Journal of Hydraulic Engineering No.05 1999 |
CONTENTS [Chinese] |
Interpretation of vertical sediment distribution in terms of perturbation theory |
Ni Jinren |
(department Urban ＆ Environmental Sciences, Peking University) |
Zhou Donghuo |
(American KEANE Co.Ltd) |
Abstract Within the framework of two-phase flow theory,an analysis is carried out based on the momentum and continuity equations of fluid mechanics.Corresponding to the physical process of the interaction of the solid and fluid phases,a perturbation analysis is systematically developed.Consequently,the generalized suspended sediment concentration profile suggested by Ni (1989) is derived directly from the basic governing equations.The obtained concentration profile has wider range of application than the well known Rouse formula.
Key words sediment,soild-liquid two-phase flow,perturbation theory.
Numerical simulation of turbulent buoyant flow in natural open channel
Part I: Segregated Methood for 3-D complicated boundary treatment
Hao Ruixia |
(China Institute of Water Resources and Hydropower Research) |
Zhou Lixing |
(Tsinghua University) |
Abstract A generalized software 3TBF has been developed for the numerical simulation of 3-D buoyant flows.A buoyancy-modified k-εturbulent model is adopted to close the Reynolds equations and the Segregated Method is applied for the first time to treat 3-D complicated boundary in accordance with SIMPLE algorithm.The model has the ability not only to reflect the buoyancy effect induced by density difference between cooled water and natural water,but also to simulate the thermo-hydraulic behavior of natural open channel flows.This paper is the first part of the study.It describes some skills of Segregated Method in 3-D complicated boundary treatment.
Key words segregated method,3-D complicated boundary,turbulence model,SIMPLE algorithm.
EVALUATION SYSTEM OF SUSTAINBLE DVELOPMENT IN DU JIANG YAN IRRIGATION AREA
Wang Huimin,Xu Ming,Fang Lerun |
Xiao Fan |
(Hohai University) |
(Du Jiang Yan Management Bureau) |
Abstract Based on the principle of sustainable development of water resource restrain in irrigation area, the paper established the evaluation index system of sustainable development in Dujiangyan irrigation area. An integration evaluation method combining static and dynamic method is proposed. By using this method, the sustainable development of the irrigation area is evaluated comprehensively.
Key words sustainable development, evaluation system, index system, Dujiangyan irrigation area.
Jiang Shuhai |
(Nanjing Hydraule Research Institute) |
Abstract In this article, the design standard for flood prevention and its effect on the safety of dam are discussed. The event tree method is applied to analyze the formation procedure of the dam failure due to overtopping and the risk rate for flood prevention can be calculated quantitatively. The design standards of the existing dams have been checked. Thus, the reasonable principle and method for determination of the design standard are demonstrated.
Key words design standard, flood prevention, random and fuzzy risk assessment, dam safety, allowable risk level.
Qian Yusen，Li Zhanjun，Zhong Yifang，Luo Hongzhi，Liu Jibin |
(Huazhong University of Science and Technology) |
Abstract Features of reinforcing design are discussed. A scheme of 3-D visual reinforcing CAD system is presented and techniques for implementation are studied. A case study is given.
Key words reinforced concrete, reinforcing scheme, hydraulic structure, 3-D CAD.
| Structural reliability analysis in original random spaceGong |
| Gong Jinxin,Zhao Guofan |
(Dalian University of Technology) |
Abstract A method for structural reliability analysis in orginal space is presented in this paper. In this method the non normal random variables are not necessary to transfer or map into normal random variables. It is convenient to use in some situations wherein the probability distribution function of random variable is implicit. The failure probability formulas are derived based on the first order and second order expansion of performance function at the point that maximize the loglikelihood. The validity of the presented method is demonstrated by three examples.
Key words structures, reliability, original space, non normal random variable.
On the compressibility criterion of high velocity aerated flows |
Zhao Jianfu |
(Institute of Mechanics,Chinese Academy of Sciences) |
Li Wei |
(Wuhan University of Hydraulic and Electric Engineering) |
Abstract The fundamental equation of high velocity aerated flows are deduced by using the two-fluid continuum model.The compresibility criterion is studied using the analysis of magnitude order of the equations mentioned.It is shown that the compressibility effect depends on the adiabatic Mach number The flow can be referred to incompressible if M＜0.3,while the effect of compressibility should be considered if M is higher than 0.3.
Key words aerated flow, compressibility criterion,Mach number.
| Ma fuxi | Li Wenxin |
| (North China Institute of Water Conservancy & Hydroelectric Power) | (Peking University) |
Abstract A 2-D mathematical model for sediment transport in estuary is established. In the model, a partial cell parameter is introduced for treating irregular boundary and the Alternating Direction Implicit Method(ADI)algorithm is used for calculating the equations of sediment transport. The wind action and the effect of radiation stress of waves on current and sedimentation are taken into account. The computational results are in close agreement with field observation and remote sensing data.
Key words radiation stress of waves, irregular boundary, partial cell parameter, sediment, deformation of the river bed.
The numerical simulation of hydraulic jump downstream of the sluices |
Yuan Xinming，Mao Genghai，Wu Shourong，Tang Jinchun |
(Zhejiang University) |
Abstract The hydraulic jump downstream of the sluices are simulated by using k ε turbulence flow model. The Volume of Fluid(VOF) method is applied. The results of computation are in good agreement with the experimental data and satisfactorily describe the flow field.
Key words turbulence flow model, outflow from sluice and weir, free surface, aerated flow.
Time dependent reliability of concrete gravity dam affected byrandom thermal creep stress |
Liu Ning |
(Hohai University) |
Liu Guangting |
(Tsinghua University) |
Abstract In this paper, the random properties of both the thermal creep stress and strength parameters of concrete are taken into account in the calculation of time dependent reliability. Stochastic Finite Element Method is applied in Conneetion with numerical method for calculating time dependent reliability. By simulating the construction procedure, time dependent reliability of a typical concrete gravity dam is calculated.
Key words time dependent reliability, stochastic finite element method, gravity dam, concrete.
Huang Qiang，Wang Zhengfa，Chang Jianxia，Liang Zhu，Tian Fengwei |
(Xian University of Technology) |
Abstract Based on principle and methods of system science,the multi-objective joint optimal operation models for municipal water supply is established.The structure of multi-objective model is investigated and the method for solving multi-objective model is proposed.The optimal operation of water supply for Xi'an city is analyzed and computed as a case study.
Key words city, water supply, optimal operation, multi-purpose, large scale system, model.
Lu Dingyan |
(Huzhou Water Management and Hydropower Adiministration) |
Abstract Dou zone is the area located at river side and surrounded by levee. The origination, formation, evolution and characteristics of Dou zone are investigated. The differences among Dou zone, Xu zone and reservoirs are didntified.
Key words Dou zone, Xu zone, Tai Lake basin, hilly district, river side, city construction method.
Analysis on forebay water level depression duringstarting of pump station |
Song Yueqing，Lin Ren |
(Shandong Provincial Survey and design Institute of Water Conservancy) |
Abstract In this paper the relations among pump head, discharge and rotational speed are discussed and the characteristic value of pumping equipment system as well as the flow pattern in forebay are analyzed during the starting of pump station. On this basis, a method for calculating the water level depression of forebay is proposed.
Key words pump starting, characteristics, pump system, forebay, flow pattern, water level depression.
Study on some theoretical problems in water saving irrigation of forage grass |
Guo Kezhen，He Jingli |
(Water Conservancy Research Institute for Pastoral Area) |
Abstract Based on the study on the evolution process of drought resistance of herbage.from view points of physiological and ecological aspects,and the ecconomical water consumption of herbage in arid/semiarid area,this paper proposed the method for optimal decision making of water saving regimes.
Key words herbage drought-resistance mechanism,economical consumption,water saving irrigation