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Article
Publication date: 25 May 2012

C.R. Leonardi, D.R.J. Owen and Y.T. Feng

The purpose of this paper is to present a novel computational framework capable of simulating the block cave phenomenon of fines migration in two dimensions. Fines migration is…

Abstract

Purpose

The purpose of this paper is to present a novel computational framework capable of simulating the block cave phenomenon of fines migration in two dimensions. Fines migration is characterised by the faster movement of fine and often low‐grade material towards the draw point in comparison to larger, blocky material. A greater understanding of the kinematic behaviour of fines and ore within the cave during draw is integral to the solution of this problem.

Design/methodology/approach

The lattice Boltzmann method (LBM) is employed in a nonlinear form to represent the fines as a continuum, and it is coupled to the discrete element method (DEM) which is used to represent large blocks. The issues relevant to this approach, such as fluid‐solid interaction, the synchronisation of explicit schemes, and the characterisation of a bulk material as a non‐Newtonian fluid are discussed.

Findings

Results of the 2D simulations reveal migration trends for the geometries, material properties and operational sequences analysed. By executing an extensive programme of numerical experiments the influence of these and other relevant block cave factors on the migration of fines could be isolated.

Originality/value

To the authors' knowledge, this is the first time the LBM has been used to simulate the flow of bulk materials. The non‐Newtonian LBM‐DEM framework is also a novel approach to the investigation of fines migration, which until now has been limited to scale models, cellular automata or pure DEM simulations. The results of the 2D migration analyses highlight the potential for this novel approach to be applied in an industrial context and also encourage the extension of the framework to 3D.

Article
Publication date: 25 May 2012

C.R. Leonardi, D.R.J. Owen and Y.T. Feng

The purpose of this paper is to present a novel computational framework based on the lattice Boltzmann method (LBM) and discrete element method (DEM) capable of simulating fines…

Abstract

Purpose

The purpose of this paper is to present a novel computational framework based on the lattice Boltzmann method (LBM) and discrete element method (DEM) capable of simulating fines migration in three dimensions. Fines migration occurs in a block cave mine, and is characterised by the faster movement of fine and often low‐grade material towards the draw point in comparison to larger, blocky material.

Design/methodology/approach

This study builds on the foundations and applications outlined in a companion paper, in which the non‐Newtonian LBM‐DEM framework is defined and applied in 2D simulations. Issues relevant to the extension to 3D, such as spatial discretisation, fluid boundary conditions and the definition of synthetic bulk material parameters using a power law model, are discussed.

Findings

The results of the 3D DEM percolation replication showed that migration is predominantly limited to within the draw zone, and that the use of a low‐cohesion material model resulted in a greater amount of fines migration. The draw sensitivity investigation undertaken with the two bell partial block cave analysis did not show a significant difference in the amount of migration, despite the two draw strategies being deliberately chosen to result in isolated and interactive draw of material.

Originality/value

Along with the companion paper, this paper presents a novel application of the developed non‐Newtonian LBM‐DEM framework in the investigation of fines migration, which until now has been limited to scale models, cellular automata or pure DEM simulations. The results highlight the potential for this approach to be applied in an industrial context, and indicate a number of potential avenues for further research.

Article
Publication date: 1 February 1992

KEVIN M. O'CONNOR and CHARLES H. DOWDING

To simulate the kinematics associated with mining‐induced subsidence in a blocky rock mass, a hybrid rigid block model was developed by combining a small displacement code with a…

Abstract

To simulate the kinematics associated with mining‐induced subsidence in a blocky rock mass, a hybrid rigid block model was developed by combining a small displacement code with a large displacement code. Gravity was applied to a rigid block mesh using an implicit formulation and the equilibrium displacements are then used as initial conditions for an explicit analysis in which excavation of a longwall mine panel and subsequent subsidence was simulated. A parameter study was performed to evaluate the influence of rigid block contact stiffness, vertical joint density, and contact roughness on mining‐induced strata movements for comparison with previously obtained field measurements. The best agreement between measured and calculated displacements was obtained when a relatively low stiffness value was maintained constant for all contacts. A surprising result was that neither increasing the density of vertical joints nor reducing the rigid block contact roughness improved the agreement between measured and simulated displacements.

Details

Engineering Computations, vol. 9 no. 2
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 22 February 2013

Paul W. Cleary, Raymond C.Z. Cohen, Simon M. Harrison, Matthew D. Sinnott, Mahesh Prakash and Stuart Mead

The purpose of this paper is to show how simulation of the flow of particulates and fluids using discrete element modelling (DEM) and smoothed particle dynamics (SPH) particle…

663

Abstract

Purpose

The purpose of this paper is to show how simulation of the flow of particulates and fluids using discrete element modelling (DEM) and smoothed particle dynamics (SPH) particle methods, offer opportunities for better understanding the dynamics of flow processes.

Design/methodology/approach

DEM and SPH methods are demonstrated in a broad range of computationally‐demanding applications including comminution, biomedical, geophysical extreme flow events (risk/disaster modelling), eating of food by humans and elite water‐based sports.

Findings

DEM is ideally suited to predicting industrial and geophysical applications where collisions between particles are the dominant physics. SPH is highly suited to multi‐physics fluid flow applications in industrial, biophysical and geophysical applications. The advantages and disadvantages of these particle methods are discussed.

Research limitations/implications

Research results are limited by the numerical resolution that can currently be afforded.

Practical implications

The paper demonstrates the use of particle‐based computational methods in a series of high value applications. Enterprises that share interests in these applications will benefit in their product and service development by adopting these methods.

Social implications

The ability to model disasters provides governments and companies with the opportunity and obligation to use these to render knowable disasters which were previously considered unknowable. The ability to predict the breakdown of food during eating opens up opportunities for the design of superior performing foods with lower salt, sugar and fat that can directly contribute to improved health outcomes and can influence government food regulatory policy.

Originality/value

The paper extends the scale and range of modelling of particle methods for demanding leading‐edge problems, of practical interest in engineering and applied sciences.

Details

Engineering Computations, vol. 30 no. 2
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 1 July 1955

The ESSO RESEARCH AND ENGINEERING COMPANY IS NOW CONSTRUCTING A RADIATION LABORATORY at Linden, New Jersey. This new centre will, according to Eger V. Murphree, president of the…

Abstract

The ESSO RESEARCH AND ENGINEERING COMPANY IS NOW CONSTRUCTING A RADIATION LABORATORY at Linden, New Jersey. This new centre will, according to Eger V. Murphree, president of the company and a member of the Atomic Energy Commission's General Advisory Committee, be devoted to applying “the vast potential of atomic energy to the petroleum industry”. It is claimed that it will be the first privately financed radiation laboratory of its type, and that it should make possible an intensive research programme for the oil industry.

Details

Industrial Lubrication and Tribology, vol. 7 no. 7
Type: Research Article
ISSN: 0036-8792

Article
Publication date: 1 November 1942

F.R. Shanley

AT Lockheed (Ref. 18) the double‐acting press has been used toad vantage in this work, as it permits the part to be held at the edges while the punchforms it, thereby building up…

Abstract

AT Lockheed (Ref. 18) the double‐acting press has been used toad vantage in this work, as it permits the part to be held at the edges while the punchforms it, thereby building up the desired tensile stress. This is illustrated by Fig. 32. The same general effect may be obtained in the single‐acting press with rubber punch by the use of special concave blocks in which the sheet is clamped at the edges by means of beaded plates or other devices. Mechanical stretching machines are also available for this type of work. These methods are generally not as satisfactory as the double‐acting press, however, as the latter permits greater control over the edge restraint conditions.

Details

Aircraft Engineering and Aerospace Technology, vol. 14 no. 11
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 1 July 1955

E.G. CURPHEY

ADDITIVES today are important ingredients in lubricating compositions whose efficiency they enhance by an improvement in certain desired characteristics. The inclusion of such…

Abstract

ADDITIVES today are important ingredients in lubricating compositions whose efficiency they enhance by an improvement in certain desired characteristics. The inclusion of such substances in lubricating mixtures has therefore occupied the attention of both the engineer and chemist.

Details

Industrial Lubrication and Tribology, vol. 7 no. 7
Type: Research Article
ISSN: 0036-8792

Article
Publication date: 5 April 2019

Robert Bogue

This paper aims to provide an insight into the future for disaster relief (DR) and search and rescue (SAR) robots by considering research activities which seek to address…

Abstract

Purpose

This paper aims to provide an insight into the future for disaster relief (DR) and search and rescue (SAR) robots by considering research activities which seek to address real-world applications and by identifying key user requirements and development priorities.

Design/methodology/approach

Following a short introduction, this first provides a brief overview of the use of robots in DR and SAR and gives examples of organisations promoting their use. This is followed by details of development programmes aimed at meeting users’ requirements. Specific needs are identified and considered in detail and were derived from both the literature and through discussions with users. This paper concludes with a tabulated summary of key development priorities.

Findings

This study shows that several collaborative research programmes aim to address real DR and SAR applications, with robots being tested in simulated disaster scenarios. A number of key user requirements and development priorities are identified for aerial, ground and marine robots.

Originality/value

By identifying a number of specific requirements, this paper will assist in focussing research and development activities towards real users’ needs.

Details

Industrial Robot: the international journal of robotics research and application, vol. 46 no. 2
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 1 June 1991

N.P. Obokoh

A flood disaster at the University of Port Harcourt Library,Nigeria, is reported. The rescue action taken to salvage water damagedmaterials is described. The problems encountered…

Abstract

A flood disaster at the University of Port Harcourt Library, Nigeria, is reported. The rescue action taken to salvage water damaged materials is described. The problems encountered during the rescue operations are highlighted and the need to prepare disaster rescue plans and make library staff aware of rescue options available is emphasised.

Details

Library Review, vol. 40 no. 6
Type: Research Article
ISSN: 0024-2535

Keywords

Article
Publication date: 1 February 1992

PETER A. CUNDALL and ROGER D. HART

Discrete element methods are numerical procedures for simulating the complete behaviour of systems of discrete, interacting bodies. Three important aspects of discrete element…

2569

Abstract

Discrete element methods are numerical procedures for simulating the complete behaviour of systems of discrete, interacting bodies. Three important aspects of discrete element programs are examined: (1) the representation of contacts; (2) the representation of solid material; and (3) the scheme used to detect and revise the set of contacts. A proposal is made to define what constitutes a discrete element program, and four classes of such programs are described: the distinct element method, modal methods, discontinuous deformation analysis and the momentum‐exchange method. Several applications and examples are presented, and a list is given of suggestions for future developments.

Details

Engineering Computations, vol. 9 no. 2
Type: Research Article
ISSN: 0264-4401

Keywords

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