LAUSR

Abstract Droplet impact onto thin film is a ubiquitous phenomenon in many industrial applications. In the present study, the VOF method is adopted to simulate the crown evolution during the impact process with different surface tension coefficient, viscosity and gravity. Especially, the crown behavior is investigated in the energy aspect. The kinetic energy, gravitational potential energy, surface energy and viscous dissipation are taken into consideration. The results reveal that higher surface tension coefficient leads to larger crown diameter. The evolution of gravitational potential energy can be divided into three phases: decrease phase, increase phase and collapse phase. Similarly, the evolution of surface energy can be divided into four phases: increase phase, drop phase, flat phase and collapse phase. The drop phase is caused by the film rupture in the center zone. In the case with zero gravity the flat phase is replaced by a second increase phase. In particular, it is found that larger viscosity will postpone the film rupture and the film even doesn't break at high viscosity.