Discrete particle simulation of mixed sand transport--颗粒学报PARTICUOLOGY

Xiao, F., Guo, L., Li, D., & Wang, Y. (2012). Discrete particle simulation of mixed sand transport. Particuology, 10(2), 221–228. https://doi.org/10.1016/j.partic.2011.10.004

Discrete particle simulation of mixed sand transport

Fengjun Xiao, Liejin Guo^*, Debiao Li, Yueshe Wang

State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an 710049, China

10.1016/j.partic.2011.10.004

Volume 10, Issue 2, April 2012, Pages 221-228

Received 29 July 2011, Revised 13 October 2011, Accepted 21 October 2011, Available online 9 February 2012.

E-mail: lj-guo@mail.xjtu.edu.cn

Highlights

► Effects of wall characteristics, size distribution of sand particles and boundary layer depth on distributions of sand mass flux and particle velocity are simulated.

► The simulated mean horizontal velocity for all particle size groups well fits experimental data.

► Wall characteristics greatly affects particle to wall collision and makes the flat bed similar to a Gobi surface and the rough bed similar to a sandy surface.

Abstract

An Eulerian/Lagrangian numerical simulation is performed on mixed sand transport. Volume averaged Navier–Stokes equations are solved to calculate gas motion, and particle motion is calculated using Newton's equation, involving a hard sphere model to describe particle-to-particle and particle-to-wall collisions. The influence of wall characteristics, size distribution of sand particles and boundary layer depth on vertical distribution of sand mass flux and particle mean horizontal velocity is analyzed, suggesting that all these three factors affect sand transport at different levels. In all cases, for small size groups, sand mass flux first increases with height and then decreases while for large size groups, it decreases exponentially with height and for middle size groups the behavior is in-between. The mean horizontal velocity for all size groups well fits experimental data, that is, increasing logarithmically with height in the middle height region. Wall characteristics greatly affects particle to wall collision and makes the flat bed similar to a Gobi surface and the rough bed similar to a sandy surface. Particle size distribution largely affects the sand mass flux and the highest heights they can reach especially for larger particles.

Graphical abstract

Keywords

Mixed sand transport; Hard sphere model; Sand mass flux; Particle horizontal mean velocity

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