3-D mathematical model for flow in river bend
in body-fitted curvilinear system
HUA Zulin |
(College of Water Resources & Environment, Hohai University) |
Abstract A 3-D mathematical model in body-fitted curvilinear grid system, that conforms to the characteristic of flow in river bend is established. The k ε turbulence model is applied to simulate the flow detail. The availability of the model is examined by the calculation of the flow in a river bend of Yangtze River. The results show that the model is effective and satisfied。
Key words curvilinear coordinate system；river bend;3-D flow；mathematical model.
Effects of sprinkler uniformity on spatial variability
of soil moisture and winter wheat yield
LI Jiusheng RAO Minjie |
(Agrometeorology Institute,Chinese Academy of Agricultural Sciences；2.China Institute of Water Resources and Hydro Power Research) |
Abstract Sprinkler water distributions both below and above the crop canopy,soil moisture,leaf area index and yield were measured during an irrgation season of winter wheat to determine their spatial structures and statistical functions.The experimental results demonstrate that the correlative ranges of cumulative water application during the irrigation season and crop yield are about 5m and 7～10m respectively.No spatial structure is found for leaf area index.Cumulative water application,leaf area index and crop yield can be represented by a normal distribtuion function.Christiansen uniformity coefficients for water storage were always greater than 90% though the sprinker uniformities varied in the range of 57% to 89% during the irrigation season.
Key words sprinkler irrigation;uniformity coefficient;soil moisture;yield; spatial structure.
FENG Jingchun |
college of International Industry and Commerce Hohai University |
Abstract Based on the analysis of the specialties of water and hydropower projects and project management,the limitations of the application of traditional behaviour controul methods are found out.A grey swinging model is proposed and the procedure for establishing the model, parameter determination and validity verification are investigated in detail. The stability of the behaviour controul sysytem is analyzed and the judgement standards for development situation are established.
key words behaviour controul system; swinging model; grey system.
Application of fuzzy artificial neural network to observation
data analysis of earth dam monitoring
CHEN Jiguang,LU Xuechang |
(Shandong University of Technology；Shandong Architectural and Engineering Institute) |
Abstract A fuzzy artificial neural network method for analyzing the observation data of earth dam monitoring is presented in this paper. The fuzzy relationships between the displacement and various factors are discussed. This method can be applied to the prediction of dam deformation.
Key words fuzzy relationship, fuzzy artificial neural network, prediction of dam deformation.
The effect of water supply patterns on non hydraulic root signal and water
use efficiency of spring wheat
LI Fengmin WANG Jun GUO Anhong |
(Lanzhou University) |
Abstract In this paer, the experimental results of the influence of water supply at various soil depth on non hydraulic root signal and water use efficiency are presented. Two genotypes of spring wheat and three soil moisture regimes are adopted. Plants are grown in cylinder pots outdoor. The analysis on experimental data shows that frequent irrigation on topsoil after sowing results in low water efficiency, while irrigation with equal amount of water just before sowing will elevate the water use efficiency.
Key words drought, irigation, spring wheat, root signal, yield, water use efficiency.
Study on fundamental performance of pulsed liquid jet pump
GAO Chuanchang |
(North China Institute of Water Conservancy and hydroelectric Power) |
Abstract Based on the momentum and energy equations of the pulsed liquid, the fundamental performance equation of the pulsed liquid jet pump is derived and compared with the equation for steady liquid jet pump. According to the experimental data of the time averaged performance and the geometric size of the pulsed liquid jet pump, an empirical formula for the fundamental performance of this kind of pump is proposed.
Key words pulsed liquid; momentum equation; energy equation; jet pump; fundamental performance; empirical formula.
Study on random seismic analysis method for gravity dam
HE Yunlong, LU Shuyuan |
(Wuhan University of Hydraulic and Electric Engineering) |
Abstract In this paper, the earthquake movement of the dam foundation and dynamic response of structures are simulated as stochastic process and the seismic response of gravity dam is studied by random vibration theory. A practical model for earthquake movement input is proposed and the method for random seismic analysis of gravity dam is discussed.
Key words gravity dam; earthquake movement; stochastic process; random vibration; seismic response.
Deformation prediction of deep excavation and
its information-feedback construction
LI Qinglai, XIE Kanghe, ZENG Guoxi |
(Shanghai Tunnel Engineering & Rail Transit Design and Research Institute,Zhejiang University) |
Abstract A neural network for nonlinear prediction nad the Bayes Discrimination Analysis Method for checking the geo-environmental stability in deep excavation are proposed in this paper. A software(DEIFC,version 1.0)for information-feedback construction is implemented in Borland C+ +5.0.Two deep excavation cases in Hangzhou are used to demonstrate the capability and practicality of this software.
Key words deep excavation; deformation; information-feedback construction; geo-environmental problem.
Analysis on Dynamic mechanism of sediment winnowing caused by wave
CAO Wenhong, LIU Qingquan |
(China
Institute of Water Resources and Hydropower Research, |
Abstract In this paper,a systematic study on dynamic mechanism of sediment particles being winnowed from seaded by wave action is carried out.An equation for sediment winnowing caused by wave is established.The calculated results are in good agreement with the measured data in the Yellow River estuary。
Key words sediment particle; sediment winnowing; wave action; dynamic mechanism.
Seismic sliding stability analysis of a flat-slab buttress dam
LIU Guoming |
(Fuzhou University) |
Abstract Seismic sliding stability of the Gutianxi third cascade buttress dam is studied with 3-D non-linear FEM in this paper. The contact non-linearity between the dam and its foundation is simulated. The rock and concrete are assumed to be linearly elastic and the infinite area of water body and foundation are simulated with infinite elements. The sliding factor is obtained with static analysis method and the relevant FEM program is developed. By using this program, the variation of sliding factor of the dam with time under longitudinal earthquake motion is attained.
Key words Buttress dam; seismic sliding stability; nonlinear FEM; contact.
Large vortex structures and their characteristics of
submerged impinging jet in plunge pool
LIU Peiqing, LI Futian |
(Beijing University of aeronautics and Astronautics, China Institute of Water Resourcesand Hydropower Research) |
Abstract The modern turbulence theory is applied to systematic study of the complicated flow mechanism. The quasi-ordering structures of large-scale eddy in the main jet region and turbulent eddy in the wall jet region are analyzed. The origination of fluctuating pressure and the mechanism of energy transfer and dissipation are explained.
Key words plunge pool; complicated flow structure; energy dissipation; mechanism.
3-D turbulence flow simulation for Francis turbine runner
Qi Xueyi, Yang Jianming, Wu Yuling |
(Gansu University; Tsinghua University) |
Abstract This paper presents a practical method for simulation of flow field in Francis turbine runner by applying K-ε turbulence model. Tensor representation of the governing equation under body-fitted curvilinear coordinate system is derived by using Einstein's expressing method. The techniques for selecting control volume and determining the original value of boundary condition are introduced.
Key words turbulence flow model, Franicis runner, numerical simulation, flow field.
Runoff and sediment variations in the upper reaches of Changjiang River
and its tributaries due to deforestation
Xu Jiongxin |
(Institute of Geography,CAS) |
Abstract Based on the long term hydrometric records from the Minjiang River, Jialingjiang River and the upper reaches of Changjiang River, an analysis is made to reveal the effects of deforestation on the hydrological regimes. The results show that forest can significantly elevate the runoff in low-water season and reduce the flood discharge, but its effect of reducing large floods caused by long durating rainstorms covering the whole river basin is limited. The deforestation and slope land cultivation lead to an increase in sediment load, but the interception of sediment by reservoirs built in the river basin makes sediment load decreased. However, the long-term hydrometric record at Yichang Station indicates no trend of changes in sediment load. It seems that it is necessary to adopt not only the reforestation but also the biological and engineering measures to solve the flood and sediment problems in Changjiang River.
Key words hydrological effect, deforestation, runoff, sediment, variation, upper reach of Changjiang River.