly placed in the front of the missile where it is surrounded by other subsystems. All of the subsystems which lay on the path of the precursor warhead’s shaped charge jet represent the obstacle that will decrease its efficiency. The goal of this paper is to analyze the precursor warhead’s performance in a case where the inhomogeneous obstacle is placed in front of it. The numerical analysis of the obstructed formation process was performed in order to determine the properties of the formed jet using ANSYS AUTODYN 2D software. For the existing missile configuration, jet formation process and precursor warhead's performance against ERA were analyzed numerically. Significant differences in formed jet's properties were observed for the simulations with and without the inhomogeneous obstacles. In the case of inhomogeneous obstacle it is present decreasing of jet tip velocity for around 23%, decreasing of jet tip dimaeter for around 50% and jet time are delayed in contact with ERA front panel for around 10 µs. Obtained results indicate that in the observed cases, formed jet has enough energy to initiate the explosive reactive armor.