Discrete particle simulation of particulate systems: Theoretical developments

Zhu, Haiping; Zhou, Zongyan; Yang, Runyu; Yu, Aibing

doi:10.1016/j.ces.2006.12.089

Cited by 1,569 publications

(739 citation statements)

References 176 publications

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“…Due to a discrete description of the solid phase, constitutive relations are omitted, and therefore, leads to a better understanding of the fundamentals. This was also concluded by Zhu et al (2007Zhu et al ( , 2008) during a review on particulate flows modelled with the CCDM approach. Based on this approach Sheng et al (2013) investigated into the micro-scale heat transfer of packed beds and micro-fibrous entrapped catalysts and concluded that the thermal resistance of the contact points account for more than 90 % of the total resistance.…”

Section: Introductionmentioning

confidence: 99%

“…However, current CCDM approaches should be extended to a truly multi-phase flow behaviour as opposed to the Volume-of-Fluid method and the multi-phase mixture model stated by Sheng (2013). Furthermore, particle shapes other than spherical geometries have to be taken into account to meet engineering needs according to Zhu et al (2007Zhu et al ( , 2008. This efforts should ideally be complemented by poly-disperse particle systems as employed by Peters and Dziugys (2011).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

An Integral Approach to Multi-physics Application for Packed Bed Reactors

Peters

Besseron

Estupinan

et al. 2014

Computer Aided Chemical Engineering

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A large number of engineering applications involve granular material or a particulate phase in combination with a gaseous or liquid phase. Predominant applications are as diverse as pharmaceutical industry e.g. drug production, agriculture food and processing industry, mining, construction and agricultural machinery, metals manufacturing, energy production and systems biology. Common to all these application is that they cover a large spectrum of length scales ranging from inner particle length scales to global dimensions of the reactor. In order to describe the processes and their interaction accurately, tailored algorithms are required for prediction and analysis. The current numerical approach of the Extended Discrete Element Method (XDEM) is based on an Eulerian-Lagrange coupling. For this purpose the solid phase consisting of individual particles is treated by the Lagrange method that describes both the dynamic state i.e. position and orientation of each particle in space and time and its thermodynamic state e.g. internal temperature and species distribution. The flow of gas in the void space between the particles is predicted by traditional and well-proven Computational Fluid Dynamics (CFD) taking into account heat and mass transfer between the particles and the surrounding gas phase. Hence, the entire process represented by the sum of all particle processes in conjunction with fluid dynamics. The afore-mentioned numerical concept was applied to predict pyrolysis of a packed bed of wood particles in a cylindrical reactor. A comparison of predicted results with experimental data show good agreement. Hence, the numerical concept is able to resolve a large range of length scales for solid reaction engineering. An analysis of detailed results helps to uncover the underlying physics of the process, and thus, allows for an improved design and operation conditions.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

An Integral Approach to Multi-physics Application for Packed Bed Reactors

Peters

Besseron

Estupinan

et al. 2014

Computer Aided Chemical Engineering

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“…They attributed that the charge acquisition of the powder initially occurs primarily during the contact between the particles and the cylinder. However, it is extremely difficult to obtain detailed information from each particle in the dynamic system experimentally [15][16][17]. Therefore, the discrete element method coupled with computational fluid dynamics (DEM-CFD) has been widely used to explore the physical and mechanical behaviours of each individual particle and subsequent bulk properties of the particle system.…”

Section: Introductionmentioning

confidence: 99%

Numerical analysis of contact electrification of non-spherical particles in a rotating drum

Chen

Adams

2015

Powder Technology

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Contact electrification is generally referred to as the charge transfer process between particles during collisions. The transferred charge can be accumulated on the surface of the particles especially for insulating materials with irregular shapes, which can lead to a non-uniform charge distribution and eventually affects the charge accumulation process. In this study, in order to investigate the influence of the particle shape on contact electrification, a sphere-tree multi-sphere method and a contact electrification model are implemented into the discrete element method (DEM) to model the charging process of irregular particles in a rotating drum. Irregular particles with various Sauter mean diameters but the same maximum diameter and equivalent volume diameters are considered. The charge distribution and accumulation on the particles are investigated. It is found that the charge transfer originates from the contact between the particle and the drum due to the contact potential difference and ζ Presently with Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, CB3 0FS, UK * Corresponding author: Tel: 01483683506. Email: c.y.wu@surrey.ac.uk 2 initially takes place primarily at the region near the wall of the drum. The charge eventually propagates to the entire granular bed. The charge of the particles increases exponentially to an equilibrium value. For particles with the same maximum diameter, a larger charging coefficient is obtained for the particles with smaller Sauter mean diameters and sphericities, which lead to a faster charge accumulation, while for particles with the same equivalent volume diameter and fill ratio, similar charging coefficients are observed. A non-uniform intra-particle charge distribution is induced on each individual multi-sphere particle.

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“…A variety of continuum fluid codes, coupled with discrete-element-method (DEM) particles, are utilized by researchers around the world in commercial codes as well as codes developed by university researchers. An overview of these methods can be found in Zhu et al (2007). The algorithm relies on the parameterizations of drag terms similar to the Ergun equation (Ergun 1952) for static packed beds, or the Wen-Yu equation for moving beds (Wen and Yu 1966).…”

Section: Introductionmentioning

confidence: 99%

“…Clearly, it's difficult to have one single simulation method that can cover all length and time scales. Currently there is a hierarchy of methods that can cover different length and time scales with different levels of details (Zhu et al 2007).…”

Section: Introductionmentioning

confidence: 99%

Mesoscale simulations of particulate flows with parallel distributed Lagrange multiplier technique

2011

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Fluid particulate flows are common phenomena in nature and industry. Modeling of such flows at micro and macro levels as well establishing relationships between these approaches are needed to understand properties of the particulate matter. We propose a computational technique based on the direct numerical simulation of the particulate flows. The numerical method is based on the distributed Lagrange multiplier technique following the ideas of Glowinski et al. (1999). Each particle is explicitly resolved on an Eulerian grid as a separate domain, using solid volume fractions. The fluid equations are solved through the entire computational domain, however, Lagrange multiplier constrains are applied inside the particle domain such that the fluid within any volume associated with a solid particle moves as an incompressible rigid body. Mutual forces for the fluid-particle interactions are internal to the system. Particles interact with the fluid via fluid dynamic equations, resulting in implicit fluid-rigid-body coupling relations that produce realistic fluid flow around the particles (i.e., no-slip boundary conditions). The particle-particle interactions are implemented using explicit force-displacement interactions for frictional inelastic particles similar to the DEM method of Cundall et al. (1979) with some modifications using a volume of an overlapping region as an input to the contact forces. The method is flexible enough to handle arbitrary particle shapes and size distributions. A parallel implementation of the method is based on the SAMRAI (Structured Adaptive Mesh Refinement Application Infrastructure) library, which allows handling of large amounts of rigid particles and enables local grid refinement. Accuracy and convergence of the presented method has been tested against known solutions for a falling sphere as well as by examining fluid flows through stationary particle beds (periodic and cubic packing). To evaluate code performance and validate particle contact physics algorithm, we performed simulations of a representative experiment conducted at the University of California at Berkley for pebble flow through a narrow opening.

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Discrete particle simulation of particulate systems: Theoretical developments

Cited by 1,569 publications

References 176 publications

An Integral Approach to Multi-physics Application for Packed Bed Reactors

An Integral Approach to Multi-physics Application for Packed Bed Reactors

Numerical analysis of contact electrification of non-spherical particles in a rotating drum

Mesoscale simulations of particulate flows with parallel distributed Lagrange multiplier technique

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