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A HIGH RESOLUTION FINITE VOLUME METHOD FOR SOLVING SHALLOW WATER EQUATIONS

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Journal of Hydrodynamics 2000年第1期12卷 35-41页

作者： Wang Jia song School of civil engineering and Mechanics, shanghai Jiaotong university, shanghai 200030, P.R.chinaNi Hang gen department of civil and Structure engineering, Dalian university of Technology, Dalian 116024, P.R.china shanghai Jiaotong Univ Shanghai China

A high resolution finite volume numerical method for solving the shallow water equations is developed in this paper. In order to extend finite difference TVD scheme to finite volume method, a new geometry and topology of control bodies is defined by considering the corresponding relationships between nodes and elements. This solver is implemented on arbitrary quadrilateral meshes and their satellite elements, and based on a second order hybrid type of TVD scheme in space discretization and a two step Runge Kutta method in time discretization. Then it is used to deal with two typical dam break problems and very satisfactory results are obtained comparied with other numerical solutions. It can be considered as an efficient implement for the computation of shallow water problems, especially concerning those having discontinuities, subcritical and supercritical flows and complex geometries.

关键词： shallow water equations finite volume TVD scheme dam break bores

WATER TUNNEL EXPERIMENTAL INVESTIGATION ON THE DRAG REDUCTION CHARACTERISTICS OF THE TRAVELING WAVY WALL

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Journal of Hydrodynamics 2011年第1期23卷 65-70页

作者： YAO Yan LU Chuan-jing SI Ting ZHU Kun department of engineering Mechanics Shanghai Jiao Tong University Shanghai 200240 China Beijing Electromechanic engineering Institute Beijing 100074 China State Key Laboratory of Ocean engineering Shanghai Jiao Tong University Shanghai 200030 China department of modem Mechanics University of Science and Technology of China Hefei 230027 China

Drag reduction experiment of the traveling wavy wall at high Reynolds number is conducted.A suit of traveling wavy wall device is *** drag forces of the traveling wavy wall with various wave speeds（c）are measured under different water speeds（U）in the K15 cavitation water tunnel and are compared with that of the flat *** results show that the mean drag force of the traveling wavy wall have decreased and then increased with oscillation frequency increasing at the same flow *** different flow speeds,when traveling wave wall reached to the minimum of drag force,the corresponding the ratio of the wall motion phase speed c to flow speed U,c /U is slightly *** the parameters of the experiment,whenc /U reaches a certain value,the drag force of the traveling wavy wall can be less than that of the flat *** drag reduction can be up to 42%.Furthermore,as the value ofc /U increases,the traveling wavy wall can restrain the separation and improve the quality of flow field.

关键词： flow control drag reduction traveling wavy wall water tunnel test

Wind-resistant studies on tall buildings and structures

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Science china(Technological Sciences) 2010年第10期53卷 2630-2646页

作者： GU Ming State Key Laboratory of Disaster Reduction in civil engineering, Tongji university, shanghai 200092, china 1. State Key Laboratory of Disaster Reduction in civil engineering Tongji University Shanghai 200092 China

This paper introduces some aspects of wind-resistant studies of our research team on tall buildings and structures. Wind tunnel tests were carried out on 27 typical tall building models by using wind pressure scanning and HFFB techniques. The characteristics of wind pressures and forces acting on these buildings were analyzed. Some results have been adopted in a shanghai code for structural design of steel tall buildings. Interference effects on wind forces and wind pressures among two and three tall buildings were experimentally investigated with about 10000 testing conditions. Regression analyses of the interference factors under different parameter conditions were made and the main regression formulas are presented. Theoretical study on equivalent static wind loads of tall buildings and structures are then introduced. Especially,a new concept of "mode coupling factor" and a modified SRSS method for wind response and equivalent static wind load of complicated tall buildings and structures with consideration of multi mode contributions and their coupling effects are presented. Finally,practical applications of wind-resistant studies on tall building and structures,taking the Guangzhou New TV Tower as an example,are presented.

关键词： tall building and structure wind pressure and force interference effect equivalent static wind load application

Six-frame Algorithm Insensitive to the Linear Reference Phase and Detector Nonlinearity Errors for Phase-stepping Interferometry

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Chinese Journal of Lasers 1997年第2期B6卷 117-121页

作者： WEI Chunlong(department of Electronic engineering, shanghai university Jiading Campus,shanghai 201800, china)CHEN Mingyi DING Zheng(department of Mechanic engineering, shanghai university Jiading Campus),shanghai 201800, china)WANG Zhijiang(shanghai Inst shanghai Univ Shanghai China

A new six-frame algorithm based on Hariharan' s five-frame algorithmis derived. Although six-frame interferograms are needed, the new algorithm is immune to the effect of reference phase error or the second order detector nonlinearity ***, if they exist simultaneously, the new algorithm is insensitive to both of the errors. It is better than B. Zhao and Y. Surrel's six-frame algorithm to some extent.

关键词： interferometry phase-stepping algorithm

NUMERICAL INVESTIGATION ON THE AEROELASTIC BEHAVIOR OF AN AIRSHIP WITH HULL-FIN CONFIGURATION

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Journal of Hydrodynamics 2010年第2期22卷 207-213页

作者： LIU Jian-min LU Chuan-jing - XUE Lei-ping Marine engineering Institute Jimei University Xiamen 361021 China School of Naval Architecture Ocean and Civil Engineering Shanghai Jiao Tong University Shanghai 200240China State Key Laboratory of Ocean engineering Shanghai Jiao Tong University Shanghai 200030 China

Numerical investigation was conducted on an airship of hull-fin configuration for aerodynamic and aeroelastic characteristics in three-dimensional viscous *** mathematical model was built and the corresponding numerical code was developed for the fluid-structure interaction *** governing equations of the viscous flow with LL-Low Reynolds modified model were solved by the standard SIMPLE algorithm based on the finite volume method.A fluid-structure coupled method was employed to solve the nonlinear aeroelasticity problem for the *** computational results of the viscous flow are in good agreement with the experimental *** simulation on the aeroelastic behavior of the airship in a trimmed flight reveals the effect of structure flexibility on the aerodynamic performance.

关键词： fluid-structure interaction airship aeroelasticity flexibility

EXPERIMENTAL INVESTIGATION ON THE DRAG REDUCTION CHARACTERISTICS OF TRAVELING WAVY WALL AT HIGH REYNOLDS NUMBER IN WIND TUNNEL

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Journal of Hydrodynamics 2010年第5期22卷 719-724页

作者： YAO Yan LU Chuan-jing SI Ting ZHU Kun department of engineering Mechanics Shanghai Jiao Tong University Shanghai 200240 China Beijing Electromechanic engineering Institute Beijing 100074 China State Key Laboratory of Ocean engineering Shanghai Jiao Tong University Shanghai 200030 China department of Modern Mechanics University of Science and Technology of China Hefei 230027 China

Drag reduction experiments of the traveling wavy wall at high Reynolds number, ranging from 1.46×106 to 5.83×106 based on the free-stream velocity and the model length, were conducted. A suit of traveling wavy wall device was developed and its characteristics of drag reduction at high Reynolds number were investigated. The drag forces of the traveling wavy wall with various wave speeds （ c ） were measured at different wind speeds （U ） in the FL-8 low-speed wind tunnel and compared with the drag force of the flat plate. The results show that the mean drag force of the traveling wavy wall decreases as the value of c /U increases, at different wind velocities, the values of c /U corresponding to minimal drag force of the traveling wavy wall are different, when the values of c /U are larger than 0.6, the mean drag forces of the traveling wavy wall are smaller than those of the flat plate, and the drag reduction can be up to 60%. The drag reduction effectiveness of traveling wavy wall is thus achieved. Furthermore, as the value of c /U increases, the traveling wavy wall can restrain the separation and improve the quality of flow field.

关键词： flow control drag reduction traveling wavy wall wind tunnel test

Target tracking in wireless sensor networks using adaptive measurement quantization

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Science china(Information Sciences) 2012年第4期55卷 827-838页

作者： ZHOU Yan 1,2,LI JianXun 2 & WANG DongLi 1 1 Colleage of Information engineering,Xiangtan university,Xiangtan 411105,china 2.department of Automation,shanghai Jiao Tong university,shanghai 200240,china 1. Colleage of Information engineering Xiangtan University Xiangtan 411105 China2. Department of Automation Shanghai Jiao Tong University Shanghai 200240 China

Quantization/compression is usually adopted in wireless sensor networks (WSNs) since each sensor node typically has very limited power supply and communication *** consider the problem of target tracking in a WSN with quantized measurements in this *** is focused on the design of measurement quantizer with adaptive *** on the probability density function (PDF) of the signal amplitude measured at a random location and by maximizing the entropy,an adaptive design method for quantization thresholds is *** to the nonlinear measuring and quantization models,particle filtering (PF) is adopted in the fusion center (FC) to estimate the target *** Cram'er-Rao lower bounds (CRLBs) for tracking accuracy using quantized measurements are also ***,a simulation example on tracking single target with noisy circular trajectories is provided to illustrate the effectiveness of the proposed approach.

关键词： target tracking wireless sensor network adaptive quantization posterior Cram’er-Rao lower bound

A LINEAR HYBRID MODEL OF MSE AND BEM FOR FLOATING STRUCTURES IN COASTAL ZONES

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Journal of Hydrodynamics 2006年第6期18卷 649-658页

作者： ZHANG Jun MIAO Guo-ping School of Naval Architecture Ocean and Civil Engineering Shanghai Jiaotong University Shanghai 200030China The First Engineers Scientific Research Institute of the General Armaments Wuxi 214035 China

A linear hybrid model of Mild Slope Equation （MSE） and Boundary Element Method （BEM） is developed to study the wave propagation around floating structures in coastal zones. Both the wave refraction under the influence of topography and the wave diffraction by floating structures are considered. Hence, the model provides wave properties around the coastal floating structures of arbitrary shape but also the wave forces on and the hydrodynamic characteristics of the structures. Different approaches are compared to demonstrate the validity of the present hybrid model. Several numerical tests are carried out for the cases of pontoons under different circumstances. The results show that the influence of topography on the hydrodynamic characteristics of floating structures in coastal regions is important and must not be ignored in the most wave period range with practical interests.

关键词： hybrid model Mild Slope Equation (MSE),Boundary Element Method (BEM) marine floating structures,coastal regions wave propagation wave force

NUMERICAL SIMULATION OF TWO-DIMENSIONAL OVERTOPPING AGAINST SEAWALLS ARMORED WITH ARTIFICIAL UNITS IN REGULAR WAVES

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Journal of Hydrodynamics 2007年第3期19卷 322-329页

作者： LU Yong-jin LIU Hua WU Wei ZHANG Jiu-shan School of Naval Architecture Ocean and Civil Engineering Shanghai Jiaotong University Shanghai 200030 China shanghai Hydraulic engineering Design and Research Institute Shanghai 200063 China School of Naval Architecture Ocean and Civil Engineering Shanghai Jiaotong University Shanghai 200030China

A new mathematical model for the overtopping against seawalls armored with artificial units in regular waves was established. The 2-D numerical wave flume, based on the Reynolds Averaged Navier-Stokes （RANS） equations and the standard κ-ε turbulence model, was developed to simulate the turbulent flows with the free surface, in which the Volume Of Fluid （VOF） method was used to handle the large deformation of the free surface and the relaxation approach of combined wave generation and absorbing was implemented. In order to consider the effects of energy dissipation due to the armors on a slope seawall, a porous media model was proposed and implemented in the numerical wave flume. A series of physical model experiments were carried out in the same condition of the numerical simulation to determine the drag coefficient in the porous media model in terms of the overtopping discharge. Compared the computational value of overtopping over the seawall with the experimental data, the values of the effective drag coefficient was calibrated for the layers of blocks at different locations along the seawalls.

关键词： porous media overtopping seawall armored units 2-D numerical wave flume regular waves