Investigation of dust lifting by a moving shock wave based on compressible multiphase particle-in-cell method

Abstract

A dust lifting process by shock waves performs high complexity and is of significance for industrial safety. To develop an in-depth understanding of an inherent physical mechanism of dust lifting, this study presents a detailed consideration regarding particle force models. First, a set of compressive force models of those that may affect lifting is distinguished, which afterwards is integrated into the original compressible multiphase particle-in-cell (CMP-PIC) method. Second, the value of the restitution coefficient is determined using the sensitivity analysis method. Good agreement of the dust lifting height is achieved between the numerical and different experimental results, which demonstrate the reliability of the CMP-PIC method. Then, the contributions of different kinds of forces to dust lifting are qualitatively and quantitatively analyzed. Flow field analysis shows that the shock-induced flow produces downward drag and pressure gradient forces on the particles to inhibit the rise of the particles, while the Magnus and Saffman forces perform a promoting role. Additionally, the compression wave and its reflected wave in the granular medium are clearly observed. Specially, when the reflected wave reaches the surface, huge collision forces on the particles and significantly promotes the initial lifting of particles. Moreover, the histories of forces acting on the particles at different layers of dust are discussed. The results show that different kinds of forces perform intense space-time dependent characteristics, and the dominant forces at different stages of dust lifting are identified. A dimensionless analysis of the force model qualitatively justifies the simulation results. The influence of the shock strength is also discussed.