Charge separation associated with splashing of water drops on solid surfaces

Abstract

Our laboratory experiments show that the charge separation when water drops splash on a brass surface is about an order of magnitude higher than when they splash on surfaces typical of ground surface, such as soil, silica or grass on which raindrops generally splash on the earth's surface. The change being separated has been observe to increase as the drop diameter increases from 3.6 to 7.0 mm. The size distribution of fragment droplets which result from a splash show that the total number of fragments is much larger when the splash occurs on brass surface as compared to that when it occurs on the soil, silica or grass surface. The results indicate that small drops in the range of 5.8 to 7.0 mm diameter are more efficient in changing the kinetic energy of the drop to electrical energy. Results of the experiment have been used to estimate the charge that is generated when raindrops splash on ground. Results of the experiment have been discussed in terms of the hardness of the target surface and the degree of violence of the splash.