Lattice Boltzmann Simulation of Droplet Collision Dynamic Using Index Function Model

The phenomenon of binary droplet collision is of fundamental importance in the studies of raindrop formation, spraying processes, dispersed phase systems,and so on. Therefore, many investigations of the binary droplet collision dynamics have been performed by using experimental, numerical, and theoreticalapproaches. In this way, we simulated and studied binary droplet collision using Lattice Boltzmann twophase flow (index function model) method. LBM is anew compromising method with excellent features in two-phase modeling. Index function model which recently is presented by He, is a reliable model utilizedin this simulation. Accuracy of the model is examined by well-known basic analytical two-phase flowsincluding Laplace law and relaxation of rectangular cylinder, and our results are in good agreement with analytical outcomes which certify our final resultsquality. Two droplet collisions are simulated in different collision position such as: two equal droplets, two unequal droplets, direct collision, and offset collision.The density ratio of the liquid to the gas is fixed at 30. We used non-dimensional numbers (Reynolds, Weber) for considering different collision features (speed,viscosity force, surface tension, etc.). Binary droplet collision would result different behavior in new formeddroplet. Change in fluid specification and collision situation left various formation dynamics in new droplet. Results in variety of conditions are analyzedand compared with each other. Besides all analysis accuracy and ability of index function model for twophase flow problems is proved.

کلیدواژه ها:

Lattice Boltzmann Method ، Two-phase flow ، Droplet collision ، Index function model