A LABORATORY INVESTIGATION OF COLLISION EFFICIENCIES, COALESCENCE AND ELECTRICAL CHARGING SIMULATED CLOUD DROPLETS

Abstract

A laboratory experiment is described in which liquid drops are formed in a viscous medium to simulate cloud droplets in air by equating the Reynolds number for the experiment to that of the atmospheric case. Certain characteristics of the behavior of drops of various liquids in different viscous media are described. Collision efficiencies and droplet trajectories differing markedly from previous theoretical calculations are presented for a limited number of drop sizes. The coalescence of water drops falling through mineral oil, and of water drops suspended in air, is found to be a function of the strength of an applied electrical field. An efficient drop-charging process is suggested by the experiment and is proposed as a hypothesis for cloud and thunderstorm electrification.