Drop breakup and drop pair coalescence using front-tracking method in three dimensions

In this paper, the deformation, breakup of a drop in shear flow and drop pair coalescence are studied using a finite difference/front tracking method. The drop deformation in shear flow was first studied in a Stokes regime and was compared with experimental and numerical results. A new algorithm that changes the topology of the interface dynamically and globally was developed to study drop break-up in shear flow after reaching a critical limit. Break-up simulation was first carried out in a Stokes regime. To validate the method performance and topology changing algorithm, results were compared with other numerical methods. Moreover, by obtaining a critical capillary number at finite Reynolds numbers and comparing the results with available data in this area, good agreement was observed that shows the ability of the method and the present topology changing algorithm. Different coalescence regimes for drop pair collision were also captured using the present topology changing algorithm. The present method is capable to simulate other multiphase flow problems that to some extent include collision and breakup of drops.