Droplet impingement and breakup on a dry surface

In this work, new results of droplet impingement and breakup have been obtained using three-dimensional lattice Boltzmann method. All four phases after impingement, the kinematic, spreading, relaxation and equilibrium phases, leading to breakup have been obtained for a range of Weber number, Reynolds number and density ratio. Conditions have been chosen such that Re≪We for comparison with available data in the literature. The maximum spread factor compares well with experiments as well as the theoretical value of 0.5 Re0.25. At Oh < 0.15 and Capillary number, Ca < 1.0, the relaxation phase is marked by the presence of strong oscillations in the spreading diameter. An analytical solution for breakup based on the conservation of energy is provided. Criteria for three-dimensional droplet breakup have been developed as functions of Re and We.