Study on a semi-resolved CFD-DEM method for rod-like particles in a gas-solid fluidized bed--颗粒学报PARTICUOLOGY

He, L., Liu, Z., & Zhao, Y. (2024). Study on a semi-resolved CFD-DEM method for rod-like particles in a gas-solid fluidized bed. Particuology, 87, 20-36. https://doi.org/10.1016/j.partic.2023.07.014

Study on a semi-resolved CFD-DEM method for rod-like particles in a gas-solid fluidized bed

Liping He ^a, Zhengxian Liu ^a *, Yongzhi Zhao ^b

a Department of Mechanics, School of Mechanical Engineering, Tianjin University, Tianjin, 300350, China
b Institute of Process Equipment, College of Energy Engineering, Zhejiang University, Hangzhou, 310027, China

10.1016/j.partic.2023.07.014

Volume 87, April 2024, Pages 20-36

Received 19 June 2023, Revised 14 July 2023, Accepted 20 July 2023, Available online 3 August 2023, Version of Record 5 August 2023.

E-mail: zxliu@tju.edu.cn

Highlights

• Using minimum distance between fluid grid and particle boundary to evaluate effect of particle's drag force.

• Optimized semi-resolved CFD-DEM method is verified by a fluidized bed of rod-like particles.

• Semi-resolved CFD-DEM coupling algorithm exhibits mesh independence of fluid grid scale.

Abstract

Based on a semi-resolved CFD-DEM coupling method, this study proposed a method that uses the minimum distance between the fluid grid and the particle boundary as a reference value to determine the degree of influence of the target fluid grid on the particle's drag force. A fluidized bed of rod-like particles was chosen as a typical case to investigate the effect of different fluid grid scales on various fluidized bed characteristic parameters. The calculation performance of the semi-resolved and unresolved CFD-DEM coupling algorithm on key fluidized bed characteristic parameters such as average pressure drop, particle frequency distribution with bed height, and particle orientation distribution were compared. It was found that the semi-resolved CFD-DEM coupling algorithm gradually obtained results with higher consistency with decreasing fluid grid scale for key parameters such as particle frequency distribution with bed height, particle orientation distribution, and time-history mixing index, exhibiting a phenomenon similar to grid independence in fluid simulation. By comparing with experimental results, it was verified that the semi-resolved CFD-DEM coupling algorithm can be applied to simulate multi-granular gas-solid systems with fluid grid scales equivalent to particle scales. This algorithm solves the limitation of fluid grid scale in the unresolved CFD-DEM coupling framework and improves the grid adaptability of the CFD-DEM coupling simulation algorithm.

Graphical abstract

Keywords

CFD-DEM; Semi-resolved method; Fluid–solid flow; Non-spherical particle; Fluidized bed

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