CFD-DEM simulation of Small-Scale Challenge Problem 1 with EMMS bubble-based structure-dependent drag coefficient10.1016/j.partic.2020.09.007--颗粒学报PARTICUOLOGY

Musango, L., John, S., & Lloyd, M. (2021). CFD-DEM simulation of Small-Scale Challenge Problem 1 with EMMS bubble-based structure-dependent drag coefficient. Particuology, 55, 48-61. https://doi.org/10.1016/j.partic.2020.09.007

CFD-DEM simulation of Small-Scale Challenge Problem 1 with EMMS bubble-based structure-dependent drag coefficient10.1016/j.partic.2020.09.007

Musango Lungu ^*, John Siame, Lloyd Mukosha

Multiphase Flow Research Group, Chemical Engineering Department, School of Mines and Mineral Sciences, Copperbelt University, Kitwe 10101, Zambia

10.1016/j.partic.2020.09.007

Volume 55, April 2021, Pages 48-61

Received 1 July 2020, Revised 12 August 2020, Accepted 1 September 2020, Available online 27 October 2020, Version of Record 3 February 2021.

E-mail: musango.lungu@cbu.ac.zm

Highlights

• Bubble-based structure-dependent drag coefficient is integrated in MFIX-DEM.

• CFD-DEM simulations are compared using several drag coefficients.

• CFD-DEM model is validated against NETL SSCP1 pressure-drop and particle velocity data.

Abstract

In this study, the energy minimization multi-scale (EMMS)/Bubbling model is coupled with the computational fluid dynamics/discrete element method (CFD-DEM) model via a structure-dependent drag coefficient to simulate the National Energy Technology Laboratory (NETL) small-scale challenge problem using the open-source multiphase flow code MFIX. The numerical predictions are compared against particle velocity measurements obtained from high-speed particle image velocimetry (HSPIV) and differential pressure measurements. The drag-reduction effect of the EMMS bubble-based drag coefficient is observed to significantly improve predictions of the horizontal particle velocity and granular temperature when compared to several other drag coefficients tested; however, the vertical particle velocity and pressure fluctuation characteristic predictions are degraded. The drag-reduction effect is characterized by a reduction in the sizes of slugs or voids, as identified through spectral decomposition of the pressure fluctuations. Overall, this study shows great promise in employing drag coefficients, developed via multi-scale approaches (such as the EMMS paradigm), in CFD-DEM models.

Graphical abstract

Keywords

CFD-DEM; Drag model; EMMS/Bubbling model; Fluidization; Multi-scale

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