Prof. Sida Liu
Jiangxi Key Laboratory for Simulation and Modelling of Particulate Systems
Jiangxi University of Science and Technology
Dr. Sida Liu completed his PhD from Monash University in Australia in 2015 and served as a postdoctoral researcher at Monash University in the same year. In 2017, he joined Jiangsu Industrial Technology Research Institute of Industrial Process Simulation and Optimization as a project manager, and the executive deputy general manager of the incubated enterprise of the Institute in the same year, In 2020, he joined Jiangxi Aobo Particle Technology Research Institute as the chief researcher. In 2021, he joined Jiangxi University of Science and Technology. Dr. Liu is engaged in the development and application of complex multi-scale multiphase flow models using advanced computing methods in the field of particle science.
Title: DEM Study of Particle Shape Effects on Hopper Flow in a Cylindrical Bin
Abstract: Hopper flow characteristics are significantly affected by particle shape. In this report, ellipsoidal particles which can represent a large number of shapes are used to investigate the shape effect on granular flow in a cylindrical hopper. Numerical experiments are conducted by use of discrete element method, with its validity verified by comparison with the results from physical experiments. The results indicate that particle shape can make a significant effect on the flow pattern. In particular, the increase of deviation from sphere can decrease mixed region adjacent to the side wall, and increase the stagnant zone at the bottom corner. It may also lead to decreased wall stress. The results show that due to the better flowabilities, spheres exert higher maximum stress on walls than ellipsoids. Wall stress for ellipsoids approaches a constant value quickly. It is also found that the wall stress distribution is not affected much by orifice size, but solid bed height. Furthermore, particle shape has a significant effect on the discharge rate. Spheres of unity aspect ratio have the highest flow rate, and the lower or higher aspect ratio, the smaller the flow rate. Based on the numerical results, the an attempt is made to characterize the two parameters of wall friction coefficient μ and the lateral stress ratio KA in Jessen-Walker-Walters theory, indicating that both μ and KA vary with aspect ratio of ellipsoids. The assumption of the constant μ and KA may bring significant error in the wall stress prediction. The Beverloo equation is also modified, where parameters C and k in the equation are respectively formulated as a function of aspect ratio.