Experimental Study of a Sphere Bouncing on the Water

Abstract

In this paper, the flow physics and impact dynamics of a sphere bouncing on a water surface are studied experimentally. During the experiments, high-speed camera photography techniques are used to capture the cavity and free surface evolution when the sphere impacts and skips on the water surface. The influences of the impact velocity (v ₁) and impact angle (θ ₁) of the sphere on the bouncing flow physics are also investigated, including the cavitation evolution, motion characteristics, and bounding law. Regulations for the relationship between v ₁ and θ ₁ to judge whether the sphere can bounce on the water surface are presented and analyzed by summarizing a large amount of experimental data. In addition, the effect of θ ₁ on the energy loss of the sphere is also analyzed and discussed. The experiment results show that there is a fitted curve of ${v}_{1}=17.5{\theta }_{1}-45.5$ determining the relationship between the critical initial velocity and angle whether the sphere bounces on the water surface.

Keywords

Water entry / Bouncing sphere / Critical impact angle / High-speed photograph / Splash

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