10.1063/5.0051703.3

Abstract

This paper investigates the evolution of the flow field and the load characteristics of a revolving body water entry at different angles of attack through experiments and numerical calculations. The experiment used a high-speed camera and pressure measurement devices to measure the flow field and surface pressure of water entry. A numerical calculation model was established using the computational fluid dynamics method and was used to simulate a test case. The results show that a change in the attack angle significantly affects the flow field and load characteristics of the revolving body. An increase in the angle reduces the cavity area on the upstream surface and delays the surface seal of the splash crown. The larger the angle, the smaller the difference between the peak impact pressures of adjacent cases, and the longer the time for the peak to reach a stable value (which increases approximately linearly). Meanwhile, the surface load of the revolving body is mainly concentrated around the cavity separation line, and the pressures before and after that line become dramatically different. The bottom surface load propagates from upstream to downstream in the form of ripples. Moreover, during the water entry process, the vortices around the body change from large scale to small scale. The vortices are densely attached to the surface and move upward along the test body. Interestingly, when the velocity field forms whirlpool at the wall, the surface pressure is usually less than the ambient pressure. These findings provide an important basis for a better understanding of the evolution of the flow field and surface load in the process of water entry, and further clarify the relationship between them.