• 全国中文核心期刊
  • 中国科技核心期刊
  • 美国工程索引(EI)收录期刊

2002 Vol. 13, No. 1

Display Method:
Numerical study on the effect of vortices upon particle motion in unsteady and unstable liquid-particle two-phase flows
HUANG Yuan-dong, WU Wen-quan, ZHANG Hong-wu, WANG Guang-qian
2002, 13(1): 1-8.
Abstract:
We present a numerical investigation on the two-dimensional liquid-particle two-phase flows passing a circular cylinder at high Reynolds number.Here we apply the discrete vortex method(DVM)to compute the unsteady and unstable water flows,and adopt a Lagrangian approach to simulate the particle motion in flows.We numericaly demonstrate that the definite interrelated structure exists in the particle motion and the vortices in liquid-particle two-phase flows:the motion of intermediate size particles is obviously influenced by the vortices.When water passes a circular cylinder at high Reynolds number,the unstable flow with massive separation is formed,the complicated motion of vortices exists in the wake region.The intermediate size particles are separated from the liquid-particle mixture,then move toward the wake vortex region, finally accumulate in the vortex structures.
Numerical hydraulic modeling visualization system based on software component
ZHOU Zhen-hong, YANG Guo-lu, ZHOU Dong-ru
2002, 13(1): 9-13.
Abstract:
By traditional numerical-hydraulic modeling,the nature of numerical-hydraulic model is hardly revealed. This paper makes a new study for the way in which numerical-hydraulic modeling is carried out, choosing up-to-date component programming model in software project to encapsulate numerical-hydraulic model. In such a way,the visualization in numerical-hydraulic modeling process is implemented. On the other hand,the numerical computation is steered according to the feedback information of visualization.
Water environment models and their modelbase management
LI Ben-gang, TAO Shu, CAO Jun
2002, 13(1): 14-20.
Abstract:
92 water models issued in USA,including surface water mdels,groundwater models and non-point sources models,were analyzed. The general features of the models and their restriction in application were discussed. It is suggested that these models can be efficiently managed using geographical information system and rmdelbase management technology. A framework of such a management system was proposed.
Research on stochastic model of total phosphorus in uniformly mixed system
RAO Qun, RUI Xiao-fang
2002, 13(1): 21-25.
Abstract:
Based on the Vollenweider model,a stochastic eutrophication model was built. The changing process of total phosphorus concentration was regarded as a random process in the model. If the random properties of initial conditions are obtained,the analytical solution as well as the numerical solution can be found. Therefore the model provides the random properties of total phosphorus concentration,such as the mean and variance. The model was calibrated using the results of a rmnitoring program in Geheyan reservoir.
An experimental study of vertical round jets in shallow water
HUAI Wen-xin, NA Yu-tong, HUANG Ji-zhong, TONG Han-yi, JIANG Guo-qiang
2002, 13(1): 26-30.
Abstract:
This paper presents an experimental study of turbulent jets discharged vertically through a single circular submerged pipe into a large of stagnant non stratified water of finite depth. The experiments were carried out in the laboratory facilit ies consisting of a closed system capable of maintaining steady state conditions. The maximum water surface elevation is obtained for numerous flows,as function of jet energy flux and discharge depth The similarity of water surface elevation distribution was found,and its formula was got. The distribution of velocity in cross section and the rate of change of centerline velocity were obtained by the micro ADV system.
Application of the genetic algorithm to the gray non-linear programming problems for water environment
QIN Xiao-sheng, ZENG Guang-ming
2002, 13(1): 31-36.
Abstract:
It is a little difficult to solve the gray non-linear programming problems for water environment by normal optimization solutions. The paper tries to use a hybrid numerical algorithm combined with the traditional method and the genetic algorithm to solve the problems. The validity of the method is verified by a practical application.
River flow prediction using artificial neural networks: self-adaptive error back-propagation algorithm
QIN Guang-hua, DING Jing, LIU Guo-dong
2002, 13(1): 37-41.
Abstract:
This paper presents a improved error back-propagation(BP) algorithm,which is named as self-adaptive error BP algorithm. The method includes two strategies:one is adding momentum term at the iterative expressions of the weights,the other is self-adaptive adjustment of the learning rate according to the variety of the sum error. Namely,if the sum error increases,the learning rate will decrease,conversely,the sum error decreases,the learning rate will increases. The learning rate is changed until the sum error has reached a satisfactory level. The improved algorithm can prevent the networks from getting in the part least and can shorten the study time. The self-adaptive error BP algorithm was utilized for predicting river flow of Yangtse River at Yichang station,and satisfactory results were acquired.
Development of generalization module for the reservoir flood-control system
ZHOU Hui-cheng, LIANG Guo-hua, WANG Ben-de, YIN Jun-xian
2002, 13(1): 42-48.
Abstract:
The reservoir flood-control system are successfully designed and developed based on the numerical calculation of reservoir flood-control,the decision-making model of multi-objective fuzzy optimal selection,the decision-making method of man-computer,the Object-Oriented technology and the database technology. The system is a generalized module and interface. For a new reserwir,its flood-control software can quickly be produced as long as the basic data needed by the flood-control reserwir are input.
Development and application of the multi-object and multilevel water demand prediction system
WANG Da-zheng, ZHAO Jian-shi, JIANG Mu-chuan, WENG Wen-bin
2002, 13(1): 49-54.
Abstract:
The paper employs the method of interactive step-up analytic hierarchy process to build drainage basin water demand prediction system,in which the multi-object model is introduced to establish the inter active relationship among the factors including society,economy,environment and water resources. And in this way the multi-object and multilevel structure of water demand prediction system is accomplished. The system is applied to the water resource planning in Haihe River Basin of year 2000.
Modeling soil water retention curve with fractal theory
HUANG Guan-hua, ZHAN Wei-hua
2002, 13(1): 55-60.
Abstract:
A three-dimensional fractal model for soil water retention curve (SWRC) is derived with Menger Sponge model on the basis of Tyler and Wheatcrafts' theory,which is related to the intrinsic nature of the fractal porous structure. The fractal dimension is calculated with experimental data for soil retention curve of ten soils. And the fractal dimension of SWRC is then compared to the fractal dimension of particle-size distribution (PSD) which is calculated on the basis of accumulative mass distribution of soil particles. The resups indicate that the fractal dimension of SWRC increases with clay content but decreases with sand content,and the fractal dimension of SWRC shows slightly different from and is linear related to the fractal dimension of PSD. This implies that the soil water retention curve can be predicted by the powerlaw function incorporating with the mass based fractal dimension of PSD. It can be seen that the predicted soil water retendon curve agrees well with the measured data.
Research on the behavior of fluid flow in a single fracture and its equivalent hydraulic aperture
WANG Yuan, SU Bao-yu
2002, 13(1): 61-68.
Abstract:
Both the aperture and the roughness,which are the two important parameters of a single fracture,are discussed firstly. Research achievements of the fluid flow behavior in a single fracture are systematically reviewed. Various kinds of methods are described,while their rationality and applicability are discussed relatively. Based on the summary of the current achievements,moreover,future development and the possible improvement in the field are briefly discussed.
Numerical simulation of soil water movement under condition of film hole irrigation
Hudan·Tumarbay, Murat
2002, 13(1): 69-73.
Abstract:
Based on theory of soil water dynamics,this paper studies on the soil water movement under condition of film hole irrigation,and develops a two-demension infiltration model for film hole irrigation.The examination of the model shows that the results of numerical simulation of the model are in good agreement with the measured data of film hole irrigation experiment in the field and the model is reliable.
Wick effect and unsaturated soil column test
SHEN Zhen-yao, YANG Zhi-feng, HAN Xin-sheng, NI Shi-wei, YAO Lan-gen, LI Wei-juan, CAI Yun
2002, 13(1): 74-77.
Abstract:
The techniques,especially wick effect one,which were used to construct unsaturated soil column test,are introduced in this paper. The initial research result using wick effect technique in unsaturated soil column is given out. It shows that the wick effect is a very good technique to construct unsaturated soil column test.
Non-linear revision of multiple-time-scale turbulence model and its verification
YUAN Xin-ming, TANG Jin-chun, MAO Gen-hai, WU Shou-rong
2002, 13(1): 78-82.
Abstract:
A nonlinear multiple-time-scale turbulence model is derived by using a nonlinear Reynolds stress formula. The modified model is used to simulate the flow over a backward-facing step by finite volume method,the computed results are wel agreement with the test data and much better than that of the multiple-time-scale turbulence model.
Water content of cloud and its water circulation
ZHANG Xue-wen
2002, 13(1): 83-86.
Abstract:
The calculation and analysis indicte that:(1)The total water content of global cloud is nearly 90×109 t,which is less than 1% comparing with the global vapor.So when calculating the amount of globe atmospheric water,the cloud water content can be ignored;(2)Cumulonimbus is abundant of water,but calculation shows that its precipitable water is less than 3 mm;and(3)There are 1 000 mm water precipitated from the cloud every year,but the precipitable water of cloud is exiguity,so water circulation is very quickly.The duration of a water element from the beginning of cloud to landing as rain is less than 2 hours.
Application of the generalized regression neural network to simulating runoff from the mountainous watersheds of inland river basins in the arid area of northwest China
CHEN Ren-sheng, KANG Er-si, ZHANG Ji-shi
2002, 13(1): 87-92.
Abstract:
According to the results of globle changing in the mountainous precipitation and air temperature of Northwest China and supposing possible several conditions of the precipitation and air temperature,this paper uses the generalized regression neural network model to predict the runof of the year 2030. The predicted results show that the runoff may arise to the year 2030,but the arising degree is not large,and ultimately the runof will decrease with arising of the air temperature.
Century’s retrospect and looking into the future of hydrological science
YE Shou-ze, XIA Jun
2002, 13(1): 93-104.
Abstract:
This paper focuses on the issue of the 20-Century's retrospect of hydrological science,and reviews. several important developed stages of hydrological science on hydrological measurements,runoff analysis and calculation,hydrological modeling and forecasting,and main branches of stochastic hydrology, fuzzy hydrology and hydrological system approach. Main problems of present argument,such as the relationships between hydrological science and technology,research and application,and mathematics methods and hydrological physics,are discussed. The paper shows that dilettantism of hydrology in China needs to be attendon. There are opportunities and challenges on hydrological science in the 21-Century of China.
Advances and prospects for nonpoint source pollution studies
ZHENG Yi, WANG Xue-jun
2002, 13(1): 105-110.
Abstract:
The basic characters of nonpoint source pollution are summarized in this paper. Major advances in fields of model simulation,landuse,runoff,application of the new technologies and the management are discussed also.In the end,several hot-spots of nonpoint source pollution studies are introduced and the studies and management in China are prospected.
Advances in study on regional water resources carrying capacity and research on its theory
YAO Zhi-jun, WANG Jian-hua, JIANG Dong, CHEN Chuan-you
2002, 13(1): 111-115.
Abstract:
Based on the summarization of research status quo of regional water resources carrying capacity, the paper defines the water resources carrying capacity and expounds its connotation and characteristic.After analyzing the influence factors of the regional water resources carrying capacity,it studies the theory arrangements and explores the theory system of regional water resources carrying capacity.
Advances in study on transport models of multicomponent reacting solutes in groundwater
QIAN Tian-wei, LI Shu-shen, WU Gui-bin
2002, 13(1): 116-121.
Abstract:
The model describing migration behavior of groundwater solutes in porous media can be divided into two parts:the first is the multicomponent aquatic chemistry model,and the second is the hydraulic transport model (advection-dispersion model).This paper presents a short review about two kinds of models aforementioned,mainly introducing the development of transport model of reacting solutes in recent years. In the meantime,some existing problems of the rmdel are also suggested.
Conventional drinking water treatment technologies:existing problems and countermeasures
BAI Xiao-hui, HE Lan-xi, WANG Bao-zhen
2002, 13(1): 122-127.
Abstract:
The pollution status on water sources in China was analyzed. It was stated that there are many problems which can't be solved by conventional drinking water treatment technologies. Based on the concept of safe and high quality drinking water,the development trend of high quality drinking water guideline system was put forward. According to study actuality of advanced treatment technologies of drinking water in the world,it is stated that the advanced adsorption technology,the oxidation technology,the membrane technology and their combination are the rest promising technologies for the advanced treatment of drinking water.
2002, 13(1): 128-129.
Abstract:
2002, 13(1): 130-132.
Abstract: