Discrete element modelling of pebble packing in pebble bed reactors

Suikkanen, Heikki; Ritvanen, Jouni; Jalali, Payman; Kyrki-Rajamäki, Riitta

doi:10.1016/j.nucengdes.2014.02.022

Cited by 40 publications

(8 citation statements)

References 20 publications

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“…This coefficient γ can be obtained by matching the TDEM and analytical results in any packing under a certain compressive pressure, which is shown in Fig. (7). This figure indicates that γ depends on the compressive pressure exponentially, which means it drops sharply with pressure by an order of magnitude with little changes within a wide range of pressure increase.…”

Section: Comparison To Analytical Solutionmentioning

confidence: 82%

“…Unlike the continuum description of particulate systems in Eulerian approach, the Lagrangian approach sees individual particles and tracks them every time step. The well-known Lagrangian approach applied extensively in simulations of granular materials is the discrete element method (DEM) that is used to build static packs, Suikkanen et al [7] , or to analyze the dynamics of particle mixtures, Jalali and Hyppanen [8].…”

Section: [K]mentioning

confidence: 99%

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Thermal discrete element method for transient heat conduction in granular packing under compressive forces

Kiani-Oshtorjani

Jalali

2019

International Journal of Heat and Mass Transfer

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A thermal discrete element method is introduced in granular packs. This method is applicable to 3D packing in either static or dynamic states coupled with the ordinary discrete element method code. This method resolves the local heat fluxes and temperature of particles relying on particles conductivity and the deformation of particles at various contact points. Using this method, the time evolution of temperature is studied within packed beds under various compressive forces. Our results match very well with the analytical solution as if the value of the effective conductivity is properly adjusted, which is found to be related to the pressure exponentially. We have also shown that the compression of the granular packing exponentially increases the thermal characteristic time of the bed.

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Section: Comparison To Analytical Solutionmentioning

confidence: 82%

Section: [K]mentioning

confidence: 99%

Thermal discrete element method for transient heat conduction in granular packing under compressive forces

Kiani-Oshtorjani

Jalali

2019

International Journal of Heat and Mass Transfer

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“…9(b) demonstrates computing local packing fraction in a small region, the same principle can be used to define local packing fraction to the level of each particle, by dividing the particle volume by its Voronoi cell volume. This approach has been used to examine local volume fluctuations [69][70][71][72] and dynamic jamming fronts. 73 The use of Voronoi cell faces to identify neighboring particles 74 and the examination of Voronoi cell anisotropy 75,76 have also proven fruitful in the study of granular media and other amorphous systems.…”

Section: Granular Flowsmentioning

confidence: 99%

Voronoi cell analysis: The shapes of particle systems

Lazar,

Lu,

Rycroft

2022

Preprint

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Many physical systems can be studied as collections of particles embedded in space, evolving through deterministic evolution equations. Natural questions arise concerning how to characterize these arrangements -are they ordered or disordered? If they are ordered, how are they ordered and what kinds of defects do they possess? Originally introduced to study problems in pure mathematics, Voronoi tessellations have become a powerful and versatile tool for analyzing countless problems in pure and applied physics. In this paper we explain the basics of Voronoi tessellations and the shapes they produce, and describe how they can be used to study many physical systems.

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“…Comparing to conduction between particles at contact, thermal radiation is much more complicated for numerical computation because of its non-contact and long-range interactions. As well known, the discrete element method (DEM), can be used to simulate the motion of all particles in the particle system [12] and the packing state of particle beds [13], and explore the distinctive features of packing structures [14]. With the aid of space discretization realized by Voronoi tessellation [15], it is also possible to be used for analyzing the heat transfer mechanisms [16][17][18] of mono or multi-sized particles based on the.…”

Section: Introductionmentioning

confidence: 99%