Influence of the Concentration of Water Droplets in an Aerosol Cloud on the Characteristics of their Collisional Interaction

Abstract

The authors have presented results of experimental investigations into the process of collisions of water droplets in a gas medium with variation of the basic parameters in wide ranges corresponding to advanced gas-vapor-droplet technologies: sizes (radii) 0.1???1 mm, velocities of travel 0???10 m/s, angles of interaction (attack) 0???90o, relative volume concentration 0.1???10???3???8.5??10???3 m3 of water/m3 of the gas, velocity of motion of the flow 0???10 m/s, and temperature 20???1000oC; directions of flows: opposing, codirectional, and lateral. In processing the experimental results, the emphasis was on the influence of the relative volume concentrations of the droplets on the characteristics of their interaction. The relative probabilities of four typical regimes of interaction of the droplets have been calculated: recoil, coagulation, spread, and breakup (reduction in size). Parametric ranges have been shown for droplets for which the concentration growth of the latter in an aerosol leads to an increase in the probability of coagulation, recoil, and size reduction. Also, the authors have presented ranges of variation of the concentration of droplets in a gas medium, in which the probabilities of all the investigated interaction schemes are high. The experimental results have been processed with the existing approaches to generalization by calculating the angular factor of interaction and the Weber number.