Investigation of particle–wall interaction in a pseudo-2D fluidized bed using CFD-DEM simulations--颗粒学报PARTICUOLOGY

Li, T., Zhang, Y., & Hernández-Jiménez, F. (2016). Investigation of particle–wall interaction in a pseudo-2D fluidized bed using CFD-DEM simulations. Particuology, 25, 10-22. https://doi.org/10.1016/j.partic.2015.06.001

Investigation of particle–wall interaction in a pseudo-2D fluidized bed using CFD-DEM simulations

Tingwen Li ^{a b *}, Yongmin Zhang ^c, Fernando Hernández-Jiménez ^d

a National Energy Technology Laboratory, Morgantown, WV 26507, USA
b AECOM, Morgantown, WV 26507, USA
c State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China
d Universidad Carlos III of Madrid, Department of Thermal and Fluid Engineering, Av. de la Universidad, 30, 28911 Leganés, Madrid, Spain

10.1016/j.partic.2015.06.001

Volume 25, April 2016, Pages 10-22

Received 2 April 2015, Revised 15 May 2015, Accepted 18 June 2015, Available online 11 September 2015, Version of Record 18 February 2016.

E-mail: tingwen.li@contr.netl.doe.gov; litingwen@gmail.com

Highlights

• CFD-DEM simulations were conducted for a pseudo-2D fluidized bed.

• Detailed particle–wall interactions were analyzed.

• There existed strong anisotropic flow behavior in the system.

• An effective friction coefficient was derived for particle-wall flow interaction.

Abstract

We report on discrete element method simulations of a pseudo-two-dimensional (pseudo-2D) fluidized bed to investigate particle–wall interactions. Detailed information on macroscopic flow field variables, including solids pressure, granular temperature, and normal and tangential wall stresses are analyzed. The normal wall stress differs from the solids pressure because of the strong anisotropic flow behavior in the pseudo-2D system. A simple linear relationship exists between normal wall stress and solids pressure. In addition, an effective friction coefficient can be derived to characterize particle–wall flow interaction after evaluating the normal and tangential wall stresses. The effects of inter-particle and particle–wall friction coefficients are evaluated. Strong anisotropic flow behavior in the pseudo-2D system needs to be considered to validate the two-fluid model where the boundary condition is usually developed based on an isotropic assumption. The conclusion has been confirmed by simulation with different particle stiffnesses. Assumptions in the newly developed model for 2D simulation are further examined against the discrete element method simulation.

Graphical abstract

Keywords

Gas–solid flow; Fluidized bed; Computational fluid dynamics; Discrete element method; Particle–wall interaction; Two-dimensional flow

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