Research on the Contact Dynamics of Binary Non-Spherical Particles Based on Hertz Theory

Abstract

In the context of pneumatic transport for bulk grains, pneumatic conveying is a critical technique that safeguards the integrity of the transported grains. The utilization of non-spherical bulk grain particles as the conveyed materials within the transport pipeline emphasizes the importance of analyzing their dynamic behavior within the conduit. A geometric reconstruction technique is applied to represent ellipsoidal bulk grain particles, and leveraging gas–solid coupling theory, a motion model for individual particles in the flow field is developed. By incorporating the Hertz contact model with the equations of motion, a contact dynamics framework for binary non-spherical particles is established, which is subsequently subjected to numerical simulations. A comparative analysis of the physical property parameters of four varieties of bulk grain particles—wheat, rice, soybeans, and corn—illustrates the interrelations among their minimum approach distances, normal and tangential forces, contact forces, total capacities, and the Stokes number. During the pneumatic conveying process, wheat exhibits relatively stable characteristics, thereby minimizing the risk of particle fragmentation, while soybeans and corn demonstrate a higher susceptibility to breakage.