Validation of a discrete element model using magnetic resonance measurements--颗粒学报PARTICUOLOGY

Müller, C. R., Scott, S. A., Holland, D. J., Clarke, B. C., Sederman, A. J., Dennis, J. S., & Gladden, L. F. (2009). Validation of a discrete element model using magnetic resonance measurements. Particuology, 7(4), 297–306. https://doi.org/10.1016/j.partic.2009.04.002

Validation of a discrete element model using magnetic resonance measurements

Christoph R. Müller^*, Stuart A. Scott, Daniel J. Holland, Belinda C. Clarke, Andrew J. Sederman, John S. Dennis, Lynn F. Gladden

Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA, United Kingdom

10.1016/j.partic.2009.04.002

Volume 7, Issue 4, August 2009, Pages 297-306

Received 17 November 2008, Accepted 15 April 2009, Available online 9 July 2009.

E-mail: cm433@cam.ac.uk

Highlights

Abstract

The discrete element model (DEM) is a very promising modelling strategy for two-phase granular systems. However, owing to a lack of experimental measurements, validation of numerical simulations of two-phase granular systems is still an important issue. In this study, a small two-dimensional gas-fluidized bed was simulated using a discrete element model. The dimensions of the simulated bed were 44 mm × 10 mm × 120 mm and the fluidized particles had a diameter d_p = 1.2 mm and density ρ_p = 1000 kg/m³. The comparison between DEM simulations and experiments are performed on the basis of time-averaged voidage maps. The drag-law of Beetstra et al. [Beetstra, R., van der Hoef, M. A., & Kuipers, J. A. M. (2007b). Drag force of intermediate Reynolds number flow past mono- and bidispersed arrays of spheres. AIChE Journal, 53, 489–501] seems to give the best results. The simulations are fairly insensitive to the coefficient of restitution and the coefficient of friction as long as some route of energy dissipation during particle–particle and particle–wall contact is provided. Changing the boundary condition of the gas phase at the side-walls from zero-slip to full-slip does not affect the simulation results. Care is to be taken that the cell sizes are chosen so that a reasonable number of particles can be found in a fluid cell.

Graphical abstract

Keywords

Discrete element modelling; Magnetic resonance imaging; Voidage; Gas-fluidized beds

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