Impact Force Measurement of a Spherical Body Dropping onto a Water Surface from Different Heights

Abstract

The impact force of spherical body dropping onto a water surface is measured using the method which has been proposed by us. In the method, a cube corner prism is embedded in a metal spherical body. The optical center of the cube corner prism coincides with The center of gravity of the spherical body. The motion of the spherical body is measured in the optical interferometer. The velocity of the spherical body can be calculated from the Doppler frequency measured in the interferometer. The acceleration, displacement, and inertial force of the spherical body can be calculated from the velocity of the spherical body. The dropping distance of the spherical body is variable. In this experiment, the distance is set to approximately 60 mm, 150 mm, and 190 mm, so that the difference of impact force caused by the difference of initial velocity is evaluated in detail.

Comparison between numerical analysis and the levitation mass method measurement test of a spherical structure early impacting water

“…Second, the range of drop height is limited to about [60 mm, 190 mm] due to the measure capability of the digitizer. 20…”

“…The impact of a stainless sphere on the clam water surface with initial downward velocity with variable waterentry height and then plunging into the water is tested by the LMM measurement based on the Doppler effect. 19,20 The experimental setup (shown in Figure 2) divides into four systems, including water pool, the laser Doppler measurement module, quick-releasing facility, and high-speed camera.…”