Elsevier

Powder Technology

Volume 395, January 2022, Pages 400-411
Powder Technology

Infiltration and resuspension of dilute particle suspensions in micro cavity flow

https://doi.org/10.1016/j.powtec.2021.09.066Get rights and content
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Highlights

  • Sedimentation of particle suspensions in a cavity flow is numerically analysed.

  • The effects of the flow inertia and the configuration of the cavity are quantified.

  • A dimensionless trap number is proposed to well describe the trap efficiency.

  • Three distinctive regimes were identified based on the value of trap number.

Abstract

Sedimentation of particle suspensions in a channel flow into a cavity is analysed numerically using a lattice Boltzmann method coupled with a discrete element method. The work focuses on the entrapment of particles inside a confined cavity and the particle dynamics after entrapment. A close examination of the particle motions reveals three distinct dynamic behaviours: i) resuspension, ii) circulation in the central vortex and iii) deposition to the rear edge of the cavity. The effects of fluid inertia, particle density and cavity size on the infiltration and resuspension behaviours are systematically investigated. The results show that decreasing the Reynolds number, and increasing the length and depth of the cavity all lead to an increase in the trap efficiency. Three distinctive regimes with respect to the trap efficiency were then identified by deriving an empirical dimensionless trap number Tp: a resuspension regime when Tp < 1, a continuous circulating regime when 1 ≤ Tp ≤ 2.5, and a fully trapped regime when Tp > 2.5.

Keywords

Sedimentation
Cavity flow
Lattice Boltzmann method
Discrete element method
Trap efficiency

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