Particle scale modelling of solid flow characteristics in liquid fluidizations of ellipsoidal particles

Particle shape is one of the most important parameters that can cause significant changes of flow characteristics in liquid fluidized beds, which however has not been well studied in the past. In this work, CFD-DEM approach is used to investigate the hydrodynamics of ellipsoidal particles in liquid...

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Bibliographic Details
Published in:Powder technology 2018-10, Vol.338, p.677-691
Main Authors: Abbaszadeh Molaei, E., Yu, A.B., Zhou, Z.Y.
Format: Article
Language:English
Subjects:
Aspect ratio
Computational fluid dynamics
Discrete element method
Drag
Ellipsoids
Entrainment
Flow characteristics
Flow velocity
Fluid dynamics
Fluid flow
Fluid mechanics
Fluidized beds
Freeboard
Hydrodynamics
Liquid fluidization
Nonuniformity
Particle shape
Porosity
Pressure
Shape effects
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Summary:Particle shape is one of the most important parameters that can cause significant changes of flow characteristics in liquid fluidized beds, which however has not been well studied in the past. In this work, CFD-DEM approach is used to investigate the hydrodynamics of ellipsoidal particles in liquid fluidizations. The non-uniformity distributions of pressure gradient and porosity with bed height are successfully captured for ellipsoids at high liquid superficial velocities, consistent with those reported in literature. The results also show that ellipsoids intend to enter the freeboard region and entrainment may occur. Disc-shape particles expand more significantly than spherical and elongated particles. The force analysis indicates that with particle aspect ratio deviating from 1.0, the drag force acting on ellipsoids increases while pressure gradient force reduces. Particle shape effects shown above are closely related to particle orientations which can significantly affect particle-fluid interaction force and particle terminal velocities. [Display omitted] •Liquid fluidization of ellipsoidal particles is investigated by CFD-DEM.•Oblate particles have low terminal velocities and tend to display entrainment phenomenon.•Non-uniform distributions of pressure gradient and porosity are observed for ellipsoids.•Ellipsoids have significant bed expansion which is quantified by Richardson and Zaki's equation.•Force distributions are affected by particle shape due to the orientation of ellipsoids.
ISSN:0032-5910
1873-328X
DOI:10.1016/j.powtec.2018.07.063