Study on the Attenuation Effect of Water Protection Layer on the Velocity of Jet Tip

In the present work the process of the jet penetrating the interval target of a water protection layer was observed using flash X-ray photography, the variations of the jet tip velocity and the distribution characteristics of the metal particles and shock waves in water were obtained, and the phenomenon in the experiment were discussed in combination with the mechanism of water on the metal jet at high temperature.The result shows that the jet tip velocity would drop during the jet penetrating the water protection layer.This is mainly due to the fragmentation resulting from the high pressure (9-10 GPa) and high temperature after the shock wave of the jet.Besides, the fragmentation of the jet tip is the most serious in the early stages of the jet entering the water protecting layer, which results in a fast consumption of the jet tip and the false image of the jet tip's velocity drop in the test of the flash X-ray measurement.