Journal of Hydraulic Engineering
No.01 1999
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Journal of Hydraulic Engineering No.01 1999 |
Water and grain of China in 21century
Chen Minjian, Liang Ruiju, Liu Yulong
(China Institute of Water Resources and Hydropower Research)
Abstract Based upon the analysis on the availability of water resources and its regional distribution together with its influence on grain production according to the statistics of the past decades,this paper expounds the probable quantity limit of water resources and the quantitative indexes of grain production in the next century of China.The analysis has been undertaken for the river basin-level individually.The conclusion that the probable maximum grain production in the next century will be about 0,889 billion tons per year has been drawn.The strategic options on grain production are given accordingly.
Key words Combination of water and land nesources, water resources utility limit, potentiality of grain production,strategic options.
Study on failure cause of bottom slabs in stilling basin
for Wu Qiangxi Hydropower Station
| Liu Peiqing | Gao Jizhang, Li Guifen |
| (Beijing University of Aeronautics and Astronautics) | (Institute of Water Resources and Hydropower Research) |
Abstract By using the integral equation of momentum,the mechanism of energy dissipation in the stilling basin with flaring piers is analyzed.According to the operating conditions of Wu Qiangxi Project,the failure cause of bottom slabs in the stilling basin is investigated.
Key words flaring piers,stilling basin,failure,bottom slabs.
Hydraulic model study on shaft-orifice spillway
Ni Hangen, Yang Jingfang, Wang Qingguo
(Dalian University of Technology)
Abstract The hydraulic characteristics and flow induced vibration of a shaft-orifice spillway are studied in a model test.The result shows that the spillway operates effectively and no unfavorable hydraulic phenomenon has been found.The vibration is negligible.
Key words Shaft-spillway,hydraulic model test,hydraulic characteristics,vibration.
The numerical simulation on impact of thermal discharge on
eutrophication in lakes and reservoirs
| Chen Kaiqi, Li Pingheng | Mi Xiaobin |
| (China Institute of Water Resources and Hydropower Research) | (Tsinghua University) |
Abstract A numerical model for predicting the impact of water discharge from thermal power stations or nuclear power plants on eutrophication in lakes and reservoirs is presented in this paper.The algorithm of the modified hybrid method of fractional steps is used to solve 2D conservation type shallow water circulation equations and energy equations.Based on the accurate numerical simulation of flow and temperature fields,using the single step-one level ecological dynamic model,the influence of algae growth process resulted from water temperature rising is considered with the model of single factor analysis.T his model is tested and put into application in the practical design of a large power plant project.
Key words eutrophication, numerical simulation, thermal discharge, lakes and reservoirs.
The dynamic simulation of hydraulic turbine and its governing system
Yang Dexian, Sun Shuxin, Li Guojiu
(Huazhong University of Science and Technology)
Abstract This paper analyzes the dynamic characteristics of the hydraulic turbine and its governing system in the transient process.A new principle is presented for the first time to simulate the characteristics of the hydraulic turbine when the generator operating in various conditions.The results of main modeling links and dynamic simulation test of a closed loop are described in detail.
Key words hydraulic turbine, governing system, characteristics, simulation.
Analysis of stability of channel-governor system in low head hydropower plants
ͺ€ͺ€Song Donghui
(Guangdong Water Conservancy and Electric Power Engineering College)
Abstract The influences of surge in open channel on governor's stability are described in this paper. The formula for discrimination of stability is established.
Key words governor, surge in open channel, dynamic system , Laplace transformation.
New model of stratified laminar flow and drag reduction law in pipe
| Zheng Yonggang | Xie Cuili |
| (Sichuan Union University) | (University of Petroleum) |
Abstract A new model of stratified laminar flow in pipe is proposed and the velocity distribution laws of stratified flow in pipe are studied. The analytical correlation of velocity field is obtained by using this model. The flow resistance law of stratified flow is investigated. The results provide the theoretical base of drag reduction by aeration in stratified flow. The calculating results show that aeration in stratified flow can achieve effective drag reduction.
Key words pipe, stratified flow, Newtonian fluid, drag reduction.
Study on the mechanism of concrete destruction under frost action
Li Jinyu, Xu Wenyu, Cao Jianguo, Lin Li, Guan Yushi
(China Institute of Water Resources and Hydropower Research)
Abstract In this paper, the changes of macro properties of concrete under frost action are studied. The micro structures are studied by means of mercury pressure porosimeter, DTA and SEM. The results show that the destruction mechanism in different concrete are in different types.
Key words Air-Entraining, non-air- entraining, concrete, frost resistance, strength, water absorption rate, pore structure, micro structure.
Seismic response analysis of aqueduct bridge with laminated rubber bearing
ͺ€ͺ€Zhang Junfa, Liu Yunhe, Wang Kecheng
(Xian University of Technology)
Abstract In this paper, seismic response of an aqueduct bridge with super structure isolation using RB(Laminated Rubber Bearing) or Teflon RB is investigated by using nonlinear step-by-step integration procedure. The comparison of computational data for three bearing cases shows that RB or Teflon RB is very effective in controlling the seismic response and some useful results are obtained for design of aqueduct bridge.
Key words aqueduct bridge, laminated rubber bearing, non-linearity, seismic response analysis.
The
stability analysis for the slope of upper reservoir in Shisanling
Pumped Storage Project
Zhou Xiaoguang, Chao Huayi, Cui Yihao
(China Institute of Water Resources and Hydropower Research)
Abstract Based on the deterministic model and the probabilistic mode l, the geotechnical properties of the weathered andesite material used in the u p per reservoir of Shisanling Pumped Storage roject have been investigated. According to the satistics, the stability and reliability of the slope have been analyzed.
Key words concrete face slab, rockfill, slope, stability analysis.
Grey markovian model for predicting annual maximum stage
Dong Sheng, Liu Defu
(Ocean University of Qingdao)
Abstract This paper combines Grey system with Markov theory to present a high precision model Grey Markovian model, which is used to forecast extreme water level. Examples show that results of the annual maximum stage calculation are found to be in good agreement with the measured data. In addition, a new method to solve GM(1,1) is also obtained in this paper. The precision is also improved.
Key words Grey Markovian model, forecast, annual maximum stage.
Discussion on problems of BP neural networks applied to hydrological prediction
ͺ€Liu Guodong, Ding Jing
(Sichuan Union University)
Abstract In this paper, the effect of the complexity of training data on the determination of the network structure is investigated. Some measures a re employed to accelerate the network training. The results of two practical pre diction cases indicate that the BP neural network is better than other models such as some regression models.
Key words BP networks, hydrological prediction, training algorithm.
Hydraulic capture technique for remedy of ground water
contaminated by petroleum and its numerical model
| Xu Shaohui | Zhu Xueyu |
(Nanjing Institute of Soil Science, Chinese Academic of Science) |
(Nanjing University) |
Abstract The temporal and spatial distributions of petroleum contaminants in ground water are dealt with in this paper. On this basis, hydraulic capture engineering is arranged. The results from running the hydraulic capture wells show the partial petroleum contaminants in groundwater maybe removed out by the hydraulic capture technique. The transport of contaminants during running the hydraulic capture wells is modeled as well. Specially, the temporal and spatial distribution of petroleum contaminants in ground water before and after cut the contaminant sources off is predicted. At last, the conclusions can be come to a s follows: 1.The prerequisite of arranging remedial engineering is to ascertain the hydrogeological conditions in studied region, 2.The capture zone is an efficient method for the remedy of contaminated fracture-karst water.
Key words groundwater, petroleum contamination, hydraulic capture, numerical modeling.
Application of graphics theory and GRG method to optimal
design of pipe network
| Zhang Fengzhou |
| (Henan Administration Bureau of Yellow River) |
| Shi Ji |
| (Dagang Design Institute of Oil Field) |
| Wei Yongyao |
| (Wuhan University of Hydraulic and Electric Engineering) |
Abstract In this paper graphics theory is applied to the optimization of network design with GRG method. The design of the Hanyang district pipe net work of Wuhan city is optimized with GRG algorithm, and the calculated pipe diameters are standardized by using linear programming.
Key words general reduced gradient, graphics theory, pressure pipe network, optimal design.