Measurement and analysis of motion characteristics of vapor clouds induced by aluminum-aluminum hypervelocity impact

A sequenced imaging method for obtaining the velocity of the impact-induced vapor shock wave is designed according to the generating mechanisms and radiation characteristics of vapor clouds in hypervelocity impacts. Tests were conducted for 2A12 aluminum plates being impacted by aluminum spheres with a diameter of 4.5 mm and velocity of 6 km/s. Sequenced images of the movement of the impact-induced vapor shock wave were obtained. The expanding radius, the velocity of the vapor shock wave, the total energy of the vapor clouds and the distribution of parameters in the flow field behind the shock wave, etc., were quantitatively analyzed. It is revealed from the results that the location information of the impact vapor shock wave at different times can be obtained properly by the designed measurement method, providing data for analyzing the motion characteristics of the vapor cloud. The measured expansion of the vapor wave radius with time is consistent with fitting results of the Taylor model, proving that the Taylor model theory can be used for studies related to hypervelocity impact vaporization.