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Mechanism of the Impact of Floods and Typhoons on the Morphological Evolution of the Yangtze Estuary

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China Ocean Engineering 2023年第3期37卷 447-457页

作者： JIAO Jian DING Lei HAN Yu-fang SUN Jie-ying YANG Xiao-yu HUANG Yu-ming DOU Xi-ping Key Laboratory of port Waterway and Sedimentation Engineering of MOTNanjing Hydraulic Research InstituteNanjing 210029China State Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan 430072China

In the last two decades,the Yangtze Estuary has undergone significant changes under the influence of reduced sediment inflow and estuary *** study investigates the influence of floods and typhoons on sediment concentration and the morphological evolution of shoals and channels in the Yangtze *** analysis is conducted through the utilization of topographic data measured pre-and post-flood events and observations of hydro-sedimentary changes during *** using a generalized estuary mathematical model,this study examines the interplay between varying tidal ranges,tidal divisions,runoff volumes,and regulation projects on the erosion and deposition of shoals and channels in bifurcated *** results show that due to the implementation of river and waterway regulation projects,the impact of the 2020 flood on the main channel and shoal was significantly less than that of the1998 *** swing amplitude of the South Branch main channel ***,local river sections such as the Southern Waterway of Baimao Shoal exhibited *** typhoons,sediment concentration in the 20 cm above the bottom increased significantly and was closely related to wave processes,with a weakened correlation to tidal *** typhoons,high shoals in South Passage above 0 m were silted up,while the terrain on one side of the tail of Jiuduan Shoal in the downstream deep-water area was generally scoured due to strong wave *** generalized mathematical model of the bifurcated estuary revealed that M2 tidal component contributed most to the ero sion and deposition evolution of estuary shoals and channels,with floods exhibiting characteristics of sedime ntation on shoals and erosion on *** the implementation of a branch rectification project,branch resistance increased,diversion decreased,and the riverbed changed from pre-project erosion to post-project sedimentation,with an increase in erosion in non-project branches.

关键词： the Yangtze Estuary flood typhoon morphological evolution

research on Motion Performance of the Mobile Double-Causeway Pier System

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China Ocean Engineering 2008年第2期22卷 267-276页

作者：余建星田佳徐金利张翼飞杨晓蓉谭振东董文斌杜尊峰 Key Laboratory of port and Ocean Engineering Tianjin University Jinghai Bureau of Communications Military Transportation institute

Mobile offshore double-causeway pier system, a type of seashore unloading equipment, consists of two groups of multiple connected semi-submersible modules. This structure has wide application because most of the middle or mini type of vessels and ships can be moored to it. Based on the analysis of computational methods of multi-body motion response, a hydrodynamic model is set up and the three-dimensional potential theory in finite depth is adopted to calculate the three-dimensional motion response of this system. The double P-M spectrum is used to analyze the motion response in irregular waves. Different wave directions are specially taken into consideration, due to their various effects to the motion response. Furthermore, the calculated result is compared with that of the experiment, and it is proved that sway, heave, pitch and yaw motion are greatly constrained by mooring system. The comparison also indicates that the model can forecast the motion performance of the target, and that the calculated result can also be used as reference in connector and mooring system design.

关键词： offshore mobile pier system multi-floating body potential theory double P-M spectrum hydrodynamic analysis

Seabed deposition and erosion change and influence factors in the Yangshan Deepwater port over the years

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Acta Oceanologica Sinica 2019年第7期38卷 96-106页

作者： Shuhua Zuo Hualiang Xie Xiaoming Ying Cheng Cui Yuxin Huang Huaiyuan Li Mingxiao Xie National Engineering Laboratory for port Hydraulic Construction Technology Tianjin Research Institute for Water Transport EngineeringTianjin 300456China Key Laboratory of Engineering Sediment of Ministry of Transport Tianjin Research Institute for Water Transport EngineeringTianjin 300456China South China Sea institute of Marine Planning and Environmental research State Oceanic AdministrationGuangzhou 510300China

The seabed scouring and silting are very important to the construction of port and waterway engineering. Seabed deposition and erosion change is complicated due to the influence of sediment supply, human activities and other factors. The Yangshan Deepwater port is the new deep water harbor, which is an important part of the Shanghai International Shipping Service Center. Its construction has received much attention. At present, the water depth from the 1 st to the 3 rd harbor district is currently suitable under regular dredging and tidal current action. The fourth harbor district will be built in the world’s largest fully-automated deep water wharf. In the study, bathymetry change of the entire sea area of the Yangshan Deepwater port and the 4 th harbor district(i.e.,Phase IV project) waters were analyzed quantitatively using multiyear bathymetric, hydrological and sediment data. The results show that from 1998 to 2010, seabed changes are characterized by large volumes of erosion and sedimentation, which the southern part was deposited and the northern part was eroded in the inner harbor waters, but the seabed of the Kezhushan inlet was eroded. Seabed changes of Phase IV project waters generally show a scour tendency in recent few years with the annual scour rate about 0.7 m. Among the many factors, the existence of Kezhushan inlet and its influence of the western water flow play an important positive role in water depth changes under the ebb tide action.

关键词： Yangshan Deepwater port phase IV project water and sediment environment seabed deposition and erosion change diversion dike

A general method for modified function projective synchronization

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Journal of Harbin institute of Technology(New Series) 2010年第4期17卷 451-455页

作者：杜洪越曾庆双李锋袁得春 Space Control and Inertial Technology research Center Harbin Institute of Technology Beijing Capital International airport Company Limited Information Technology Department College of Electromechanical Engineering Northeast Forestry University

This paper investigates the modified function projective synchronization,which means that the drive system and the response system are synchronized up to a desired scale matrix of function. By the active control scheme,a general method for modified function projective synchronization is proposed. Numerical simulations on chaotic Rssler system and hyper-chaotic Chen system are presented to verify the effectiveness of the proposed scheme.

关键词： chaos synchronization active control modified function projective synchronization projective synchronization

Loading-unloading judgement for advanced plastic UH model

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Acta Mechanica Sinica 2020年第4期36卷 827-839页

作者： X.Feng Y.P.Yao R.N.Li Z.Wan X.Dai College of airport Civil Aviation University of ChinaTianjin 300300China School of Transportation Science and Engineering Beihang UniversityBeijing 100191China School of Automobile and Transportation Tianjin University of Technology and EducationTianjin 300222China research institute of Base and Foundation China Academy of Building ResearchBeijing 100013China

The unified hardening(UH)model proposed by Yao et al.(Geotechnique 2009)is the constitutive model which can consider the influence of the complex stress path and stress history on the deformation and strength of clays ***,the loading-unloading criterion of material model is defined as the change law of the intersection of current yield surface and the p axis,which makes the loading-unloading in the process of hardening and softening can be unified considered in UH ***,the Newton-Raphson method is adopted to attain the nonlinear problems solution in the finite element method of UH model,and the semi-implicit return mapping method is adopted to update *** application of the UH model in the finite element is *** then,the analyses of triaxial test are performed using the unit prediction and finite element *** results of the unit prediction method are compared with the experimental results to illustrate the rationality of the UH *** the results with the unit prediction method and the finite element method,the correctness of the finite element program of the UH model is ***,Ae three-dimensional firdte element andysis of embankment on soft soil is performed by the *** comparison between the results calculated by the UH model and the modified Cam-clay(MCC)model and the experimental data shows that the UH model is rational in analyzing the actual embankment engineering on soft soil.

关键词： Over-consolidated clay Unified hardening model Loading-unloading judgement Finite element method Stress-strain

Distributions of surficial sediments and its response to dynamic actions in the Xiamen Bay sea area, China

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Acta Oceanologica Sinica 2016年第4期35卷 9-18页

作者： ZUO Shuhua HAN Zhiyuan HUANG Yunxin HAN Jie XIE Mingxiao National Engineering Laboratory of port Hydraulic Construction Technology Tianjin Research Institute of Water Transport Engineering Key Laboratory of Engineering Sediment of Ministry of Transport Tianjin Research Institute of Water Transport Engineering State Key Laboratory of Estuarine and Coastal research East China Normal University School of Science Tianjin University of Technology

Sediment distribution is important for morphodynamic evolution and shoreline changes in coastal zones and estuaries. In the study, the data of 230 surface sediment samples collected from the Xiamen Bay sea area in September 2008 are used to investigate the spatial distribution and sediment transport pathway. The grain size distribution of surficial sediments in the Xiamen Bay area is shown distinctly in this study. In addition, the Grain Size Transport Analysis model is used for conveying trend analysis of the sediment in this area, particularly for determining the sediment movement trend. The results indicate that eight sediment types are present for samples, with clayey silt comprising the highest percentage in the study area at 65.22%. Moreover, in the different subareas, the characteristics of grain size parameters are obviously different owing to different sediment sources and hydrodynamic conditions. Furthermore, runoff, tides, and waves are the main forces dominating sediment dynamics on the seabed and tidal flats, and the sediment movement trend is closely related to hydrodynamic conditions.

关键词： Xiamen port Jiulongjiang Estuary Xiamen Bay surface sediments grain size dynamic response

The swirl and pyrolysis reaction synergistically enhance solid-solid heat transfer and product separation in cyclone pyrolyzer Author links open overlay panel

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Particuology 2024年第8期91卷 118-127页

作者： Haorui Niu Jingxuan Yang Wenhao Lian Nan Zhang Yongguo Li Hongzheng Ren Xiaogang Hao Guoqing Guan College of Chemical Engineering and Technology Taiyuan University of TechnologyTaiyuan030024 China School of Chemical Engineering and Technology North University of ChinaTaiyuan030051 China CNNC Key Laboratory on Radioactive Gas Purification Technology China Institute for Radiation ProtectionTaiyuan030006 China Energy Conversion Engineering Laboratory Institute of Regional InnovationHirosaki University3-BunkyochoHirosaki036-8561Japan

Cyclone pyrolyzer is a novel type of downer that combines centrifugal force field and double-layer cyclone *** on transfer behavior is helpful to optimize the pyrolyzer to meet the needs of *** this study,the Computational Particle Fluid Dynamics(CPFD)model is used to analyze the transfer behavior of binary particles,and finds that the swirl and reaction have a synergistic *** effect can increase the heating rate of the particles to the range of flash pyrolysis,and its mechanism lies in the flow field structure of the *** to the centrifugal force field,the particles gather to the near *** rapid swirl,which facilitates intense gas-solid heat transfer,leads to the rapid heating and pyrolysis of biomass *** the pyrolysis proceeds,the mass of the biomass particles becomes smaller and they are more easily affected by the gas flow in *** the action of gas flow,char particles serve as new heat carrier to form the inner cycle of particles,which strengthens the heating *** pyrolysis products are discharged from the exhaust port in time with the flow field of the pyrolyzer to achieve separation from the heat carrier and inhibit the occurrence of secondary reactions.

关键词： Biomass pyrolysis Cyclone pyrolyzer Intra-particle circulation Synergistic effect

The wave absorption efficiency of multi-layer vertical perforated thin plates

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Journal of Hydrodynamics 2018年第5期30卷 898-907页

作者： Bao-lei Geng Rong-quan Wang De-zhi Ning National Engineering Laboratory for port Hydraulic Construction Technology Tianjin Research Institute for Water Transportation EngineeringTianjin 300456China State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China

This paper analyzes the wave absorption efficiency of multi-layer perforated plates in an ideal fluid, based on the linear potential flow theory. The influence of the thickness, the porosity and the layout form of the plates on the wave absorptivity is studied on the assumption that all perforated plates are composed of the same materials and have the same thickness and porosity. The calculation results indicate that the larger the number of layers of the perforated plate set, the better the wave absorption efficiency, however, when the layer number exceeds a certain value, the efficiency of the plates is not significantly increased. For the case of porosity ？= 0.2, thickness b= 0.07 m and 4 layers of perforated plates with a distance l= 1.0 m between the layers, 90% of the energy of the wave within the incident wave period between 1.6 s and 4.4 s can be absorbed.

关键词： Wave absorptivity multi-layer vertical plate porous structure analytic method

A well-balanced positivity preserving two-dimensional shallow flow model with wetting and drying fronts over irregular topography

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Journal of Hydrodynamics 2018年第4期30卷 618-631页

作者：吴钢锋贺治国赵亮刘国华 School of Civil Engineering and Architecture Ningbo Institute of Technology Zhejiang University institute of port Coastal and Offshore Engineering Ocean College Zhejiang University institute of Hydraulic Structures and Water Environment Zhejiang University

This paper presents an improved well-balanced Godunov-type 2-D finite volume model with structured grids to simulate shallow flows with wetting and drying fronts over an irregular topography. The intercell flux is computed using a central upwind scheme, which is a Riemann-problem-solver-free method for hyperbolic conservation laws. The nonnegative reconstruction method for the water depth is implemented to resolve the stationary or wet/dry fronts. The bed slope source term is discretized using a central difference method to capture the static flow state over the irregular topography. Second-order accuracy in space is achieved by using the slope limited linear reconstruction method. With the proposed method, the model can avoid the partially wetting/drying cell problem and maintain the mass conservation. The proposed model is tested and verified against three theoretical benchmark tests and two experimental dam break flows. Further, the model is applied to predict the maximum water level and the flood arrival time at different gauge points for the Malpasset dam break event. The predictions agree well with the numerical results and the measurement data published in literature, which demonstrates that with the present model, a well-balanced state can be achieved and the water depth can be nonnegative when the Courant number is kept less than 0.25.

关键词： Shallow water equations central upwind scheme well-balanced wetting and drying positivity preserving second orderaccuracy