Collision of water drops with a plane water surface

Abstract

The dependence of the outcome of the collision of uncharged water drops with a plane water surface on the impact angle α, the velocity v1 and the radius r1 of the drops has been investigated experimentally. The impact parameters were varied over the intervals: v1=0.40-1.05 m/sec, r1=75-150 μm, and α=16-85°. The method employed made it possible to avoid having to monitor the individual high-speed impact process. A stream of drops, produced in a "vibrating reed" type monodisperse droplet generator, was directed at the target. The impact parameters were measured by means of pulsed illumination. The results are expressed in the form of the dependence of the rebound probability and the coalescence coefficient ES on the impact parameters. The existence of alternating conditional rebound-coalescence-rebound zones for different impact angles is established, together with a decrease in ES with increase in r1 and v1. The data obtained generalize the results of previous experiments. © 1990 Plenum Publishing Corporation.