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Yu Guoliang Fang Duo |
(Sichuan University) |
Ao Ruzhuang Zheng Binhui |
(Environment Research Institute of China) |
Abstract Research work on bed resistance of alluvial channel is reviewed andthe popular law of bed resistance given by Engelund-Fredsoe(1982) is checked using data in this study.Based on the analysis on data from 2261 sets of flume experiments and 592 sets of field observation,a new formula for bed resistance is proposed.
Key words bed resistance,grain resistance,bed form resistance,alluvial channel,roughness.
Zhao Jianfu |
(Institute of Mechanics,Chinese Academy of Sciences) |
Li Wei |
(Wuhan University of Hydraulic and Electric Engineering) |
Abstract The homogeneous adiabatic theory for compressible shock wave in extra high velocity aerated flow and the homogeneous theory for incompressible hydraulic jump and oblique shock wave in supercritical aerated flow are introduced in this paper.The comparison of the predications for the flow in the vicinity of an abrupt wall deflection by compressible and incompressible theory is made and remarkable difference is found.A discriminant for identification of the existence of compressible effect in extra high velocity aerated flow is suggested.
Key words aerated flow,compressibility,shock wave,supercrticial flow.
Wang Zhengzhong |
(Northwest Agriculture University) |
Yuan Si |
(Tsing hau University) |
Wu Chenglie |
(Water Conservancy Bureau of Shanxi Province) |
Abstract On the basis of previous studies,this paper presents two approximate formulas for calculating the crtical water depth of trapezoidal channel.This method has the advantages of high precision,applicable to a large range and simplicity.
Key words trapezoidal channel,crtical water depth,caluclation formula.
The realization of multimedia dynamic simulation system in 2 D flow field |
Wang Xuejun Li Yueyong Yang Jinliang |
(Tianjin University) |
Zhang Huaqing |
(Water Transport Engineering Research Institute, Ministry of Communication) |
Abstract This paper presents a multimedia dynamic simulation system of 2 D flow field established in a computer. The mathematical model is established and problems such as the conversion of flow field from Euler system of Lagrange system, the rotation of pixels, continuity of fluid field as well as the synchronization of background music and commendatory are solved according to the computer graphics and multimedia theory. A technique of coding is adopted to compress the image file. The system simulates the movement of the fluid under different schemes in Haihe estuary vividly.
Key words simulation, 2 D flow field, computer graphology, orthogonal curvilinear meshes, bitmap, multimedia.
Tang Guangmin |
(Anhui Water Resources Research Institute) |
Abstract Based on the experiment for drainage index regarding the continuous days of water logging and excessive soil water,the solution for continuous stress-day index(CSDI) and weight coefficient of water logging(CW) are proposed and the relationship between relative crop yield and CSDI is established.The study results show that the utilization of CSDI is reasonable in determination of drainage standard.
Key words continuous stress-day index of water logging and excessive soil water, weight coefficient of waterlogging, drainage standard, experimental study.
Study on technical parameters of buried pipe system for salt leaching in beach area |
Zhang Zhanyu Guo Xiangping |
(Hohai University) |
Tang Jianxi |
(Water Conservancy Bureau of Jiangsu Province) |
Qiao Baoyu Su Jie |
(Water Conservancy Bureau of Sheyang County) |
Abstract Based on the soil-salt transfer theory and the soil-water dynamics theory,the design methods of buried pipe drainage engineering for improving saline land in beach area are proposed.The buried depth,dimensions and distance between pipes under the condition of different desalinization standard are also provided.
Key words buried pipe engineering,desalinization standard,salt leaching,rice planting.
On the design method for large reinforced concrete aqueductwith multi longitudinal beam |
Zhao Shunbo Li Xiaoke Zhao Ping |
(North China Institute of Water Conservancy and Hydropower) |
Abstract In this paper, a modified 3 D rigid frame method for calculation of internal force in the main section of the beam is proposed. The stress distribution is checked using 3 D concrete finite element method. The calculation result is in good agreement with the experimental data.
Key words reinforced concrete, aqueduct, internal force, stress.
Wu Hegao Qin Jizhang Gong Guozhi Ma Shanding |
(Wuhan University of Hydraulic and Electric Engineering) |
Abstract A Study on the structure of girderless trifurcation is carried out by means of classical mathematics, 3 D finite element method and model test. The results show that the stell lining reinforced concrete girderless trifurcation, comparing with the exposed steel girderless trifurcation, has the advantages of less plate thickness, easy to construct, higher safety and lower cost.
Key words girderless trifurcation, steel lining reinforced concrete structure, 3 D FEM, model test.
Qin Rong |
(Guangxi University) |
Abstract Based on the variation principle and spline function, the Spline Finite Point Method is suggested. The calculation format according to the analysis method for thick shell and 3 d elastic structure is established in consideration of the interaction between the dam and finite foundation as well as infinite foundation. Examples are also given.
Key words analysis of arch dam, Spline Function Method, Spline Finite Point Method.
Disturbance attenuation approach for design of water turbine governors |
Liu Yongqian Ye Luqing |
(Huazhong University of Science and Technology) |
Tong Songlin |
(Northwest University) |
Abstract The Disturbance Attenuation Approach(DAA) of H∞-Control theory is applied to the design of the governors of water turbines.This method can be used in both linear and nonlinear contol system.The designed closed hydraulic turbine regulating system is robustly stable,and the disturbances acting on the system can be effectively attenuated.The simulation results of a turbine regulating system show that the method presented is effective.
Key words turbine regulating system, speed governor, H∞ Control, disturbance attenuation approach.
Tang Yi |
(Zhejiang Design Institute of Water Conservancy and Hydroelectric Power) |
Wu Chigong |
(Sichuan Union University) |
Zhou Zhu |
(Xinjiang Agricultural University) |
Abstract The flow field in the funnel sluice is studied by numerical simulation and verified by a model test.The finite-difference procedure of the N-S equation based on the boundary-fitted curvilinear coordinates is employed in the numerical simulation of the 3-D flow in the funnel sluice and the covariant velocity components are chosen as independent variables.In the model test,the distributions of mean velocities are measured by using LDV.The computational results are well accord with the experimental data.
Key words funnel sluice, screw flow, covariant velocity, LDV, distribution of mean velocity.
Comparison of different methods for evaluating Alkali reactivity of aggregate |
Wang Aiqin Zhang Chengzhi Wang Xiujun Ma Fengling |
(China Institute of Water Resources and Hydropower Research) |
Abstract The alkali reactivity of the aggregates from three quarries is evaluated by using different testing methods. The causes of the discrepancy of the results derived from different methods are investigated. On this basis, comments on evaluation method is suggested.
Key words aggregate, alkali reactivity, evaluation method.
Tu Chuanlin Jin Shuangquan Lu Zhongming |
(Mid South Design and Research Institute for Hydroelectric Projects) |
Abstract The characteristics of RCC including the compressive strength, tensile strength, heat and deformation are investigated experimentally. The feasibility of the adoption of RCC for Longtan gravity dam 200m. high is demonstrated.
Key words RCC, characteristics, gravity high dam.
Study on velocity distribution function of river cross section |
Chen Senlin |
(Wuhan University of Hydraulic and Electric Engineering) |
Xiao Ge Zhao Yunfa Zhang Jinshun Wang Wenjun |
(Gezhouba Hydraulic Power Station) |
Abstract This paper analyzes the factors influencing the distribution of canal or river cross section and formulates the empirical exponential function which can reflect flow characteristics and shape of river cross section. The parameter calibration method and velocity forecasting function are proposed. The successful application to river closure of the Three Gorges Project indicates that the accuracy of this method is fairly high.
Key words river cross section, velocity distribution function, parameter calibration, simulation, velocity forecasting.
Stochastic analysis of spatial variability for variables of unsaturated flow |
Huang Guanhua |
(China Agricultural University) |
Abstract The data of tension head collected from field site have been analyzed with statistical method. The result shows that the spatial structure of capillary tension head can be characterized by linear semivariogram model with the mean of capillary tension head as its variable. According to the statistical distributions from experimental data the analytical expressions of capillary tension head are derived with small perturbation method. Both experimental data and analytical expression indicate that variance of capillary tension head is a quadratic function and increases with its means. The comparison of analytical variance against the experimental data indicates that the analytical result is larger than the experimental result.
Key words unsaturated flow, capillary tension head, spatial variability, variance, stochastic analysis.
