Investigation of collision-induced breakup of raindrops by numerical simulations: First results

Collision-induced breakup resulting from binary collisions of large drops has been investigated in the past by very few laboratory experiments. This process is here investigated using a 3D-CFD program based on direct numerical simulation. Besides same drop pairs as considered in the measurements also a number of additional ones are taken into account in order to complete the parameter space. First results with respect to coalescence efficiencies and fragment size distributions show some similarities to the findings of the past laboratory experiments but also certain differences. Excentricity of the collision event is responsible for the various breakup modes.