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A LARGE EDDY SIMULATION TURBULENCE MODEL FOR COASTAL SEAS AND SHALLOW WATER PROBLEMS

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Journal of Hydrodynamics 2001年第4期13卷 24-27页

作者： Zhan, Jie-Min Li, Yok-Sheung dept. of Appl. Mech. and eng. Zhongshan Univ. Guangzhou 510275 China

In large scale motions of circulations in coastal seas and shallow-water problems, different characteristics of flow in the horizontal plane and in the vertical direction are expected. A new large eddy simulation model was proposed. There are some differences between the present method and the other LES models. The philosophy of the large eddy simulation and the directional eddy viscosity method were applied in the horizontal plane and in the vertical direction, respectively. Compared with the other LES models in which there is no difference between horizontal viscosity and vertical viscosity, the proposed method is reasonable.

关键词： Computational fluid dynamics Computer simulation

Experimental and Numerical Analysis of Natural Bio and Syngas Swirl Flames in a Model Gas Turbine Combustor

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Journal of Thermal Science 2016年第5期25卷 460-469页

作者： S.Iqbal A.C.Benim S.Fischer F.Joos D.KluB A.Wiedermann CFS Dept.Mechanical and Process Eng.Düsseldorf University of Applied Sciences Laboratory of Turbomachinery Helmut Schmidt University Viessmann Werke Berlin GmbH eng.neering Gas Turbines MAN Diesel and Turbo SE

Turbulent reacting flows in a generic swirl gas turbine combustor model are investigated both numerically and *** the investigation,an emphasis is placed upon the external flue gas recirculation,which is a promising technology for increasing the efficiency of the carbon capture and storage process,which,however,can change the combustion behaviour significantly.A further emphasis is placed upon the investigation of alternative fuels such as biogas and syngas in comparison to the conventional natural *** are also investigated numerically using the open source CFD software *** the numerical simulations,a laminar flamelet model based on mixture fraction and reaction progress variable is *** turbulence model,the SST model is used within a URANS *** results are compared with the experimental data,where a fair agreement is observed.

关键词： Gas turbine combustion turbulent combustion URANS laminar flamelet method

A STUDY OF THE POSTBUCKLING PATH OF CYLINDRICALLY CURVED PANELS OF LAMINATED COMPOSITE MATERIALS DURING LOADING AND UNLOADING

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applied Mathematics and mechanics(eng.ish Edition) 1990年第7期11卷 651-657页

作者：董万林黄小清 dept. of eng. Mech. South China Univ. of Tech. Guangzhou

In this paper, Dynamic Relaxation Method is applied to study the postbuckling path of cylindrically curved panels of laminated composite materials during loading and unloading. The phenomenon that loading paths do not coincide with unloading paths has been found. Numerical results are given for cylindrically curved cross-ply panels subjected to uniform uniaxial compression under two types of boundary conditions. The influence of the number of layers, the panels curvature and the initial imperfection on the postbuckling paths is discussed.

关键词： A STUDY OF THE POSTBUCKLING PATH OF CYLINDRICALLY CURVED PANELS OF LAMINATED COMPOSITE MATERIALS DURING LOADING AND UNLOADING

Three-dimensional configurations of organic/inorganic hybrid nanostructural blocks (I).A quantum mechanical investigation for ladder-like structure of vinylsilsesquioxane

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Science China Chemistry 2004年第5期47卷 388-395页

作者： ZHANG Xingwen1,2, HU Lijiang1, HUANG Yudong1, SUN Dezhi2 & SUN Yi3 1. Department of applied Chemistry,Harbin Institute of Technology, HUANG Yudong, Harbin 150001, China 2. Department of Environmental eng.neering, Harbin Institute of Technology, Harbin 150001, China 3. Department of Experimental mechanics,Harbin Institute of Technology, Harbin 150001, China dept. of applied Chem. Harbin Inst. of Technol. Harbin 150001 China dept. of Environ. eng. Harbin Inst. of Technol. Harbin 150001 China dept. of Experimental Mech. Harbin Inst. of Technol. Harbin 150001 China

The organic/inorganic hybrid nanostructural vinylsilsesquioxanes (VSSO) were prepared from the hydrolytic condensation of vinyltrimethoxysilane (VMS). The proposed formu- las of VSSO were assigned with standard spectroscopic techniques, FTIR, NMR (1H, C and 13 29Si) and MALDI-TOF MS, and a generic formula of the SSO, Tn(OH)x(OR’)y(x, y = 0, 1, 2…; n = 1, 2…; T = RSiO1.5 ?(x+y)/2n). Geometric parameters (Si-O and Si-C bond leng.hs, Si-O-Si and O-Si-O bond angles) and total energies of the multi-structures of VSSO were calculated by a quantum mechanical investigation and molecular symmetries. According to the results of the calculation, most molecules had stabler ladder structures than the cage isomers, therefore, the most probably reasonable and optimum structure of the VSSO system was the ladder type.

关键词： vinyltrimethoxysilane (VMS), silsesquioxanes (SSO), sol-gel process, quantum mechanical calculation, MNDO.

FORCED WAVE PROPAGATION IN VISCOELASTIC CABLE WITH SMALL SAG

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Acta Mechanica Solida Sinica 2001年第2期14卷 147-154页

作者： Li Yinghui Jian Kailin~1 Gao Qing Yin Xuegang~1 (Department of applied mechanics and eng.neering, Southwest Jiaotong University, Cheng.u 610031, China) (1 State Key Laboratory of mechanical Transmission, Chongqing University, Chongqing 400044, China) dept. of Appl. mechanics and eng. Southwest Jiaotong University Chengdu 610031 China Stt. Key Lab. of Mech. Transmission Chongqing University Chongqing 400044 China

Based on the linear viscoelastic differential constitutive law andcable structural model, the coupled longitudinal-transverse wavesthat propagate along a viscoelastic cable with small curvature isinvesti- gated. A mathematical model is presented that describes thethree-dimensional nonlinear response of a vis- coelastic cable. Anasymptotic form of this model is obtained for the linear response ofcables having small equilibrium curvature.

关键词： viscoelastic cable small equilibrium curvature cut-off frequency

Modeling of large scale solar cell handling robot with belt-driven flexible arms

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Theoretical & applied mechanics Letters 2013年第1期3卷 77-80页

作者： Eun Yim Cho Jinsu Kim Sungsoo Rhim dept. of Mech. eng. Kyung Hee University

To increase the competition of the solar energy collection system, the size of the solar panel module during the manufacturing process is being increased continuously. As the size of the solar panel increases, the size of the robot to handle the panel increased also. The change in scale of the robot inevitably results ill the amplification of the adverse effect of tile flexure. The main source of the flexure in the large scale solar cell panel handling system is the long and thin fork fingers of the [land and the solar cell panel. In addition, tile belt-driven actuator system used by most of the large scale panel handling robot is another significant source of the vibration. In this paper, the flexible multi body dynamic model of a large scale solar cell panel handling robot, which is being designed and constructed with the help of Kyung Hee University, is developed. The belt-driven system in the robot is also modeled as flexible system and included ill the robot to represent the actual vibration characteristics of the actuator system. C 2013 The Chinese Society of Theoretical and applied mechanics. [doi： 10.1063/2.1301310]

关键词： flexible belt drive flexible multi body dynalnics modeling panel handling robot

PROPULSIVE PERFORMANCE AND VORTEX SHEDDING OF A FOIL IN FLAPPING MOTION

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Journal of Hydrodynamics 2003年第5期15卷 7-12页

作者： Yang Yan, Lu Xi yun, Yin Xie zhen Department of mechanics and mechanical eng.neering, University of Science and Technology of China, Hefei 230026, China, dept. of Mech. and Mech. eng. Univ. of Sci. and Technol. of China Hefei 230026 China

The propulsive performance and vortex shedding of oscillating foil, whichmimics biological locomotion, were numerically investigated. The objectives of this study were todeal with unsteady force, in particular thrust force, exerted on the foil in pitching and plungingmotions, and to explore the relation of the propulsive performance with vortex structures near thefoil and vortex shedding in the near wake. The two-dimensional incompressible Navier-Stokesequations in the vorticity and stream-function formulation were solved by fourth-order essentiallycompact finite difference schemes for the space derivatives and a fourth-order Runge-Kutta schemefor the time advancement. To reveal the mechanism of the propulsive performance, the unsteady forceand the shedding of the trailing- and leading-edge vortices of the foil were analyzed. The effectsof some typical factors, such as the frequency and amplitude of the oscillation, the phasedifference between the pitching and plunging motions, and the thickness ratio of the foil, on thevortex shedding and unsteady force were discussed.

关键词： vortex dynamics vortex shedding thrust force unsteady flow flappingmotion

AN INVESTIGATION OF TURBULENT HEAT TRANSFER IN CHANNEL FLOWS BY LARGE EDDY SIMULATION

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Journal of Hydrodynamics 2002年第2期14卷 29-35页

作者： Dong Yu-hong, Zhong Feng.quan, Lu Xi-yun, Zhuang Li-xian Department of mechanics and mechanical eng.neering, University of Science and Technology of China, Hefei 230026, China dept. of Mech. and Mech. and eng. Univ. of Sci. and Technol. of China Hefei 230026 China

Large Eddy Simulation (LES) of fully developed turbulent channel flow with heat transfer was performed to investigate the effects of the Reynolds number on the turbulence behavior. In the present study, the bottom wall of the channel was cooled and the top wall was heated. The Reynolds numbers, based on the central mean-velocity and the half-width of the channel, were chosen as 4000, 6000, 10 4 and 2×10 4, and the Prandtl number as 1.0. To validate our calculations, the present results were compared with available data obtained by Direct Numerical Simulation (DNS), which proves to be in good agreement with each other. To reveal the effects of the Reynolds number, some typical quantities, including the velocity fluctuations, temperature fluctuation, heat fluxes and turbulent Prandtl number, were studied.

关键词： Large Eddy Simulation (LES) turbulent channel flow Subgrid Scale (SGS) model heat transfer stratified turbulence

Molecular dynamics simulations on the relationship between the elastic parameters and the molecular structures of nano-hybrid POSS materials

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Journal of Harbin Institute of Technology(New Series) 2006年第2期13卷 164-172页

作者：曾凡林孙毅胡立江 dept. of Astronautic Science and mechanics Harbin Institute of Technology Harbin 150001 China dept. of applied Chemistry Harbin Institute of Technology Harbin 150001 China

To research the relationship between the elastic parameters and the molecular structures of nano hybrid polyhedral oligomeric silsesquioxanes （POSS） materials, the mechanical properties at different temperatures for three POSS polymers with different molecular architectures, polymerlized norbornene POSS homopolymer （PNPOSS, pedant architecture）, γ- （2, 3 glycidoxy） propyl diaminoethane POSS polymer （GPDP, catena architecture） and trimethoxysilylcyelopentyl POSS polymer （ TSCP, cage - cage network architecture） were obtained by molecular dynamics simulations based on the Compass force-field. Results indicate that the moleculax architectures of the POSS polymers have great influence on the reinforced effects. The effect of the cage-cage network architecture is best, while that of the catena architecture takes second place and the pedant architecture has the least influence comparatively. The reinforced effects of the POSS monomers were examined. The influences of the temperatures on these effects were analyzed also. It may provide some basis for the reasonable applications of the excellent mechanical properties of the organic-inorganic nano-hybrid materials. It may also provide references for exploitation and design of the POSS materials.

关键词： nano-hybrid materials POSS molecular dynamics simulations