Experimental analysis on oblique water-entry of asymmetric-headed moving bodies

Abstract:

To explore the cavity evolution and ballistic characteristics during the oblique water-entry of asymmetric structures, experimental research was conducted on various asymmetric-headed bodies. High-speed imaging technique was utilized to capture the cavity evolution and body position during the water-entry process of asymmetric-headed moving bodies. Utilizing digital image processing, trajectories and attitudes of these bodies were extracted. A comparative analysis was then performed to assess the impact of head shape and entry mode on cavity evolution and ballistic characteristics. The results show that the evolution of the water entry cavity of asymmetric-headed moving bodies has unique cavity flow characteristics such as secondary open cavity, secondary splashing, primary cavity attachment, cavity fusion, and secondary cavity collapse. The shape of the head of the moving body will seriously affect the evolution of the water-entry cavity and the ballistic characteristics of the moving body. As the shape of the head of the moving body changes from a convex shape to a concave shape, the width of the splash water curtain, the size of the cavity curtain, the size of the cavity and the attitude angle of the moving body will gradually increase. On the contrary, the closure time of the secondary cavity will gradually decrease. This characteristic has a profound impact on practical engineering applications.