Discrete element method study on hopper discharge behaviors of binary mixtures of nonspherical particles

Abstract

This study is aimed at unveiling the influence of binary mixtures of nonspherical particles on hopper discharge behavior, which remains poorly understood. The discrete element method (DEM) is employed to simulate seven particle types with aspect ratios between 0 and 2 (namely, a sphere, two ellipsoids, two cylinders, and two cuboids) with the same volume. Seven monodisperse systems and twelve binary‐shape mixtures are assessed. For the monodisperse systems, particle shape is the dominant factor dictating discharge rate, compared to other factors like aspect ratio, preferential orientation, and packing. Regarding the binary‐shape mixtures, the discharge rates are similar for all twelve mixtures, reflecting a surprising lack of shape effects, which in turn means the negligible impact of solid volume fraction, aspect ratio, and segregation extent. Moreover, collision force is generally negatively correlated with discharge rate.

An investigation into the impact of particle properties on flow behaviors

“…Specifically, residual particles are observed for the hoppers containing the cylinders and cuboids, while the hoppers with the spheres and ellipsoids are discharged fully. This agrees with our previous study on monodisperse and binary mixture systems [197], and indicates increased difficulty in discharging angular particles. Figure 7.12 displays the residual particles of the cylinders and cuboids for the monodisperse and narrower PSD (𝜎/𝜇 = 10% and 20%) systems.…”

“…The spheres and cuboids exhibit the greatest and least discharge rates, respectively, which agrees with our previous study [197].…”

“…This substantiates the important effect of both particle shape and PSD width on particle packing. which is consistent with the results for the monodisperse and binary mixture systems in our previous study [197]. Secondly, among the different particle shapes, jamming occurs at the narrowest PSD width for the cuboid at 𝜎/𝜇 = 20%, compared to that at 30% for the spheres, ellipsoids and cylinders.…”

DEM Modelling of Segregation in Granular Materials: A Review

“…Parameters from literature. Many DEM studies on segregation have taken either all or merely a selection of the parameters from the literature (Asachi et al, 2021;Chibwe et al, 2020;Cliff et al, 2021;Hong et al, 2021;Ketterhagen et al, 2007Ketterhagen et al, , 2009Ketterhagen and Hancock, 2010;Kou et al, 2013Kou et al, , 2015Kou et al, , 2018Kou et al, , 2019Liao et al, 2023;Mandal and Khakhar, 2019;Tian et al, 2022;Wu et al, 2013;Xu et al, 2018bXu et al, , 2021You et al, 2016;Yu et al, 2018;Yu and Saxén, 2010, 2012Zhang et al, 2021;Zhao and Chew, 2020a). This approach has the same shortcoming as the previous group, since the parameters are obtained from resources that have not conducted calibration.…”

“…Two types of experiments have been carried out (cf. Mathematical (Ketterhagen et al, 2008;Ketterhagen and Hancock, 2010;Yu and Saxén, 2013;Zhao and Chew, 2020a) First-hand experimental results…”