INFLUENCE OF SHAPED CHARGE JET STATE ON ITS INTERACTION WITH ERA FLYING PLATE

Abstract

When stretching, a Shaped Charge Jet (SCJ) is systematically subject to instabilities that disturb its surface, creating necks along it. In this article, we focus on these jet surface disturbances and their consequences on the SCJ interaction with an ERA moving plate. An experimental set-up was built to implement this interaction for different collision points, at different stand-off distances. One of the main results is the visualization of a regime change in the interaction between a SCJ and a Backward Moving Plate (BMP). A regime of deflection changes into a ligament regime interaction when the collision point stand-off is increased. This phenomenon is well captured by the ySPH simulations used to complete the phenomena analysis. Using both experimental and numerical approaches, we highlight that surface disturbances of the SCJ have a major influence on its interaction with a moving plate. Finally other simulations are performed to investigate the influence of both disturbance wavelengths and amplitudes on the interaction regimes.