The effect of a simple shear flow upon the coalescence rate of water droplets

There is some experimental evidence by Schotland (1957) and by Telford and Cottis (1964) that there is an interaction region associated with the wake of a small droplet such that other droplets inside this region eventually collide with that droplet. It is shown that the existence of such a region produces a significant collision rate between droplets of comparable size in a vertical shear flow. The general features of the collision process are in agreement with the experimental results of Jonas and Goldsmith (1972).