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Journal of Hydrodynamics 2022年第4期34卷 700-711页

作者： Yuan Li Chi Zhang Shan-hang Chi Yun-han Yang Jian Shi Ti-ti Sui State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai UniversityNanjing 210024China College of Harbour Coastal and Offshore EngineeringHohai UniversityNanjing 210024China State Key Laboratory of Estuarine and Coastal Research East China Normal UniversityShanghai 200241China

Physical model experiments on sandbar migration are widely conducted in the wave flume to reveal its hydro-sediment dynamic *** an appropriate scale relation is an important part of designing a laboratory ***,evaluating the scale effect is complicated since it is impractical to design wave flume experiments based on strict geometry scales derived from the prototype beach or other laboratory ***,a process-based numerical model is used to test the Dean and Shields similitudes by comparing sandbar migration and sediment transport in different undistorted model scales using natural *** numerical model provides excellent predictions for both offshore sandbar migration on a real-world beach and onshore sandbar migration in the wave *** with previous studies,sandbar offshore migration and suspended sediment transport are similar when the Dean similitude is *** onshore migration and bedload transport can be well reproduced only if the Shields similitude is *** previous laboratory experiments of sandbar migration generally used the Dean similitude,it is found that the Shields similitude is effective and indispensable for modelling sandbar onshore migration,which will be underestimated if the Dean similitude is only *** scale relation cannot be used simultaneously for modelling both onshore and offshore sandbar migration in physical models.

关键词： Coastal sandbar migration sediment transport scale relations numerical modelling

numerical modellings of Properties of the Summer Quasi-Stationary Circulation Systems and Their Monthly Variations

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Advances in Atmospheric Sciences 1994年第4期11卷 399-407页

作者：钱永甫钱云王谦谦 Department of Atmospheric Sciences Nanjing University Nanjing 210093 Nanjing Institute of Meteorology Nanjing 210044

An ocean-atmosphere and land-air coupled numerical model system is used to study the basic properties and the monthly time variations of the summer quasi-stationary circulation systems. It is found that either at the upper or at the lower levels of the atmosphere, the circulation patterns have a two-wave structure in the zonal direction at the mid and high latitudes of the Northern Hemisphere. Such a structure of circulation is totally matchable to that of the land-sea distribution there. It is proved, hence, that the land-sea distributive pattern is the fundamental cause for the summer quasi-stationary circulation pattern. The topography in the globe is the secondary factor for circulation systems. The circulation centres of the quasi-stationary systems are always located in certain areas due to the thermodynamic contrast between land and *** the time evolutions of the circulation systems it is seen that the change is larger at the beginning period of the time integration, it is because of using the zonally averaged mean fields as the initial values of the model. As long as the basic simulated pattern of circulations reaches the state similar to that of the real climatic fields resulting from the coeffects of the land-sea distribution and the topography, the circulation systems modelled will change slowly and tend to a quasi-stationary state. Therefore, the time integration does not need to last for a very long time, if the purpose of numerical modellings is to test sensitivities of some factors influencing the climate, 20 model days may be enough for sensitive experiments.

关键词： Quasi-stationary circulation systems numerical modelling

numerical anisotropic fracture mechanics modelling in crystalline rock

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Numerical anisotropic fracture mechanics modelling in crysta...

Air pumping for alleviation of heavy smog in Beijing

Harmonising Rock Engineering and the Environment—12th ISRM International Congress on Rock Mechanics

作者： T.Siren K.Kemppainen M.Rinne Posiva Oy EurajokiFinland Fracom Ltd KirkkonummiFinland

＜正＞1 INTRODUCTION 1.1 Fracture propagation code（FRACOD） Most numerical methods for rock engineering are based on methods that cannot genuinely describe the fracture initiation and *** propagation code（FRACOD） is a two-dimensional Displacement Discontinuity Method（DDM） computer code that was designed to simulate fracture initiation and propagation. The code development was started in early nineties by Shen ＆ Stephansson（1993）.The FRACOD code is based on

关键词： numerical modelling rock stress nuclear repository case studies

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Science China Earth Sciences 2018年第7期61卷 973-979页

作者： Yaping SHAO Sven ULBRICH Dehui CHEN Institute for Geophysics and Meteorology Department of GeosciencesUniversity of CologneCologne 50923Germany China Meteorological Administration Beijing 100081China

Beijing often suffers under heavy *** such events which occur mostly in autumn and winter,people are desperate for fresh *** formation of heavy smog is due to foremost human induced air pollution,but geographic and meteorological conditions,especially below a surface inversion,play an important *** propose to destroy the inversion by pumping air from above the inversion layer to the surface layer to alleviate the severity of the *** long-term air quality improvement depends on the reduction of air pollution emission,air pumping may provide relief in the interim for the Beijing *** estimate that an air pumping at a rate 2×10~7m^3s^(–1)can lead to significantly improved air quality in Beijing,due to(1)direct clean air input;(2)increased instability and vertical mixing and(3)a positive radiation-mixing *** pumping requires an energy input of 10 GW,comparable with the energy consumption in Beijing for air conditioning in *** propose to use wind energy from Inner Mongolia for the pumping,which has currently an installed wind energy capacity of 70GW.

关键词： Beijing air quality Air pumping numerical modelling Inversion

numerical MODELING PURIFICATION PERFORMANCE OF POT TEST

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Journal of Hydrodynamics 2010年第5期22卷 709-718页

作者： DAI Yu WANG De-guan ZHANG Jin-feng LUAN Qing-hua Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes of Ministry of Education Hohai University Nanjing 210098 China College of Mechanics and Materials Science Hohai University Nanjing 210098 China College of Environmental Hohai University Nanjing 210098 China College of Water Conservancy and Hydropower Hebei University of Engineering Handan 056021 China

A three-dimensional mathematical model was developed to simulate the pollutant removal efficiency of the soil and plants in the pot test. The advection, dispersion, diffusion, adsorption, biochemical reaction and plant uptake processes were taken into account in the model. The three-dimensional modified Richards equation was used in simulating flow field. The mass balance law was employed in deriving the equation for pollutant transport, where the diffusion and dispersion were described with the Fick-type law, the adsorption was macroscopically expressed as form isotherm, and the bio-chemical degradation process was assumed to follow the Monod kinetics. The mathematical model was descretized by the finite element numerical method. In the pot test, the hydraulic loading was assumed to have the intermittent pattern simulating the rainfall duration and the occurrence of frequency, and the concentrations of pollutants in the influent and effluent were measured. The computed overall removal rates for the CODCr and TN in four cases are in the range of 90.62% - 95.43% and 85.01% - 96.46%, respectively. The differences between the computed and tested overall removal rates for the CODCr and TN are smaller than 5%. The time-varying oscillation pattern of the concentrations of the CODCr and TN were rationally simulated, which showed that the model presented in this article could be used to assess the pollutant removal efficiency of the soil and plants in related cases.

关键词： pot test numerical modelling pollutant removal efficiency experiments

Parametric optimisation of two Pelton turbine runner designs using CFD

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Journal of Hydrodynamics 2015年第3期27卷 403-412页

作者： IDONIS Audrius PANAGIOTOPOULOS Alexandros AGGIDIS George A. ANAGNOSTOPOULOS John S. PAPANTONIS Dimitris E. Lancaster University Renewable Energy Group and Fluid Machinery Group Engineering Department Lancaster University School of Mechanical Engineering National Technical University of Athens

This paper aims to develop a generic optimisation method for Pelton turbine runners using computational fluid dynamics （CFD）. Two different initial runners are optimised to achieve more generic results. A simple bucket geometry based on existing bibliography is parameterised and initially optimised using fast Lagrangian solver （FLS）. It is then further optimised with a more accurate method using ANSYS Fluent. The second geometry is a current commercial geometry with good initial performance and is optimised using ANSYS CFX. The analytical results provided by CFX and Fluent simulations are used to analyse the characteristics of the flow for different runner geometries.

关键词： hydropower Pelton impulse turbines numerical modelling bucket geometry parameterisation optimisation

numerical simulation of sedimentation of microparticles usingthe discrete particle method

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Particuology 2008年第1期6卷 38-49页

作者： Chane-Yuan Yang Yulong Ding Dave York Walter Broeckx Institute of Particle Science and Engineering University of LeedsLeeds LS2 9JTUK Procter and Gamble Newcastle Technical Centre Newcastle-upon-Tyne NE12 9TSUK

A mathematical model has been formulated based on the combined continuous and discrete particle method for investigating the sedimentation behaviour of microparticles in aqueous suspensions, by treating the fluid phase as continuous and the particles phase as discrete, thus allowing the behaviour of individual particles to be followed and the evolution of the structure of the particle phase to be investigated as a function of time. The model takes into account most of the prevailing forces acting on individual particles including van der Waals attractive, electrostatic repulsive, gravitational, Brownian, depletion, steric, contact and drag forces. A code has also been developed based on the model. This paper reports some preliminary modelling results of mono-dispersed microparticles settling in aqueous suspensions under various conditions. The results show the short time dynamics of the fluid phase, which has a similar order of magnitude to the particle phase. Such short time dynamics could bear significance to processes such as particle aggregation when their size becomes very small. Preliminary analyses of the results have also been carried out on the evolution of particle settling based on a newly proposed parameter, local normalised volume fraction （LNVF）.

关键词： numerical modelling Combined continuous and discrete particle method Sedimentation Local normalised volume fraction lnterparticle interactions

Strategic sill pillar design for reduced hanging wall overbreak in longhole mining

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International Journal of Mining Science and Technology 2021年第5期31卷 975-982页

作者： Tuo Chen Hani S.Mitri Department of Mining and Materials Engineering Mc Gill UniversityMontrealQuebec H3A 0E8Canada

Steeply dipping,vein and tabular orebodies are traditionally extracted with longitudinal retreat mining methods such as Eureka and Avoca in a bottom-up sequence with delayed *** increase productivity,sill pillars in the orebody are used to separate mining zones thus allowing production to take place simultaneously in two or more *** such mining methods are productive,they may be accompanied with high volumes of hanging wall overbreak causing significant unplanned ore *** this work,it is shown through a mine design case study of a narrow vein deposit that a sill pillar could also play a significant role in limiting hanging wall *** demonstrate the role of sill pillar,a novel numerical modelling scheme is proposed to account for progressive stope wall overbreak.A numerical modelling approach of element death and rebirth is developed to allow for the detected stope overbreak to be immediately removed and replaced with backfill material before upper-level stope *** is further shown that the average overbreak volume could be reduced by as much as 33%when the sill pillar is strategically placed in the lower half of a mine plan.

关键词： Underground mine design Longitudinal mining Sill pillar design Unplanned ore dilution numerical modelling

modelling Study on the Plasma Flow and Heat Transfer in a Laminar Arc Plasma Torch Operating at Atmospheric and Reduced Pressure

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Plasma Science and Technology 2009年第2期11卷 163-170页

作者：王海兴陈熙潘文霞 School of Astronautics Beijing University of Aeronautics and Astronautics Department of Engineering Mechanics Tsinghua University Institute of Mechanics Chinese Academy of Sciences

A modelling study is performed to investigate the characteristics of both plasma flow and heat transfer of a laminar non-transferred arc argon plasma torch operated at atmospheric and reduced pressure. It is found that the calculated flow fields and temperature distributions are quite similar for both cases at a chamber pressure of 1.0 atm and 0.1 atm. A fully developed flow regime could be achieved in the arc constrictor-tube between the cathode and the anode of the plasma torch at 1.0 atm for all the flow rates covered in this study. However the flow field could not reach the fully developed regime at 0.1 atm with a higher flow rate. The arc-root is always attached to the torch anode surface near the upstream end of the anode, i.e. the abruptly expanded part of the torch channel, which is in consistence with experimental observation. The surrounding gas would be entrained from the torch exit into the torch interior due to a comparatively large inner diameter of the anode channel compared to that of the arc constrictor-tube.

关键词： non-transferred arc torch plasma flow and heat transfer numerical modelling