A Birth-Death Process Model on Collision and Coalescence of Drops in Gas/Drop Flows

摘要

To analyze the change of droplets number caused by collision and coalescence in gas/droplet two-phase flows, a stochastic model was established, in which the collision probability of two drops with different sizes was derived and the stochastic process theory was introduced to describe the change of drops number when the phenomenon of collision and coalescence takes place. By considering the immigration and emigration and collision of the droplets located at a fixed region, it was found that the number of drops is a birth death process, and the relevant model equation was derived. The stationary distribution and its mean value were obtained by analyzing the number characteristic of the birth-death process. These results are helpful to explain the mass exchange between drop classes in gas/drop two phase flows.