Beyond spheres: water entry of small disks and cones

When a solid body enters the water with sufficiently high speed, a cavity forms that is ventilated by air from the atmosphere. The shapes and collapse mechanism of these cavities fall into four different regimes depending on the Bond and Weber numbers. The vertical water entry of spheres impacting normal to a flat free surface is perhaps the most canonical solid body entry problem and has been used extensively to study cavity dynamics. As such, the cavity regimes have not been completely characterized for other canonical impactor geometries such as disks and cones. In this study we experimentally investigate the water entry of disks and cones and show that they produce the same cavity regimes as spheres and discuss how they differ.