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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 co.servancy 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 MODELING PURIFICATION PERFORMANCE OF POT TEST

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Journal of Hydrodynamics 2010年第5期22卷 709-718页

作者： DAI Yu WANG De-guan ZHANG Jin-feng LUAN Qing-hua Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes of Ministry of Education Hohai University Nanjing 210098 China college of Mechanics and Materials Science Hohai University Nanjing 210098 China college of Environmental Hohai University Nanjing 210098 China college of water co.servancy and hydropower Hebei University of Engineering Handan 056021 China

A three-dimensional mathematical model was developed to simulate the pollutant removal efficiency of the soil and plants in the pot test. The advection, dispersion, diffusion, adsorption, biochemical reaction and plant uptake processes were taken into account in the model. The three-dimensional modified Richards equation was used in simulating flow field. The mass balance law was employed in deriving the equation for pollutant transport, where the diffusion and dispersion were described with the Fick-type law, the adsorption was macroscopically expressed as form isotherm, and the bio-chemical degradation process was assumed to follow the Monod kinetics. The mathematical model was descretized by the finite element numerical method. In the pot test, the hydraulic loading was assumed to have the intermittent pattern simulating the rainfall duration and the occurrence of frequency, and the concentrations of pollutants in the influent and effluent were measured. The computed overall removal rates for the coDCr and TN in four cases are in the range of 90.62% - 95.43% and 85.01% - 96.46%, respectively. The differences between the computed and tested overall removal rates for the coDCr and TN are smaller than 5%. The time-varying oscillation pattern of the concentrations of the coDCr and TN were rationally simulated, which showed that the model presented in this article could be used to assess the pollutant removal efficiency of the soil and plants in related cases.

关键词： pot test numerical modelling pollutant removal efficiency experiments

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 co.servancy and hydropower engineering,hohai university,nanjing 210098,Jiangsu,china college of water co.servancy 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

EXPERIMENTAL STUDY AND NUMERICAL SIMULATION OF FLUORIDE IN SAND

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Journal of Hydrodynamics 2006年第6期18卷 748-751页

作者： ZHANG Hong-mei SU Bao-yu School of Resources and Safety engineering China University of Mining and Technology Beijing 100083China college Of water co.servancy and hydropower engineering Hohai University Nanjing 210098China

The transport and transformation of fluoride in sand were studied by using soil tank test under the condition of saturated water in this article. Based on the analysis of the laboratory experiments, the rules of fluorine transportation and transformation were simulated in sand by solving the advection-diffusion equation. Through comparison between computed results and observed data , it is shown that the established model and determined parameters could be used to simulate the fluoride transport in sand.

关键词： sand fluoride dynamic test numerical simulation

Risk analysis model for landslide mass of high slope in dam area

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Science china(Technological Sciences) 2008年第S2期51卷 25-31页

作者： GU ChongShi1,2,HE XianFeng3,4,WU ZhongRu1,2 & SU HuaiZhi1,2 1 college of water co.servancy and hydropower engineering,hohai university,nanjing 210098,china 2 National engineering Research Center of water Resources Efficient Utilization and engineering Safety,nanjing 210098,china 3 Yellow River Institute of Hydraulic Research,Zhengzhou 450003,china 4 Embankment Security Defect Prevention and control engineering Research Center of MWR,Zhengzhou 450003,china college of water co.servancy and hydropower engineering Hohai University Nanjing China National engineering Research Center of water Resources Efficient Utilization and engineering Safety Nanjing China Yellow River Institute of Hydraulic Research Zhengzhou China Embankment Security Defect Prevention and control engineering Research Center of MWR Zhengzhou China

In order to identify the threat of reservoir bank landslide to dam safety and reduce the risk of dam failure,impact factors of the landslide are *** concept of landslide risk degree is put forward to measure the threat of landslide to dam *** monotony of the landslide risk assessment function which changes with different affecting factors is analyzed *** on gene automatic programming,a data mining model of the landslide risk assessment function is constructed combined with impact factors of reservoir bank landslide on dam *** the assessment function of landslide risk has been excavated and established according to practical project information,which provides a valuable reference for analyzing the impact of landslide on dam risk.

关键词： landslide dam failure risk landslide risk

NEW METHOD OF SIMULATING coNCENTRATED DRAIN HOLES IN SEEPAGE coNTROL ANALYSIS

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Journal of Hydrodynamics 1999年第3期11卷 27-35页

作者： Zhan Mei li, Su Bao yu , Liu Jun yong, Shen Zhen zhong college of water co.servancy and hydropower engineering, hohai university, nanjing 210098, P.R.china (Received Aug.1, 1998)

In this paper, based upon the basic solution of sink, the approximate solution of single drain hole in finite elements is derived by use of the superposition principle. Then, the theoretical solution is extended to the case of some drain holes in one finite element, and the method is used in seepage control analysis with quick convergence and high accuracy. On the other hand, if the positions of the drain holes are changed, only some control factors of drain holes are changed, but the finite element grid need not to be reformed. Therefore, the method is more suitable in optimal research of seepage control.

关键词： concentrated drain hole approximate solution seepage control optimal research

Establishing time-dependent model of deformation modulus caused by bedrock excavation rebound by inverse analysis method

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Science china(Technological Sciences) 2008年第S2期51卷 1-7页

作者： WU ZhongRu1,2,GU YanChang1,3,GU ChongShi1,2,GUO HaiQing1 & SU HuaiZhi1,2 1 hohai university,nanjing 210098,china 2 National engineering Research Center of water Resources Efficient Utilization and engineering Safety,nanjing 210098,china 3 nanjing Hydraulic Research Institute,nanjing 210029,china hohai university Nanjing China National engineering Research Center of water Resources Efficient Utilization and engineering Safety Nanjing China nanjing Hydraulic Research Institute Nanjing China

Rock rebound relaxation deformation,or even rock burst,caused by the excavation of dam base and abutment or high rock slope affects their stability and results in the fall of mechanical properties of the *** an inverse analysis method was proposed in this paper to establish the time-dependent model of deformation modulus caused by excavation *** basic principle is based on the combination of observed data of the excavation rebound deformation of dam abutment or rock slope,and the calculated rebound deformation by FEM under ground stress at the corresponding time in the excavation *** norm of the residuals of observed data and calculated data are taken as the objective ***,the time-dependent model of bedrock deformation modulus can be *** method displays its significance in the design of excavation,construction and operation management of dam base and high slope.

关键词： dam base rebound deformation modulus inverse analysis method time-dependent model Xiaowan hydropower Station

HYDRODYNAMIC CHARACTERISTICS OF CHINESE STURGEON SPAWNING GROUND IN YANGTZE RIVER

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Journal of Hydrodynamics 2008年第2期20卷 225-230页

作者： YANG Yu YAN Zhong--min CHANG Jian-bo nanjing Hydraulic Research Institute Nanjing 210029 China State Key Laboratory of Hydrology-water Resources and Hydraulic engineering Nanjing 210029 China college of water co.servancy and hydropower engineering Hohai University Nanjing 210098 China Institute of Hydro-ecology Wuhan 430072 China

Since the construction of the Gezhouba Dam on the Yangtze River in 1981, it has been found that the Chinese Sturgeon, Acipensor sinensis, performs natural propagation annually in a narrow reach downstream close to the Gezhouba Dam site. This might allow one to better investigate the river hydrodynamic conditions of the Chinese Sturgeon spawning ground. In this article, spatial Kinetic Energy Gradient （KEG） and absolute value of vorticity were computed along the river sections from measured data. The relation between Spawn Density per Unit Area （SDUA） and vorticity strength and between SDUA and KEG were worked out. The Results showed that the vorticity and KEG were both effective parameters for describing the hydrodynamic characteristics of Chinese Sturgeon spawning ground. The Chinese Sturgeons prefer to spawn in the river sections where the value of vorticity strength is larger than 0.4 s^-1 and KEG is larger than 0.029 Jkg^-1m^-1.

关键词： hydrodynamic characteristics Chinese Sturgeon spawning ground vorticity kinetic energy gradient Spawn Densityper Unit Area (SDUA)

INFLUENCE OF FILLING water ON AIR coNCENTRATION

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Journal of Hydrodynamics 2011年第5期23卷 601-606页

作者： WU Jian-hua MA Fei DAI Hui-chao college of water co.servancy and hydropower engineering Hohai University Nanjing 210098 China

The filling water inside the cavity below an aerator occurs for the flow of low Froude number or the small bottom slope of a spillway. The aerator may cease to protect against cavitation damages, and may even act as a generator of cavitation if it is fully filled by water. The experiments were conducted to investigate the influences of the geometric parameters, and then the filling water on the air concentration. The results show that the filling water, or the net cavity length, is closely related to the plunging jet length for a given aerator, and the air concentration at some section is proportional to the ratio Ln/Lj at a fixed Lj for different geometric parameters of aerators. Secondly, at the same ratio of Ln / Lj, the aerator with a larger height or a larger angle of ramp, or a larger bottom slope, would have a larger plunging jet length, and then a larger net cavity length based on the ratio of Ln / Lj. As a result, the large space of cavity, or the high air concentration of the flow could be obtained although the filling water increases also based on the fact that Lf = Lj - Ln. It is the space of the cavity that is the dominant factor to affect the air concentration of the flow.

关键词： aerator air concentration filling water jet length net cavity length