Numerical analysis of collision characteristics between charged drop and neutral droplet under uniform electric field

Abstract

Dissipatingfog and fog water collection have been of great concern recently. Corona discharge can produce charge and electric field, and accelerate the above process by promoting fog droplets collision. Collision efficiency and kernel are introduced toanalyze the effect of electric charge and electric field on fog droplets collision in this paper. For fog droplets, the efficiency and kernel represent the probability and rate of collision, respectively. In addition, an extended trajectorymodel, including drag force, gravity, electrostatic force and applied electric field force, is proposed. The results indicate that the charge promotes the efficiency and kernel significantly. However, the collision efficiency between charged drop and neutral droplet under uniform electric field is reduced. When the applied electric field strength increases, the collision efficiency first decreases and then increases to 1.0, whereas the collision kernel increases at all times. This is because the electrostatic force, hydrodynamic force and inertial force vary with electric field. The calculatedresults can be used to optimize the efficiency of fog dissipation and fog water collection.