COALESCENCE AND SEPARATION IN BINARY COLLISIONS OF LIQUID-DROPS

An extensive experimental investigation of the binary collision dynamics of water drops for size ratios of 1, 0.75, and 0.5, for the Weber-number range of 1 to 100, and for all impact parameters is reported. Two different types of separating collisions, namely reflexive and stretching separations, are identified. Reflexive separation is found to occur for near head-on collisions, while stretching separation occurs for large-impact-parameter collisions. The boundaries between both of the separating collisions and coalescence collision are found experimentally. Theoretical models for predictions of the reflexive and stretching separation are also given.