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Journal of Materials Science & Technology 2005年第5期21卷 753-758页

作者： H.B.DongDepartment of Engineering, University of Leicester, Leicester, LE1 7RH, UK Department of Engineering University of Leicester

A numerical model Alloy/M has been applied to investigate the microsegregation in Al-4.45 wt pct Cu alloy. The calculated data were compared with the experimental measurements for samples solidified at different cooling rates. Discrepancies in solute concentration occur between the experimental observations and calculated results. Reasons for the discrepancies were discussed, and the effect of dendrite joining at a later stage of solidification on the microsegregation was investigated. Calculations that have included this effect showed a better fit with experimental results.

关键词： Microsegregation numerical modelling Dendrite growth Aluminium alloy Dendrite joining

numerical modelling of non-ideal detonation in ANFO explosives applying Wood-Kirkwood theory coupled with EXPLO5 thermochemical code

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Defence Technology（防务技术） 2021年第5期17卷 1740-1752页

作者： Barbara Stimac Vinko Skrlec Mario Dobrilovic Muhamed Suceska Faculty of Mining Geology and Petroleum EngineeringUniversity of ZagrebPierottijeva 610000ZagrebCroatia

Ammonium nitrate and fuel oil(ANFO)based explosive is a classic example of non-ideal high *** detonation is characterized by a strong dependence of detonation parameters on explosive charge diameter,presence and characteristics of confinement,as well as incomplete consumption of explosive at the sonic *** this work we propose a detonation model based on the Wood-Kirkwood(WK)theory coupled with the thermochemical code EXPLO5 and supplemented with reaction rate *** objective is to analyze the validity of the model for highly non-ideal ANFO explosives,with emphasis on effect of reaction rate *** was found that both single-step and two-step pressure-based models can be calibrated to reproduce experimental detonation velocity-charge radius data of ANFO at radii significantly above the failure radius(*** D/D_(id)>~0.6).Single-step pressure-based model,with the pressure exponent equal to 1.4,proved to be the most accurate,even in the vicinity of the failure *** impact of the rate models is most evident on temporal(and spatial)distribution of flow parameters in detonation driving zone,especially when it comes to the conversion and width of detonation driving zone.

关键词： ANFO Non-ideal detonation Reaction rate model numerical modelling EXPLO5

numerical modelling of Nitrogen Thermal Effects Produced by the Negative DC Corona Discharge

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Plasma Science and Technology 2010年第2期12卷 208-211页

作者： A.K.FEROUANI M.LEMERINI S.BELHOUR Laboratory of Theoretical Physics University Abou Bakr Belkaid University of Boumerdes Faculty of Science Department of Physics University of Constantine Faculty of Science Department of Physics

In this work, we simulate numerically the thermal effects in nitrogen at atmospheric pressure caused by a negative corona DC discharge of low current. A mathematical function that simulates the injection of the thermal transfer in gas is proposed. The simulated discharge is of a negative point to plane mass type, with an interelectrode distance of 12 mm and a symmetry about the axis of discharge. The spatial and temporal evolution of neutrals is analyzed based upon the equations of continuity, momentum and energy in a cylindrical geometry. For the geometry of the system, the FCT （flux corrected transport） procedure was adopted.

关键词： negative-corona discharge FCT method numerical modelling transport equations

numerical modelling of riverbed grain size stratigraphic evolution

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International Journal of Sediment Research 2014年第3期29卷 329-343页

作者： Peng HU Zhi-xian CAO Gareth PENDER Huai-han LIU Ocean College Zhejiang University State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Institute for Infrastructure and Environment Heriot-Watt University Institute for Infrastructure and Environment Heriot-Watt University State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Yangtze Waterway Planning Design and Research Institute

For several decades,quantification of riverbed grain size stratigraphic evolution has been based upon the active layer formulation(ALF),which unfortunately involves considerable *** it is the sediment exchange across the bed surface that directly affects the riverbed stratigraphy,it has been assumed in the ALF that the sediment fraction at the lower interface of the active layer is a linear function of the sediment fraction in the *** it is proposed that the sediment fraction of the sediment exchange flux is used directly in estimating the sediment fraction at the lower surface of the active *** with the size-specific mass conservation for riverbed sediment,the modified approach is referred to as the surface-based formulation(SBF).When incorporated into a coupled non-capacity modelling framework for fluvial processes,the SBF leads to results that agree as well or better than those using ALF with laboratory and field *** is illustrated for typical cases featuring bed aggradation and degradation due to graded bed-load sediment *** experiments on graded sediment transport by unsteady flows are warranted for further testing the modified formulation.

关键词： Bedload Riverbed grain size stratigraphy Active layer formulation Surface-based formulation numerical modelling

numerical modelling of strength and energy release characteristics of pillar-scale coal mass

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第5期11卷 935-943页

作者： Onur Vardar Chengguo Zhang Ismet Canbulat Bruce Hebblewhite School of Minerals and Energy Resources Engineering.University of New South Wales

Coal burst is a manifestation of rapid energy release,which is considered as one of the most critical operational hazards in underground coal *** study numerically investigates the effects of discontinuities on the strength and energy release characteristics of coal mass samples under uniaxial *** universal distinct element code(UDEC)was used to model pillar-scale coal mass samples that were represented by an assembly of triangular deformable blocks,and pre-existing discontinuities such as bedding planes and cleats were also included in the *** shows that cleat spacing can have a significant impact on compressive strength and energy release,with both strength and energy release(magnitude and rate)reducing as the number of cleats was *** work is one of the first attempts to numerically model and quantify the energy release which occurs during the failure of pillar-scale coal mass samples with varying cleat *** insights from the numerical modelling can help to understand the possible energy release mechanisms and associated coal burst potential in changing coal cleat conditions.

关键词： Coal burst Coal clearing Energy release Distinct element method(DEM) numerical modelling

numerical modelling of channel migration with application to laboratory rivers

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International Journal of Sediment Research 2015年第1期30卷 13-27页

作者： Jian SUN Bin-liang LIN Hong-wei KUANG State key Laboratory of Hydroscience and Engineering Department of Hydraulic EngineeringTsinghua University State Key Laboratory of Hydroscience and Engineering Department of Hydraulic EngineeringTsinghua University Cardiff School of Engineering CardiffWales CF243AAUK Changjiang Waterway Planning Design and Research Institute

The paper presents the development of a morphological model and its application to experimental model *** model takes into account the key processes of channel migration,including bed deformation,bank failure and wetting and *** flows in bends play an important role in lateral sediment transport,which further affects channel migration.A new formula has been derived to predict the near-bed secondary flow speed,in which the magnitude of the speed is linked to the lateral water level *** only non-cohesive sediment is considered in the current study,the bank failure is modelled based on the concept of submerged angle of *** wetting and drying process is modelled using an existing *** between the numerical model predictions and experimental observations for various discharges have been *** is found that the model predicted channel planform and cross-sectional shapes agree generally well with the laboratory observations.A scenario analysis is also carried out to investigate the impact of secondary flow on the channel migration *** shows that if the effect of secondary flow is ignored,the channel size in the lateral direction will be seriously underestimated.

关键词： Channel migration numerical modelling Sediment transport Secondary flow

numerical modelling of structural controls on fluid flow and mineralization

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Geoscience Frontiers 2011年第3期2卷 449-461页

作者： J.Robinson P.M.Schaubs CSIRO Earth Sciences and Resource Engineering PO Box 1130BentleyWA 6102Australia

This paper presents the results of a set of numerical models focussing on structural controls on hydrothermal mineralization. We first give an overview of natural phenomena of structurally-controlled ore formation and the background theory and mechanisms for such controls. We then provide the results of a group of simple 2D numerical models validated through comparison with Cu-vein structure observed near the Shilu Copper deposit （Yangchun, Guangdong Province, China） and finally a case study of 3D numerical modelling applied to the Hodgkinson Province in North Queensland （Australia）. Two modelling approaches, discrete deformation modelling and continuum coupled deformation and fluid flow modelling, are involved. The 2D model-derived patterns are remarkably consistent with the Cu-vein structure from the Shilu Copper deposit, and show that both modelling approaches can realistically simulate the mechanical behaviours of shear and dilatant fractures. The continuum coupled deformation and fluid flow model indicates that pattern of the Cu- veins near the Shilu deposit is the result of shear strain localization, development of dilation and fluid focussing into the dilatant fracture segments. The 3D case-study models （with deformation and fluid flow coupling） on the Hodgkinson Province generated a number of potential gold mineralization

关键词： Structural control Dilation Fluid flow Mineralization numerical modelling Shilu Cu-deposit Hodgkinson Province

3-D numerical modelling of Domino failure of hard rock pillars in Fetr6 Chromite Mine, Iran, and comparison with empirical methods

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Journal of Central South University 2013年第2期20卷 541-549页

作者： S.Dehghan K.Shahriar P.Maarefvand K.Goshtasbi Department of Mining Engineering Science and Research BranchIslamic Azad University Department of Mining and Metallurgical Engineering Amirkabir University of Technology Department of Mining Engineering Tarbiat Modares University

Fetr6 is an underground mine using the stope-and-pillar mining method. As there was some evidence regarding pillar failure in this mine, improving works such as roof support and replacing existing pillars with concrete pillars (CP) were carried out. During the construction of the second CP, in the space between the remaining pillars, one of the pillars failed leading to the progressive failure of other pillars until 4 000 m 2 of mine had collapsed within a few minutes. In this work, this phenomenon is described by applying both numerical and empirical methods and the respective results are compared. The results of numerical modelling are found to be closer to the actual condition than those of the empirical method. Also, a width-to-height (W/H) ratio less than 1, an inadequate support system and the absence of a detailed program for pillar recovery are shown to be the most important causes of the Domino failure in this mine.

关键词： hard rock Domino failure numerical modelling empirical method stope pillar extraction ratio W/H ratio

Physical and numerical modelling of the Severn Barrage

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Science China(Technological Sciences) 2014年第8期57卷 1471-1481页

作者： JAMES Brammer ROGER A Falconer CHRISTOPHER Ellis REZA Ahmadian Cardiff University the ParadeCardiff CF24 3AAUK School of Engineering Cardiff Universitythe ParadeCardiff CF24 3AAUK Arup 4 Pierhead StreetCardiff CF10 4QPUK

The Severn Estuary has one of the largest tidal ranges in the world and has long been the subject of consideration for tidal energy *** plans to build a tidal barrage across the estuary have existed in various forms since the 1920s,the 1989Severn Tidal Power Group(STPG)proposal is commonly referred to as the original Severn *** UK government abandoned this ebb generation scheme as a public investment project in ***,plans to build a two-way generation scheme were more recently put forward by a private consortium,namely Hafren *** assess the impact that a barrage would have on the hydro-environment in the estuary a number of numerical modelling studies have previously been conducted for the STPG *** this design has now been superseded by the Hafren Power proposal,new studies have been conducted to investigate the impact of a two-way *** this study the hydro-environmental impacts of both ebb-only and two-way schemes were assessed using physical and numerical modelling *** model barrages were constructed and testing was carried out using a physical model of the Severn Estuary,located in the hydraulics laboratory at Cardiff University.A depth integrated numerical model,namely DIVAST,was applied to the physical model geometry and modifications were made to simulate the effects of the barrage *** numerical model predictions showed good agreement with the corresponding laboratory *** results were consistent with conclusions from previous studies,relating to the ebb-only *** included an increase in the minimum water levels upstream of the barrage,a reduction in the mean water levels downstream of the barrage and a general reduction in tidal *** a two-way scheme changes in the tidal elevations and velocities depended on the exact operating conditions of the *** was found that with no starting head the tidal regime was similar to the natural state,with little change in the e

关键词： Severn Barrage numerical modelling physical modelling ebb generation two-way generation

Overhanging rock slope by design:An integrated approach using rock mass strength characterisation,large-scale numerical modelling and limit equilibrium methods

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第1期10卷 72-90页

作者： Paul Schlotfeldt Davide Elmo Brad Panton Golder Associates Ltd. VancouverCanada NBK Institute of Mining The University of British ColumbiaVancouverCanada

Overhanging rock slopes(steeper than 90°) are typically avoided in rock engineering design, particularly where the scale of the slope exceeds the scale of fracturing present in the rock mass. This paper highlights an integrated approach of designing overhanging rock slopes where the relative dimensions of the slope exceed the scale of fracturing and the rock mass failure needs to be considered rather than kinematic release of individual blocks. The key to the method is a simplified limit equilibrium(LE) tool that was used for the support design and analysis of a multi-faceted overhanging rock slope. The overhanging slopes required complex geometries with constantly changing orientations. The overhanging rock varied in height from 30 m to 66 m. Geomechanical modelling combined with discrete fracture network(DFN)representation of the rock mass was used to validate the rock mass strength assumptions and the failure mechanism assumed in the LE model. The advantage of the simplified LE method is that buttress and support design iterations(along with sensitivity analysis of design parameters) can be completed for various cross-sections along the proposed overhanging rock sections in an efficient manner, compared to the more time-intensive, sophisticated methods that were used for the initial validation. The method described presents the development of this design tool and assumptions made for a specific overhanging rock slope design. Other locations will have different geological conditions that can control the potential behaviour of rock slopes, however, the approach presented can be applied as a general guiding design principle for overhanging rock cut slope.

关键词： Rock slopes Discrete fracture network(DFN) Rock mass strength characterisation numerical modelling Limit equilibrium(LE) methods