Impact behavior of microparticles on the flowing interface

Abstract

From the locomotion of insects on water to wet bubble scrubbing, the impact of microparticles on the flowing interface is a ubiquitous process in nature and industry. Most relevant studies have focused on the impact of microparticles on the quiescent interface and provided the regime map to describe the impact modes. Investigation of the microparticle impact behavior onto the flowing interface is presented here for the first time. Two different categories (suspension and submergence) are identified with different impact Weber number (Wep) and interface moving speed (ui). The results show that the moving film will cause the non-axisymmetric structure of impact cavity and the non-axisymmetric wetting of particle surface. The penetration time and depth of suspended and submerged particles are mainly affected by the impact Wep and particle wettability θp and are unrelated to the moving speed. The decrease in particle wettability and increase in moving speed will significantly decrease the penetration probability due to the increase of hydrodynamic force exerted on the particle, the modified penetration probability model is further purposed.