A study of influence of gravity on bulk behaviour of particulate solid--颗粒学报PARTICUOLOGY

Chung, Y.-C., & Ooi, J. Y. (2008). A study of influence of gravity on bulk behaviour of particulate solid. Particuology, 6(6), 467–474. https://doi.org/10.1016/j.partic.2008.07.017

A study of influence of gravity on bulk behaviour of particulate solid

Yun-Chi Chung ^a, Jin Yeam Ooi ^b *

a Department of Civil and Environmental Engineering, Nanya Institute of Technology, 414, Sec. 3, Chung-Shang E. Road, Chungli, Taoyuan, Taiwan, China
b Institute for Infrastructure & Environment, School of Engineering & Electronics, University of Edinburgh, Edinburgh EH9 3JL, UK

10.1016/j.partic.2008.07.017

Volume 6, Issue 6, December 2008, Pages 467-474

Received 27 April 2008, Accepted 15 July 2008, Available online 18 November 2008.

E-mail: J.Ooi@ed.ac.uk

Highlights

Abstract

This paper examines the influence of gravity on the bulk responses of a granular solid. The loading scenarios in this study include confined compression, rod penetration into a granular medium and discharging through an orifice. Similar loading and flow conditions are likely to be encountered in the stress and deformation regimes that regoliths are subjected to in extraterrestrial exploration activities including in situ resource utilisation processes. Both spherical and non-spherical particles were studied using the discrete element method (DEM). Whilst DEM is increasingly used to model granular solids, careful validations of the simulation outcomes are rather rare. Thus in addition to exploring the effect of gravity, this paper also compares DEM simulations with experiments under terrestrial condition to verify whether DEM can produce satisfactory predictions. The terrestrial experiments were conducted with great care and simulated closely using DEM. The key mechanical and geometrical properties for the particles were measured in laboratory tests for use in the DEM simulations. A series of DEM computations were then performed under reduced gravity to simulate these experiments under extraterrestrial environment. It was found that gravity has no noticeable effect on the force transmission in the confined compression case; the loading gradient in the rod penetration is linearly proportional to the gravity; the mass flow rate in silo discharge is proportional to square root of the gravity and the angle of repose increases with reducing gravity. These findings are in agreement with expectation and existing scientific evidence.

Graphical abstract

Keywords

Extraterrestrial; Particulate assembly; Confined compression; Rod penetration; Silo discharge; Discrete element method; Gravity effect

文章导读