Flow fields and packing states in the discharge flow of noncircular particles

Gui, N., Yang, X., Tu, J., & Jiang, S. (2017). Flow fields and packing states in the discharge flow of noncircular particles—A SIPHPM simulation. Particuology, 35, 10-21. https://doi.org/10.1016/j.partic.2017.01.003

Flow fields and packing states in the discharge flow of noncircular particles—A SIPHPM simulation

Nan Gui ^a, Xingtuan Yang ^a, Jiyuan Tu ^{a b}, Shengyao Jiang ^a *

a Institute of Nuclear and New Energy Technology, Collaborative Innovation Center of Advanced Nuclear Energy Technology, Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education, Tsinghua University, Beijing 100084, China
b School of Engineering, RMIT University, Melbourne VIC 3083, Australia

10.1016/j.partic.2017.01.003

Volume 35, December 2017, Pages 10-21

Received 7 July 2016, Revised 12 August 2016, Accepted 16 January 2017, Available online 23 May 2017, Version of Record 30 November 2017.

E-mail: shengyaojiang@sina.com

Highlights

• Silo width and particle shape dominated the 2D flow pattern of the bed.

• Fluctuation and decay of contact points (CP) indicated intermittent packing in discharge.

• Packing density decreased as polygon side number or base angle increased.

Abstract

Although the discharge flow of spherical materials has been extensively explored, the effect of particle shape on discharge is still poorly understood. The present work explores the two-dimensional discharge flow fields of noncircular particles using the soft-sphere-imbedded pseudo-hard particle model method. Rectangular particles having different aspect ratios (R_a = 1, 1.5, 2–5) and regular polygonal particles having different numbers of sides (N_s = 3–8, 10) are discharged through hopper beds having different orifice widths (D_i = 40, 70.77, 99.13, 125.74, 151.13 mm). The discharge rates of differently shaped particles in different beds are consistent with Beverloo’s relation. Moreover, the flow fields are computed and evaluated to study the effects of R_a, N_s, and D_i on particle discharge. The characteristics of particle–particle connections in the discharge process are evaluated according to the temporal evolution and spatial distribution of the contact points. Additionally, the effect of the initial packing on the discharge profile is investigated. The findings help clarify the discharge of noncircular particles.

Graphical abstract

Keywords

Non-spherical; Discharge flow; Hopper; Particle; Discrete element method

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