Study on Kinetic Threshold of Raindrop Splash Bubble Sound

Abstract

Rainfall noise is mainly composed of the initial impact sound and bubble sound. Bubbles are divided into three categories according to the diameter of the raindrops. It is generally believed that only a small raindrop hitting the water surface will produce the first type of bubble, larger diameter rains will only produce the second and third types of bubbles. In this paper, in order to verify the relationship between the diameter of raindrops and the type of bubbles, experiments were carried out to hit free water surface with different particle sizes of raindrops, The critical conditions for the raindrops to hit the water surface and generate air bubbles are found, and the kinetic thresholds of the raindrops under the critical conditions are obtained. The results show that in addition to the generally considered small raindrops will produce the first type of bubbles, the large raindrops and great raindrops will also produce a certain level of bubbles. Kinetic energy threshold is not a constant, but with the diameter and height of the drop