Cavity dynamics in the oblique water entry of a cylinder at constant velocity

Transient cavity dynamics in the oblique water entry of a cylinder at a constant velocity is investigated. The drag force exerted on the cylinder is measured by a force sensor, and the evolution of a cavity is recorded simultaneously by a high-speed camera. A simple theoretical model, based on the decomposition of gravity force, is proposed to describe the asymmetric cavity formed in the oblique water entry. Theoretically predicted cavity shapes compare favorably with the experimental and numerical results. Moreover, it is found that with a factor indicating the effect of entry angle, the pinch-off time and position in oblique and vertical water entry problems follow the same scaling law.