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FACTORS INFLUENCING THERMAL STRUCTURE IN A TRIBUTARY BAY OF THREE GORGES RESERVOIR

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Journal of Hydrodynamics 2011年第4期23卷 407-415页

作者： YU Zhen-zhen WANG Ling-ling college of water conservancy and hydropower Engineering Hohai University Nanjing 210098 China

To better understand the factors influencing the thermal structure of tributaries in the Three Gorges Reservoir （TGR）, a well validated three-dimensional hydrodynamic and water temperature model was proposed to simulate the water temperature distribution in the Xiangxi Bay, a representative tributary of TGR. The numerical results show that water temperature stratification seasonally occurred in the Xiangxi Bay, with stable vertical temperature profiles. It is found from the numerical experiments that three key factors are responsible for the formation of water temperature structure：（1） very often, the locations of thermocline are mainly determined by wind speeds, and the higher the wind speed is, the deeper the thermocline is located beneath the water surface, which could be expressed by a fitted exponential function, （2） the thermal structure is affected by static stability of water column, and the thermocline becomes closer to the water surface and its thickness increases with the increase of temperature, （3） due to the effect of the thermal density inflow, the water temperature of the hypolimnion tends to be uniform, however, even under the condition of larger inflow discharge, the influence of the inflow on the epilitnnion and the thermocline is not significant.

关键词： water temperature stratification numerical simulation density current influencing factors wind force static stability of water inflow discharge Three Gorges Reservoir (TGR)

THREE-DIMENSIONAL SIMULATION FOR EFFECTS OF BED DISCORDANCE ON FLOW DYNAMICS AT Y-SHAPED OPEN CHANNEL CONFLUENCES

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Journal of Hydrodynamics 2007年第5期19卷 587-593页

作者： WANG Xiao-gang YAN Zhong-min GUO Wei-dong college of water conservancy and hydropower Engineering Hohai University Nanjing 210098 China college of water conservancy Shenyang Agricultural University Shenyang 110161 China

Channel confluences are universally present in nature. They can be divided into two types： asymmetrical river confluences and symmetric river confluences. The latter is also called as the Y-shaped confluences. Most of previous work has paid more attention to the asymmetrical river confluences, but few studies have been conducted on the Y-shaped confluences. In this article, the effects of bed discordance on the flow patterns at ＂Y＂ shaped open-channel confluences were studied by using a 3-D numerical simulation. It is proved that the model can undertake quantitative assessment of the flow at confluences. The results indicate that there are a lot of differences between the Y-shaped confluence and asymmetrical confluence. The discordant bed height plays an important role at the Y-shaped junction.

关键词： Y-shaped junction discordant bed height,separation zone numerical simulation turbulent intensity,secondary flow lateral mixing

EMERGENCE ANGLE OF FLOW OVER AN AERATOR

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Journal of Hydrodynamics 2007年第5期19卷 601-606页

作者： WU Jian-hua RUAN Shi-ping college of water conservancy and hydropower Engineering Hohai University Nanjing 210098 China

Aerator is an important device for release works of hydraulic structures with high-speed flow in order to protect them from cavitation damage. This kind of protecting effect is related closely to cavity length below the aerator, while the cavity length is dominated by the emergence angle over the aerator. Therefore it is crucial to determine this angle accurately. In the present paper the affecting intensities of flow depth and the fluctuating velocity on this angle were analyzed through two introduced parameters. Furthermore, the improved expressions of emergence angle estimation, for both ramp-type and step-type aerators, were presented by means of 68 sets of experimental data from 6 projects based on error theory. The results showed that the present method has higher accuracy than the previously reported methods.

关键词： aerator cavitation damage cavity length,emergence angle flow depth fluctuating velocity

RESEARCH ON SEEPAGE MONITORING MODEL OF EARTH-ROCK DAM

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Journal of Hydrodynamics 2003年第1期15卷 78-83页

作者： Gu Chong shi, Zhang Qian fei college of water conservancy and hydropower Engineering, hohai university, nanjing 2.0098, china college of water conservancy and hydropower Engineering Hohai University Nanjing 210098 China

With the characteristics of seepage flow in earth-rock dams, a seepagemonitoring model was established based on the finite element method for 3-D seepage flow togetherwith observed data and was used to analyze and monitor the seepage of dams. In order to find out andmonitor the seepage status of the whole dam, the separation of seepage a-mount for dam body, damfoundation and side banks was made theoretically by using the model. Practical example shows thatthe accuracy of computed results is satisfactory and the separation results are more objective.

关键词： earth-rock dam seepage monitoring model

Numerical simulation of two-phase turbulent flow in hydraulic and hydropower engineering

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Science china(Technological Sciences) 2007年第Z1期50卷 79-89页

作者： DAI HuiChao1,2?, WANG LingLing1, GAO JiZhang3, ZHANG XiaoDong3 & YANG ZhongHua2 1 college of water conservancy and hydropower Engineering, hohai university, nanjing 2.0098, china 2 china Yangtze River Three Gorges Project Development Corporation, Yichang 443002, china 3 china Institute of water Resources and hydropower Research, Beijing 100044, china college of water conservancy and hydropower Engineering Hohai University Nanjing China china Yangtze River Three Gorges Project Development Corporation Yichang China china Institute of water Resources and hydropower Research Beijing China

In connection with the specific features of high velocity aerated flow generated by hydraulic engineering structures, the mathematical model is developed for high turbulence air-water two-phase flow with the use of twin flow theoretical model in this paper. Furthermore the numerical method is proposed to treat bubbled flows. In addition, on the basis of air-water stratified twin flow model, the new calculation methods and free surface tracking technique are proposed to describe complicated movements of the free surface. Finally, the proposed model is used to calculate artificial aerated flows. The computed results coincide quite well with experimental results. This means that the proposed method can provide solid basis for practical engineering design.

关键词： high turbulence two-phase flow twin flow model aerated flow free surface

Game model of safety monitoring for arch dam deformation

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Science china(Technological Sciences) 2008年第S2期51卷 76-81页

作者： SU HuaiZhi1,2,WU ZhongRu1,2,GU YanChang1,2,HU Jiang1 & WEN ZhiPing3 1 college of water conservancy and hydropower Engineering,hohai university,nanjing 2.0098,china 2 National Engineering Research Center of water Resources Efficient Utilization and Engineering Safety,nanjing 2.0098,china 3 Department of Computer Engineering,nanjing Institute of Technology,nanjing 210013,china college of water conservancy and hydropower Engineering Hohai University Nanjing China National Engineering Research Center of water Resources Efficient Utilization and Engineering Safety Nanjing China Department of Computer Engineering Nanjing Institute of Technology Nanjing China

Arch dam deformation is comprehensively affected by water pressure,temperature,dam's structural behavior and material properties as well as other *** them the water pressure and temperature are external factors(source factors) that cause dam deformation,and dam's structural behavior and material properties are the internal factors of deformation(resistance factors).The dam deformation is the result of the mutual game playing between source factors and resistance ***,resistance factors of structure and materials that reflect resistance character of arch dam structure are introduced into the traditional model,where structure factor is embodied by the flexibility coefficient of dam body and the maximum dam height,and material property is embodied by the elastic modulus of *** the basis of analyzing the correlation between dam deformation and resistance factors,the game model of safety monitoring for arch dam deformation is put forward.

关键词： arch dam deformation monitoring model flexibility coefficient game theory

THE UNITED METHOD FOR THE CALCULATION OF SEEPAGE CONTROL BY ADOPTING WEIGHTING SOIL LAYER ON THE BACK SIDE OF DIKE

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Journal of Hydrodynamics 2001年第4期13卷 92-97页

作者： Liu Chuan-shun, Yang Jin-zhong college of water conservancy and hydropower Engineering, Wuhan university, Wuhan 430072, china Wuhan Univ. Wuhan 430072 China

Constructing a weighting soil layer at the downstream toe of dike on layered ground is an effective measure to prevent the foundation from blowout failures. In this paper, a series of differential equations describing the seepage flow in layered dike foundation were established, and a united method combining analytic method with one-dimensional finite difference method was proposed for solving the equations. The case study shows that the results calculated by the united method are considerably identical to the computational results of Finite Element Method (FEM), and the united method is very simple and easy compared to the FEM.

关键词： dike weighting soil layer seepage calculation seepage control united method

MECHANISM AND PREDICTION OF MATERIAL ABRASION IN HIGH-VELOCITY SEDIMENT-LADEN FLOW

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Journal of Hydrodynamics 2006年第6期18卷 760-764页

作者： HUANG Xi-bin YUAN Yin-zhong college of water conservancy and hydropower Engineering Hohai University Nanjing 210098 China

The wall surface of material is prone to silt abrasion by high-velocity sediment-laden flow. The silt abrasion is different form cavitation erosion. In this article, the characteristics of silt abrasion were discussed, The mechanism of silt abrasion was analyzed and the formation and development of ripple shape on wall surface of material were explained thereafter. Based on turbulence theory and test data, some formulas were derived for predicting the abrasion rate of concrete wall surface in high-velocity sediment-laden flow. The calculated results show good agreement with the experimental data.

关键词： high-velocity sediment-flow silt abrasion,cavitation erosion abrasion rate

Numerical Simulation of water-Air Two-Phase Flow in Soil Slope under water Level Rise Condition

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Wuhan university Journal of Natural Sciences 2009年第5期14卷 442-446页

作者： ZHANG Xiaoyue,ZHU Yueming,FANG Chunhui,CHEN Shoukai college of water conservancy and hydropower Engineering,hohai university,nanjing 2.0098,Jiangsu,china college of water conservancy and hydropower Engineering Hohai University Nanjing China

In order to simulate the unsteady seepage in soil slopes under water level rise condition, including water seepage and air seepage, and to investigate the influence of the capillary pressure on the slope safety coefficient, the water-air two-phase flow model was used and its solving method and definition condition were given. By the two-phase flow model, the pore air and pore water seepage of a soil slope under steady seepage and water level rise conditions were shown, and the slope stability in different cases was analyzed from the simulation results. We find that under water level rise condition, the pore air pressure in the unsaturated zone increased evidently and the capillary pressure should be considered while the pore air pressure can be neglected in slope stability analysis.

关键词： water-air two-phase flow water level rise saturated-unsaturated seepage capillary pressure slope stability