Encapsulation and separation in collision between immiscible liquid drops

Studies on binary drop collisions have been performed in literature to understand the physical phenomena which occur during the process. They also have applications of interest in modelling engines for example, where collision and coalescence are likely to be prevalent due to the dense nature of the sprays and the low droplet-droplet distance. In the present study, the collision behavior of two immiscible liquid drops namely a water drop and an n-Heptane drop of varying drop size ratios has been investigated experimentally. Experiments were performed at an atmospheric environment of 298 K and 101.325 kPa. Two mono-disperse droplet streams generated by piezoelectric droplet stream generators were used for the collision study. Collision outcomes were studied for size ratio of 1, at different Weber-numbers for non-dimensional impact-parameter B.The results from the experiments describe the boundaries of collision outcomes namely encapsulation and separation as a function of the impact parameter B and relative velocity Ur