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Journal articleElbeshausen D, Wuennemann K, Collins GS, 2009, , ICARUS, Vol: 204, Pages: 716-731, ISSN: 0019-1035
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- Citations: 173
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Journal articlePiggott MD, Farrell PE, Wilson CR, et al., 2009, , PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, Vol: 367, Pages: 4591-4611, ISSN: 1364-503X
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- Citations: 74
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Journal articleBland PA, Jackson MD, Coker RF, et al., 2009, , EARTH AND PLANETARY SCIENCE LETTERS, Vol: 287, Pages: 559-568, ISSN: 0012-821X
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- Citations: 133
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Journal articleFang F, Pain CC, Navon IM, et al., 2009, , International Journal for Numerical Methods in Fluids, Vol: 63, Pages: 185-206, ISSN: 1097-0363
The approach for designing an error measure to guide an adaptive meshing algorithm proposed in Power et al. (Ocean Modell. 2006; 15:3-38) is extended to use a POD adjoint-based method, thus facilitating efficient primal and adjoint integration in time. The aim is to obtain a new mesh that can adequately resolve all the fields at all time levels, with optimal (w.r.t. the functional) efficiency. The goal-based method solves both the primal and adjoint equations to form the overall error norms, in the form of a metric tensor. The tetrahedral elements are then optimized so that they have unit size in Riemannian space defined with respect to the metric tensor.This is the first attempt to use POD to estimate an anisotropic error measure. The metric tensor field can be used to direct anisotropic mesh adaptivity. The resulting mesh is optimized to efficiently represent the solution fields over a given time period. The calculation of the error measures is carried out in the reduced space. The POD approach facilitates efficient integration backwards in time and yields the sensitivity analysis necessary for the goal-based error estimates. The accuracy of both the primal and adjoint-reduced models is thus optimized (through the use of anisotropic mesh adaptivity). In addition, the functional for optimizing meshes has been designed to be consistent with that for 4D Var data assimilation.
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Journal articleNeethling SJ, Cilliers JJ, 2009, , INTERNATIONAL JOURNAL OF MINERAL PROCESSING, Vol: 93, Pages: 141-148, ISSN: 0301-7516
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- Citations: 102
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Journal articleKenkmann T, Collins GS, Wittmann A, et al., 2009, , Geological Society of America Special Paper, Vol: 458, Pages: 571-586
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Journal articleAvdis A, Lardeau S, Leschziner M, 2009, , FLOW TURBULENCE AND COMBUSTION, Vol: 83, Pages: 343-370, ISSN: 1386-6184
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- Citations: 48
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Journal articleGetsinger A, Rushmer T, Jackson MD, et al., 2009, , JOURNAL OF PETROLOGY, Vol: 50, Pages: 1935-1954, ISSN: 0022-3530
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- Citations: 31
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Conference paperLatham J-P, Xiang J, 2009,
Application of the finite-discrete element method to dynamic stress development in armour units and armour layers
, Coasts, Marine Structures and Breakwaters 2009, Adapting to Change -
Journal articleJackson MD, Hampson GJ, Sech RP, 2009, , AAPG BULLETIN, Vol: 93, Pages: 1183-1208, ISSN: 0149-1423
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- Citations: 61
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Journal articleSech RP, Jackson MD, Hampson GJ, 2009, , AAPG Bulletin, Vol: 93, Pages: 1155-1181, ISSN: 0149-1423
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Journal articleHopcroft PO, Gallagher K, Pain CC, 2009, , GEOPHYSICAL JOURNAL INTERNATIONAL, Vol: 178, Pages: 651-666, ISSN: 0956-540X
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- Citations: 23
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Conference paperDavison TM, Collins GS, Ciesla F, 2009,
Quantifying heating in porous planetesimal collisions
, 72nd Annual Meeting of the Meteoritical-Society, Publisher: Meteoritical Society, Pages: A58-A58, ISSN: 1086-9379 -
Conference paperCiesla FJ, Davison TM, Collins GS, 2009,
Cooling of porous planetesimals after impacts: Implications for the thermal evolution of primitive bodies
, 72nd Annual Meeting of the Meteoritical-Society, Publisher: Meteoritical Society, Pages: A51-A51, ISSN: 1086-9379 -
Conference paperCollins GS, Wuennemann K, 2009,
NUMERICAL MODELING OF IMPACT EJECTION PROCESSES IN POROUS GEOLOGIC MATERIALS
, 72nd Annual Meeting of the Meteoritical-Society, Publisher: METEORITICAL SOC, Pages: A53-A53, ISSN: 1086-9379- Cite
- Citations: 2
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Journal articleHopcroft PO, Gallagher K, Pain CC, et al., 2009, , JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE, Vol: 114, ISSN: 0148-0227
An understanding of the way that ground surface temperatures have changed with time contributes to our knowledge of past climate change. One approach that has been used to achieve this is to relate deviations in borehole temperature depth profiles to past ground surface temperatures. This paper describes a new computationally efficient reduced order approach that eliminates problems associated with very localised borehole terrain affects. This approach expands upon a world-leading expertise in reduced order modelling methods and facilitates the use of a much broader range of geothermal data to be used for palaeoclimate reconstruction purposes.
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Conference paperCiesla FJ, Collins GS, Davison TM, et al., 2009,
Collisions among porous planetesimals and the water content of planetary embryos
, 19th Annual VM Goldschmidt Conference, Publisher: Elsevier, Pages: A227-A227, ISSN: 0016-7037 -
Conference paperMerton SR, Pain CC, Smedley-Stevenson RP, et al., 2009,
A non-linear optimal discontinuous Petrov-Galerkin method for stabilising the solution of the transport equation
, International Conference on Mathematics, Computational Methods & Reactor Physics -
Journal articleWang Y, Neethling SJ, 2009, , COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS, Vol: 339, Pages: 73-81, ISSN: 0927-7757
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- Citations: 38
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Journal articleXiang J, 2009, , POWDER TECHNOLOGY, Vol: 191, Pages: 280-293, ISSN: 0032-5910
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- Citations: 8
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Journal articleFang F, Pain CC, Navon IM, et al., 2009, , INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Vol: 59, Pages: 827-851
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Journal articleSlingo J, Bates K, Nikiforakis N, et al., 2009, , PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, Vol: 367, Pages: 815-831, ISSN: 1364-503X
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- Citations: 51
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Journal articleHam DA, Farrell PE, Gorman GJ, et al., 2009, , Geoscientific Model Development, Vol: 2, Pages: 33-42
The interfaces by which users specify the scenarios to be simulated by scientific computer models are frequently primitive, under-documented and ad-hoc text files which make using the model in question difficult and error-prone and significantly increase the development cost of the model. In this paper, we present a model-independent system, Spud, which formalises the specification of model input formats in terms of formal grammars. This is combined with an automated graphical user interface which guides users to create valid model inputs based on the grammar provided, and a generic options reading module, libspud, which minimises the development cost of adding model options. Together, this provides a user friendly, well documented, self validating user interface which is applicable to a wide range of scientific models and which minimises the developer input required to maintain and extend the model interface.
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Journal articleLatham JP, Mindel J, Xiang J, et al., 2009, , Geomechanics and Geoengineering, Vol: 4, Pages: 39-53, ISSN: 1748-6033
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Journal articleAgung A, Lathouwers D, van der Hagen THJJ, et al., 2009, , NUCLEAR TECHNOLOGY, Vol: 165, Pages: 133-144, ISSN: 0029-5450
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Conference paperBrito-Parada PR, Pain CC, Neethling SJ, et al., 2009,
3D Drainage of Liquid in Froths for Modelling Flotation Cells
, Flotation'09 -
Conference paperBrito-Parada PR, Pain CC, Neethling SJ, et al., 2009,
Modelling the drainage of liquid in froth flotation cells and columns
, Procemin -
Journal articlePain CC, Gomes JLMA, Eaton MD, et al., 2009,
Modelling of Granular Materials in the FETCH Coupled Criticality Code
, Transactions of the American Nuclear Society, Vol: 100, Pages: 331-334, ISSN: 0003-018X -
Conference paperBrito-Parada PR, Pain CC, Neethling SJ, et al., 2009,
Three-dimensional drainage of liquid in froths for modelling flotation cells
, Minerals Research in UK Universities -
Journal articleHam DA, Farrell PE, Gorman GJ, et al., 2009, , GEOSCIENTIFIC MODEL DEVELOPMENT, Vol: 2, Pages: 33-42, ISSN: 1991-959X
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- Citations: 11
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Conference paperGorman GJ, Pain CC, Piggott MD, et al., 2009,
Interleaved parallel tetrahedral mesh optimisation and dynamic load-balancing
, Brussels, Belgium, the fourth International Conference on Adaptive Modeling and Simulation -
Journal articleJaafar MZ, Vinogradov J, Jackson MD, et al., 2009,
Measurements of streaming potential for downhole monitoring in intelligent wells
, SPE, Vol: 120460 -
Journal articleHalgedahl SL, Jarrard RD, Brett CE, et al., 2009, , Palaeogeography, Palaeoclimatology, Palaeoecology, Vol: 277, Pages: 34-56, ISSN: 0031-0182
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Journal articleJaafar MZ, Vinogradov J, Jackson MD, 2009, , Geophysical Research Letters
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Conference paperLatham JP, Xiang J, 2009,
Application of the finite-dicrete element method to dynamic stress development in armour units and armour layers
, Coasts, Marine Structures and Breakwaters 2009, Publisher: Thomas Telford -
Journal articleGarcia X, Lateef A, Blunt M, et al., 2009, , Physics Review E, Vol: 80
We study through numerical simulations the dependence of the hydraulic permeability of granular materials on the particle shape and the grain size distribution. Several models of sand are constructed by simulating the settling under gravity of the grains; the friction coefficient is varied to construct packs of different porosity. The size distribution and shapes of the grains mimic real sands. Fluid flow is simulated in the resulting packs using a finite element method and the permeability of the packs is successfully compared with available experimental data. Packs of nonspherical particles are less permeable than sphere packs of the same porosity. Our results indicate that the details of grain shape and size distribution have only a small effect on the permeabilty of the systems studied.
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Conference paperXiang J, Mindel J, Latham JP, et al., 2009,
A combined FEM and DEM Fluids-Particulates model of waves interacting with granular media
, Fifth International Conference on Coastal Structures, Publisher: World Scientific Publishing Co. Pte. Ltd, Pages: 1441-1452 -
Journal articleChristeson GL, Collins GS, Morgan JV, et al., 2009, , Earth and Planetary Science Letters, Vol: 284, Pages: 249-257, ISSN: 0012-821X
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Journal articleFarrell PE, Piggott MD, Pain CC, et al., 2009, , Computer Methods in Applied Mechanics and Engineering, Vol: 198, Pages: 2632-2642
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Journal articleXiang J, Munjiza A, Latham J-P, 2009, , International Journal for Numerical Methods in Engineering, Vol: 79, Pages: 946-978
In the past, the combined finite-discrete element was mostly based on linear tetrahedral finite elements. Locking problems associated with this element can seriously degrade the accuracy of their simulations. In this work an efficient ten-noded quadratic element is developed in a format suitable for the combined finite-discrete element method (FEMDEM). The so-called F-bar approach is used to relax volumetric locking and an explicit finite element analysis is employed. A thorough validation of the numerical method is presented including five static and four dynamic examples with different loading, boundary conditions, and materials. The advantages of the new higher-order tetrahedral element are illustrated when brought together with contact detection and contact interaction capability within a new fully 3D FEMDEM formulation. An application comparing stresses generated within two drop experiments involving different unit specimens called Vcross and VRcross is shown. The Vcross and VRcross units of 3.5 × 104kg show very different stress generation implying different survivability upon collision with a deformable floor. The test case shows the FEMDEM method has the capability to tackle the dynamics of complex-shaped geometries and massive multi-body granular systems typical of concrete armour and rock armour layers.
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Journal articleHam DA, Pain CC, Hanert E, et al., 2009, , Ocean Modelling, Vol: 28, ISSN: 1463-5003
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Journal articleCotter CJ, Ham DA, Pain CC, 2009, , Ocean Modelling, Vol: 26, Pages: 86-90, ISSN: 1463-5003
We introduce a mixed discontinuous/continuous finite element pair for ocean modelling, with continuous quadratic layer thickness and discontinuous velocity. We investigate the finite element pair applied to the linear shallow-water equations on an f-plane. The element pair has the property that all geostrophically balanced states which strongly satisfy the boundary conditions have discrete divergence equal to exactly zero and hence are exactly steady states of the discretised equations. This means that the finite element pair has excellent geostrophic balance properties. We also show that the element pair applied to the non-rotating linear shallow-water equations does not have any spurious small eigenvalues. We illustrate these properties using numerical tests and provide convergence calculations which show that the numerical solutions have errors which decay quadratically with element edge length for both velocity and layer thickness.
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Journal articleFang F, Pain CC, Navon IM, et al., 2009, , Int. J. Numer. Meth. Fluids, Vol: 60, Pages: 709-732
This paper presents a novel approach for inverting a complex ocean model via a proper orthogonal decomposition. The inversion is achieved through the construction of an adjoint model and used to assimilate data in a similar manner to that used in weather forecasting. This is an incredibly important capability for an ocean model, however it is both complex to construct and also can be computationally expensive. The approach proposed here addresses both of these important issues by constructing an efficient and easy to compute adjoint directly from the reduced order model. The approach is demonstrated by inverting for initial conditions in an ocean gyre simulation. The methodology proposed here led directly to the award of a £1M EPSRC grant (EP/I00405X) to develop reduced order and adjoint models for coastal oceanography. Cited 11 times.
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Conference paperMindel J, Collins G, Latham JP, et al., 2009,
Towards a numerical wave simulator using the two-fluid interface tracking approach combined with a novel ALE scheme
, Fifth International Conference on Coastal Structures, Publisher: World Scientific Publishing Co. Pte, Pages: 1465-1476 -
Journal articleBrett CE, Allison PA, DeSantis MK, et al., 2009, , Palaeogeography, Palaeoclimatology, Palaeoecology, Vol: 277, Pages: 9-33, ISSN: 0031-0182
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Journal articleFang F, Pain CC, Navon IM, et al., 2009, , Ocean Modelling, Vol: 28, Pages: 127-136, ISSN: 1463-5003
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Journal articleGarcia X, Latham J-P, Xiang J, et al., 2009,
A clustered overlapping sphere algorithm to represent real particles in discrete element modelling
, Geotechnique -
Journal articleGuises R, Xiang J, Munjiza A, et al., 2009, , Granular Matter, Vol: 11, Pages: 281-292
The packing of granular particles is investigated using a combined finite-discrete element approach. One of the aims of this paper is to present an application of a recently improved numerical simulation technique for deformable granular material with arbitrary shapes. Our study is focused on the influence of the effect of the particle shape on (1) the emergent properties of a granular pack (packing density,coordination number, force distribution), and on (2) the spatial distribution of the stress.Aset of simulations that mimick the sedimentation process is carried out, with varying input parameters, such as contact friction and particle shape. It is shown that the eccentricity of the particles not only significantly influences the final density of the pack but also the distribution of the stress and the contact forces. The presence of surface friction increases the amount of disorder within the granular system. Stress heterogeneities and force chain patterns propagate through the particles more efficiently than for the frictionless systems. The results also suggest that for the monodisperse systems investigated the coordination number is one of the factors that controls the distribution of the stress within a granular medium.
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Conference paperLatham JP, Mindel J, Guises R, et al., 2009,
Coupled FEM-DEM and CFD for coastal structures: application to armour stability and breakage
, Proceedings of the Fifth International Conference on Coastal Structures, Publisher: World Scientific Publishing Co. Pte. Ltd, Pages: 1453-1464 -
Journal articleXiang J, McGlinchey D, Latham J-P, 2009,
An investigation of segregation and mixing in dense phase pneumatic conveying
, Granular Matter
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