LAUSR

Abstract Experiments on oblique water entry of high-speed projectiles are performed to investigate cavity evolution and impact loads. The nose shape determines the cavity behavior and consequently affects the load characteristics. Each projectile used in the experiments has a truncated-cone head and a cylindrical body. The geometry of the truncated cone is defined by two dimensionless parameters. We adopt 40 kinds of head shape, while the impact velocity (41 m/s) and impact angle (30°) are kept the same. The cavity and load characteristics are investigated using a high-speed camera and an acceleration sensor, respectively. We divide the cavity dynamics into two types. In one type, the first cavity develops and coalesces with the second cavity, leading to the formation of a single continuous cavity. In the second type, the closure of the first leading cavity occurs on the truncated-cone head or the cavity may collapse onto the head in later stages, causing the two cavities develop independently without coalescence. We also find that the transient impact load and the cavity dynamics are closely related, which has not been discussed in detail in previous studies. The quantitative relationship between the load peaks and the two dimensionless parameters is revealed.