Dynamics of rebound in head-on collisions between suspended micrometer-sized droplets and particles

Rebounding phenomena occurring during the interaction between dust particles and droplets are a significant factor contributing to the inefficacy of dust reduction methods. However, existing literature has not quantitatively elucidated the mechanics of rebounding during collisions between micrometer-sized suspended droplets and particles. To address this gap, the present study developed a multiphase numerical simulation model employing the volume-of-fluid (VOF)–level set method and dynamic mesh techniques to investigate rebounding dynamics. A theoretical model was proposed to predict the rebounding threshold, integrating factors such as sample size, droplet surface tension, droplet viscosity, droplet–particle diameter ratio, droplet–particle density ratio, and contact angle hysteresis. By applying specific parameters to this model, the study examined the impact of these key factors on the effectiveness of dust reduction. Additionally, the research proposed several strategies to optimize spray parameters and additives. The findings provide a crucial foundation for advancing dust suppression technologies and other industrial applications, including spray drying, coating technologies, and inkjet printing.