Numerical prediction of particle slip velocity in turbulence by CFD-DEM simulation--颗粒学报PARTICUOLOGY

Sun, Z., Yan, X., Wang, L., Li, X., Wang, A., & Zhang, H. (2023). Numerical prediction of particle slip velocity in turbulence by CFD-DEM simulation. Particuology, 80, 170-179. https://doi.org/10.1016/j.partic.2022.11.021

Numerical prediction of particle slip velocity in turbulence by CFD-DEM simulation

Zhixin Sun ^{a 1}, Xiaokang Yan ^{a 1 *}, Lijun Wang ^b *, Xiaoheng Li ^a, Ai Wang ^d, Haijun Zhang ^{a c}

a School of Chemical Engineering, China University of Mining and Technology, Xuzhou, 221116, China
b School of Low-Carbon Energy and Power Engineering, China University of Mining and Technology, Xuzhou, 221116, China
c National Engineering Research Center of Coal Preparation and Purification, China University of Mining and Technology, Xuzhou, 221116, China
d School of Engineering, The University of Newcastle, Callaghan, NSW, 2308, Australia

10.1016/j.partic.2022.11.021

Volume 80, September 2023, Pages 170-179

Received 29 May 2022, Revised 1 November 2022, Accepted 21 November 2022, Available online 14 December 2022, Version of Record 1 March 2023.

E-mail: xk-yan@cumt.edu.cn; wanglijun@cumt.edu.cn

Highlights

• FLUENT-EDEM is applied in solid-liquid flow simulations with fine particles.

• Influence of turbulence, particle density and size on particle slip velocity are analyzed.

• A new equation is proposed between the turbulence intensity and particle slip velocity.

Abstract

Turbulent environment improves the flotation recovery of fine particles by promoting the particle–bubble collision rate, which directly depends on the particle slip velocity. However, the existing slip velocity models are not applicable to fine particles in turbulence. The mechanism of turbulence characteristics and particle properties on the slip velocity of fine particles in turbulence was unclear. In this study, a coupled ANSYS FLUENT and EDEM based on computational fluid dynamics (CFD) and discrete element method (DEM) were used to simulate the slip velocity of fine particles in the approximately homogenous isotropic turbulence, which was excited by the grid. The reliability of the used CFD-DEM simulation method was validated against the slip velocity measured by the particle image velocimetry (PIV) experiments. In particular, the effects of the particle shapes, particle densities, and turbulence intensities on the slip velocity have been investigated with this numerical method. Numerical results show that particle shapes have no significant effect on fine particles between 37 and 225 μm. The slip velocity of the spherical particles increases with the turbulence intensity and particle density. Based on the simulated data, a model which has a correlation coefficient of 0.95 is built by using nonlinear fitting.

Graphical abstract

Keywords

Slip velocity; Fine particles; Turbulence; CFD-DEM

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