Collisions of water drops in a gas-vapor environment at high temperatures and vapor concentrations

Abstract

The study of the characteristics of secondary droplet atomization, leading to formation of an aerosol cloud of polydisperse child droplets appears to be promising. It is topical to assess the influence of properties of liquid and gas medium on the position of transition boundaries between the regimes of drop collisions and characteristics of the formed child droplets. This article presents the experimental results for the characteristics of drop collisions at various temperatures of the liquid and gas-vapor mixture and water vapor concentration in the latter with the aim of developing the prospective heat and mass transfer gas-vapor technologies. For this purpose, we have created the experimental setup that allows varying the relative humidity of gas-vapor mixture in the area of drop collisions from 20% to 100%, its temperature from 20?C to 100?C and the temperature of the liquid from 20?C to 90?C. The test fluid is water. The collisions are recorded by a high-speed video camera. The consequences of collision and the boundaries between them on the regime maps are determined in accordance using the approach, distinguishing: bounce, coalescence, separation, and disruption.