A numerical determination of the effect of electric fields and charges on the efficiency with which cloud drops and small raindrops collide with aerosol particles

Abstract

Numerical calculations were carried out to determine the effect of a vertical electric field on the efficiency with which electrically charged or uncharged cloud drops and small raindrops of diameters ranging from 84 μm to 1.248 mm collide with electrically charged or uncharged particles of density 2 gm/cm3 and diameters between 1 and 20 μm. For this purpose, numerical flow fields about spheres of Reynolds numbers ranging from 1 to 400 were used to integrate the trajectory of the particle relative to the drop, and the force between two conducting spheres was used to represent the electrostatic force on the particle. The effect of thunderstorm strength electric charges and field on the collision efficiency was found to be highly significant for the smaller collector drops, and declined to insignificance for the largest collector drop.