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Advances in Applied Mathematics and Mechanics 2013年第4期5卷 442-460页

作者： B.Bialecki g.fairweather J.C.Lopez-Marcos Department of AppliedMathematics and Statistics Colorado School of MinesGoldenCO 80401USA Mathematical Reviews American Mathematical Society416 Fourth StreetAnn ArborMI 48103USA Departamento de Matem´atica Aplicada Universidad de ValladolidValladolidSpain

We formulate and analyze the Crank-Nicolson Hermite cubic orthogonal spline collocation method for the solution of the heat equation in one space variable with nonlocal boundary conditions involving integrals of the unknown solution over the spatial *** an extension of the analysis of Douglas and Dupont[23]for Dirichlet boundary conditions,we derive optimal order error estimates in the discrete maximum norm in time and the continuous maximum norm in *** discuss the solution of the linear system arising at each time level via the capacitance matrix technique and the package COLROWfor solving almost block diagonal linear *** present numerical examples that confirm the theoretical global error estimates and exhibit superconvergence phenomena.

关键词： Heat equation nonlocal boundary conditions orthogonal spline collocation Hermite cubic splines convergence analysis superconvergence

Lattice approaches to packed column simulations

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Particuology 2008年第6期6卷 404-411页

作者： Richard Caulkin Mike fairweather Richard A. Williams Institute of Particle Science and Engineering School of ProcessEnvironmental and Materials EngineeringUniversity of Leeds

This work presents a review of the findings into the ability of a digitally based particle packing algorithm, called DigiPac, to predict bed structure in a variety of packed columns, for a range of generic pellet shapes frequently used in the chemical and process engineering industries. Resulting macroscopic properties are compared with experimental data derived from both invasive and non-destructive measurement techniques. Additionally, fluid velocity distributions, through samples of the resulting bed structures, are analysed using lattice Boltzmann method （LBM） simulations and are compared against experimental data from the literature.

关键词： Packing algorithm Bed structure Packed columns Macroscopic properties Lattice Boltzmann simulations

Particle behavior in a turbulent pipe flow with a flat bed

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Particuology 2023年第10期81卷 58-72页

作者： Min Liu Yanlin Zhao Yudong Yan Michael fairweather Jun Yao International Joint Laboratory on Clean Energy Science and Technology Beijing Key Laboratory of Process Fluid Filtration and SeparationCollege of Mechanical and Transportation EngineeringChina University of Petroleum-BeijingBeijing102249China School of Chemical and Process Engineering University of LeedsLeedsLS29JTUK

Particle behavior in a turbulent flow in a circular pipe with a bed height h=0.5R is studied at Reb=40,000 and for two sizes of particles(5μm and 50μm)using large eddy simulation,one-way coupled with a Lagrangian particle tracking *** secondary flows are found within the pipe,with the curved upper wall affecting the secondary flow formation giving rise to a pair of large upper vortices above two smaller vortices close to the pipe *** behavior of the two sizes of particle is found to be quite *** 50μm particles deposit forming irregular elongated particle streaks close to the pipe floor,particularly at the center of the flow and the pipe corners due to the impact of the secondary *** deposition and resuspension rate of the 5μm particles is high near the center of the floor and at the pipe corners,while values for the 50μm particles are greatest near the *** the curved upper wall of the pipe,the deposition rate of the 5μm particles increases in moving from the wall center to the corners,and is greater than that for the larger particles due to the effects of the secondary *** maximum resuspension rate of the smaller particles occurs above the pipe corners,with the 50μm particles showing their highest resuspension rate above and at the corners of the pipe.

关键词： Sedimentary duct Secondaryflow Particle behavior Large eddy simulation

Investigation of Detailed Kinetic Scheme Performance on Modelling of Turbulent Non-Premixed Sooting Flames

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Journal of Thermal Science 2011年第6期20卷 548-555页

作者： Y.Yunardi D.Darmadi H.Hisbullah M.fairweather Department of Chemical Engineering Syiah Kuala University Energy and Resources Research Institute SPEMEUniversity of LeedsLeedsUnited Kingdom

This paper presents the results of an application of a first-order conditional moment closure （CMC） approach coupled with a semi-empirical soot model to investigate the effect of various detailed combustion chemistry schemes on soot formation and destruction in turbulent non-premixed flames. A two-equation soot model repre- senting soot particle nucleation, growth, coagulation and oxidation, was incorporated into the CMC model. The turbulent flow-field of both flames is described using the Favre-averaged fluid-flow equations, applying a stan- dard k-c turbulence model. A number of five reaction kinetic mechanisms having 50 - 100 species and 200 - 1000 elementary reactions called ABF, Miller-Bowman, gRI-Mech3.0, Warnatz, and Qin were employed to study the effect of combustion chemistry schemes on soot predictions. The results showed that of various kinetic schemes being studied, each yields similar accuracy in temperature prediction when compared with experimental data. With respect to soot prediction, the kinetic scheme containing benzene elementary reactions tends to result in a better prediction on soot concentrations in comparison to those contain no benzene elementary reactions. Among five kinetic mechanisms being studied, the Qin combustion scheme mechanism turned to yield the best prediction on both flame temperature and soot levels.

关键词： soot conditional moment closure combustion kinetic scheme non-premixed turbulent flame

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粒状腐蚀产物在管道中的沉积机理

金属学报 2011年第7期47卷 804-808页

作者：姚军 Michael fairweather 李宁厦门大学能源研究院厦门361005 School of Process Environmental and Materials EngineeringUniversity of Leeds

利用大涡模拟方法和Lagrangian方法研究了腐蚀产物（颗粒）在核反应堆冷却回路管道中的沉积现象（Reynolds数2．5×10^5）．利用Lagrangian方法跟踪颗粒轨迹，颗粒运动方程中包含牵引力、升力、浮力和重力．流体和颗粒是单相耦合，计算... 详细信息

利用大涡模拟方法和Lagrangian方法研究了腐蚀产物（颗粒）在核反应堆冷却回路管道中的沉积现象（Reynolds数2．5×10^5）．利用Lagrangian方法跟踪颗粒轨迹，颗粒运动方程中包含牵引力、升力、浮力和重力．流体和颗粒是单相耦合，计算中忽略颗粒-颗粒间碰撞．流场计算结果与实验数据以及直接数值模拟计算结果吻合良好．计算结果显示，小颗粒趋于沉积在管道中心处，而大颗粒趋于沉积在管道边缘，这种趋势随颗粒粒径增大而加强．在近管道底部区域，颗粒沉积分布密度随颗粒粒径的增大而提高，小颗粒在底部分布均匀，而大颗粒在流向速度低速区聚集．

关键词：腐蚀产物颗粒大涡模拟沉积

Analysis of Turbulence and Surface growth Models on the Estimation of Soot Level in Ethylene Non-Premixed Flames

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Journal of Thermal Science 2018年第1期27卷 78-88页

作者： Y.Yunardi Edi Munawar Wahyu Rinaldi Asbar Razali Elwina Iskandar M.fairweather Department of Chemical Engineering Syiah Kuala University Department of Mechanical Engineering Syiah Kuala University Department of Chemical Engineering State Polytechnics of Lhokseumawe School of Chemical and Process Engineering University of Leeds

Soot prediction in a combustion system has become a subject of attention, as many factors influence its accuracy. An accurate temperature prediction will likely yield better soot predictions, since the inception, growth and de- struction of the soot are affected by the temperature. This paper reported the study on the influences of turbulence closure and surface growth models on the prediction of soot levels in turbulent flames. The results demonstrated that a substantial distinction was observed in terms of temperature predictions derived using the k-c and the Rey- nolds stress models, for the two ethylene flames studied here amongst the four types of surface growth rate model investigated, the assumption of the soot surface growth rate proportional to the particle number density, but inde- pendent on the surface area of soot particles,f（As） = pNs, yields in closest agreement with the radial data. Without any adjustment to the constants in the surface growth term, other approaches where the surface growth directly proportional to the surface area and square root of surface area, f （As） = As and f （A,） = √As, result in an un- der-prediction of soot volume fraction. These results suggest that predictions of soot volume fraction are sensitive to the modelling of surface growth.

关键词： soot conditional moment closure combustion surface growth non-premixed turbulent flame