Abstract
The lattice Boltzmann method for two-phase flow is applied to the simulations of binary droplet collisions with the size ratio of 0.5 for various Weber numbers of 30 < We < 83, impact parameters of 0 ≤ B ≤ 0.75 and Reynolds numbers of 3000 < Re < 4900. The density ratio of the liquid to the gas is fixed at 50. The results are classified into the three collision formations such as coalescence, reflexive separation, and stretching separation. The boundaries between the three types of collisions are compared with existing theoretical predictions. The mixing processes are also simulated for various Weber numbers at B=0 to investigate the mixing rate during separating collisions, and the relation between the mixing rate and the Weber number is obtained.
