• 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

2003 Vol. 14, No. 1

Display Method:
3-D numerical simulation of circulating flow in the square cavity
ZHANG Xiu-zhong, WANG Guang-qian
2003, 14(1): 1-8.
Abstract:
A 3-D hydrodynamic model is developed for circulating flow in a square cavity.Based upon the shallow-water equations and by using water depth to scale the vertical coordinate,the governing equations are transformed into the fixed computational domain.A high-resolution finite element scheme is incorporated to rearrange the convective terms,and a semi-implicit solution technique is employed to achieve high efficiency.The rmdel is tested against analytical solutions for the standard cases and used to study flow characteristics of the cavity circulating flow.The numerical results are in good agreement with the analytical and experimental data.The 3-D computation and analysis help to further disclose the flow patterns of the cavity flow,such as the flow behavior of unsteadiness,asymmetry,and unclosedness,the flow structure composed of circulation in both horiwntal and vertical plane,and so on.
2-D open channel flow simulations by the lattice Boltzmann model
CHENG Yong-guang, SUO Li-sheng
2003, 14(1): 9-14.
Abstract:
A special lattice Boltzmann rmdel for simulating 2-D unsteady open channel flows is built by combining the Chapman-Enskog-Expansion derived multi-scale equations that approximate the form of shallow water equations.To verify the model typical 1-D and 2-D dam breaks are simulated,and the results show agreement with analytical method and other models.As an actual example,the unsteady flows in the tailrace channel of a hydropower plant are calculated.
3-D numerical simulation on overbank steady open channel flows in compound channels
HUAI Wen-xin, CHEN Wen-xue, TONG Han-yi, ZHUO Jian-min
2003, 14(1): 15-19.
Abstract:
The Naot-Rodi algebraic turbulence stress model (N-R model) and the hybrid finite analytic method with staged grid are used to predict the behavior of 3-D overbank flow.In order to get the stable convergence solutions,the two kind measures are taken.The first is to use the correctly derivative scheme in non-uniform grid.The second is to use the multi-block matching method.Numerical tests are carried out for an open channel flow with compound section.The detailed results of main velocity contours,second flow distribution in cross section,lateral velocity distribution for relative water depth with 0.46, depth variation of proportions of flow in channel and floodplams are compared with the experimental data.Some quite reasonable results are obtained.It can be shown that the N-R rmdel with hybridfinite analytic method can be used to predict the relationship between water level and discharges for overbank flow.
On velocity response of tracing particles in laser-based velocimetry to complex flows, 1, mathematical model for small particle motion and verification of numerical methods
HUANG She-hua, WEI Qing-ding
2003, 14(1): 20-27.
Abstract:
The application of laser-based velocimetry in experimental researches of flows is closely involved in tracking ability of particles whose density or initial velocity is different from that of fluid.The transient mot ion equation of small particles is analyzed for numerical investigation of particles velocity in response to complicated flow, with particular emphasis on modification of the motion equation at high particle Reynolds number.The mathematical features of part icle transient motion equation are simply clarified and a numerical method to solve it is developed.It is analytically demonstrated that at high particle Reynolds number the particle transient motion equation is a nonlinear integral equation with singularity, while it is simplified to the second Volterra integral equation when particle Reynolds number is smaller than unit.By comparison of the calculat ing results of particle transient motion in uniform flows with corresponding analytical and experimental results, the numerical method is verified to be well valid.
On velocity response of tracing particles in laser based velocimetry to complex flows, 2, numerical analysis of sliding velocity of tracing particles in various flows
HUANG She-hua, WEI Qing-ding
2003, 14(1): 28-35.
Abstract:
Application of the laser-based velocimetry to experimental researches of flows is closely involved in tracking ability of particles whose density or initial velocity is different from that of fluid.Based on the non-dimensional particle transient motion equation for high particle Reynolds number, a concept of velocity of small particles in response to arbitrary flows are pre sented and described mathematically.In various typical flows, the particle's transient motions are investigated numerically, and the effects of several parameters, such as particle diameter and density, on particle's velocity in responses to flows are analyzed quantitatively.
Nonlinear study on transport rate of bedload
YANG Ju-rui, FANG Duo, HE Wen-she, LIU Xing-nian
2003, 14(1): 36-40.
Abstract:
The cusp-catastrophe theory of nonlinear science is applied for studying transport rate of bed load in this paper.By means of analyzing the factors effecting incipient motion of sediment, the state variable and the bound variable in cusp-catastrophe model are obtained, and the cusp-catastrophe model being able to reflect the transport of bed load is built Based on the standard equation of the cusp-catastrophe, the function between the bed load intensity Φ and Shields number Θ is derived by using coordinate transform and topology transform.The bed load intensity Φ is regarded as the state variable, and Shields number and coefficient of condensing of bed material m are regarded as bound variable in cusp-catastrophe model.Flume experiment data and other formulas are used to verify the cusp-catastrophe model, it indicates that the results calculated from the cusp-catastrophe formula agree well with the flume experiment data and the results calculated by other formulas.This indicates that the cusp-catastrophe formula derived here is reasonable, and the results can reflect the characterist ics of transport of non-uniform sediment.The purpose of this paper is to explore the incipient motion and transport laws of non-uniform sediment from the viewpoint of nonlinear theoty.
Calculation method for the topographic index in TOPMODEL
KONG Fan-zhe, RUI Xiao-fang
2003, 14(1): 41-45.
Abstract:
The topographic index, ln(α/tanβ), is an important parameter of many physically based hydrological models.The TOPMODEL is based on the calculation of ln(α/tanβ) index and its distribution.In terms of a digital elevation model (DEM), α is the cumulative upslope area draining through per contour length to a pixel, which reflects the tendency of water to accumulate at any point in the catchment, tanβ is the local slope angle of the cell, which reflects the tendency for gravitational forces to move that water downslide.The calculation method for ln (α/tanβ) index widely used is the multiple flow direction algorithm developed by Quinn et al (1991).It follows that, in the algorithm, the contour length normal to the direction of flow flowing out the current cell is used to determine both α and tanβ, and that the calculated total cumulative contributing area of downslide grid cell does not include the area of the current cell.These are unreasonable.It is found that the contour length used to determine α should be that normal to the direction of flow entering into the current cell, rather than that flow out the current cell.The improved algorithm calculating the ln(α/tanβ) index is presented, in which the area of the current cell is included in the calculated total cumulative contributing area of downslide grid cell.The different between the results of the two algorithms is described.
Study on characteristic of the absorption and scattering coefficients of Taihu Lake waters
YU Hong, CAI Qi-ming, WU Jing-lu
2003, 14(1): 46-49.
Abstract:
The optical property of water body is the foundation of research on limnological hydrooptics.In this paper,the absorption and scattering coefficients of Taihu Lake waters both in winter and summer are calculated by using the parameterized model of the hydrooptical property.Moreover, the classification of the optical types of the waters is also carried out.The resups show that Taihu Lake in winter appears to be of water type PY with suspended particles and yellow substence being the dominant light absorbers,and in summer of water type CPY,with suspended particles, yellow substance and phytoplankton algae being the dominant light absorbers.Upon this,whether in winter or in summer,unpigmented suspension has the main effect on the scattering property of Taihu Lake waters.
Stable oxygen isotope in water mediums in Urumqi River basin
ZHANG Xin-ping, YAO Tan-dong, TIAN Li-de, LIU Jin-miao
2003, 14(1): 50-56.
Abstract:
The variations of stable oxgen isotopic in different water mediums are analyzed for the period of sampling using the data in precipitation,surface firn,glacier melt water and stream water sampling in Urumqi River basin.It reveals that there is marked temperature effect on stable oxygen isotope in precipitation,and the effect relates to the altitude.Fbwever,no marked altitude effect is found in the surface firn and the glacier melt water;the stable oxygen isotopic ratios in glacier melt water are all lower than those in stream water.Furthermore,the impact degree of different factors on the variations of stable oxygen isotope in the process of water cycle and their interaction are evaluated in the study,which pnwides an example for the application of stable isotopic technique to the study on water cycle.
Application of the environment isotope method to study on the leakage passage in foundation of Beijiang Dyke Shijiao section
CHEN Jian-sheng, DONG Hai-zhou, CHEN Liang
2003, 14(1): 57-61.
Abstract:
The Environment isotope method and the artificial tracer method were used to investigate the reason of "piping" in Beijiang Dyke Shijiao section.According to the stable istope analysis of Deuterium and Oxygen-18 from the water samples during the flood sewn,the "piping" water origin was approved.Combining with the artificial tracer method,the leakage passage in the bedrock fault was determined finally.All results are very important to the next reinforcing the dyke work.
Abnormal characteristics analysis of groundwater temperature field in canyon areas
ZHOU Zhi-fang, WANG Jin-guo
2003, 14(1): 62-66.
Abstract:
The groundwater temperature field shows some abnormal phenomena due to special topographic and geormrphic conditions and geologic characteristics in canyon areas.Taking groundwater temperature field in canyon areas at Xiluodu hydroplant as an example,the groundwater temperature field is analyzed systematically through the numerical simulation,the analogy and the regression analysis method.And then,the abnormal mechanism of groundwater temperature field in canyon areas is discussed.From the examples analysis,it is concluded that as region groundwater flow in deep circulation is warmed through deep parts,the abnormity of the groundwater temperature in Xiluodu canyon areas is normal phenomena displayed in drainage region.It is not made by active tectonics.Therefore,the dam location selected in here is feasible.
Solution to 3-D unsteady saturated-unsaturated seepage problem and accurate treatment of saturated and unsaturated exit surfaces of seepage
ZHU Yue-ming, GONG Dao-yong
2003, 14(1): 67-71.
Abstract:
A numerical procedure for finite element method solution to 3-D steady and unsteady,saturated unsaturated seepage problems is thoroughly presented in the paper.At the same time among the descriptions of the seepage boundary condidons,the correct mathematical expression of the unsteady exit surface of seepage is also established.In order theoretically accurately to describe the conditions of the unsaturated exit surfaces and to develop a strict numerical technique for simulating them,two new definitions of extreme moisture content and coefficient of water evaporation on unsaturated exit surface are originally given on the basis of the natural coherent physical properties of seepage media.Since the exact locations of the seepage exit lines between the saturated and unsaturated seepage areas couldn't be known at the beginning,a new solution concept and procedure are proposed.They use the transformation of the boundary condition types of the saturated and unsaturated exit sur faces during the numerical iterations according to the middle solutions to the problem.The location of the exit line of seepage can accurately be identified and the two-type exit surfaces be treated in detail.Therefore,the thought of accurate numerical treatment of saturated and unsaturated exit surfaces is implemented for the first time.Theoretically the problems of steadyunstea即and saturated-unsaturated seepage fields are solved thoroughly and rigorously.
Two-Region model for solute transport through heterogeneous soils and calculation of the analytical solution
ZHANG De-Sheng, SHEN Bing, SHEN Jin, WANG Quan-jiu
2003, 14(1): 72-78.
Abstract:
A two-region model for 1-D solute transport through heterogeneous soils considering scale-dependent dispersion is studied, and an analytical solution describing the concentration distribution in the mobile region and immobile region is deduced under the initial concentration zero and a constant flux boundary condition of a semi-infinite 1-D space.The numerical computation is completed by the Mathematica software package.
PCB biodegradation in constructed wetland and contamination risk analysis
LIU Ling, LU Gui-hua
2003, 14(1): 79-84.
Abstract:
PCB biodegradation in constructed wetland could be described quantitatively with a mathematical model,which was established considering the sorption/desorption,sequestration,diffusion and biodegradation processes.The rmdel simulations were performed in this paper to predict the PCBs' degradation behavior,the necessary treatment time and the end point.Using the Monte-Carlo simulation techniques,the contamination risk analysis for PCB biodegradation in constructed wetland was conducted.It is noteworthy that,after 8 years' biodegradation,no less than 69.4% 4-Cl-PCBs in soil would have been degraded wrath 75% probability and no greater than 10.9% 4-Cl-PCBs in soil would continue to contaminate bulk water wrath 75% probability.The necessary treatment time for 4-Cl-PCBs to reach the end point in soil is no greater than 16.20 years wrath 75% probability,and the sequestration part in soil is no greater than 20.9% with 75% poobaility.
Predicting of temporal-spatial change of groundwater table resulted from current land use in Minqin oasis
MA Xing-wang, LI Bao-guo, WU Chun-rong, PENG Hong-jia, GUO You-zhen
2003, 14(1): 85-90.
Abstract:
The paper combines GIS and the FEFL.OW sofware,a special software modeling groundwater flow with finite element method,to rmdel groundwater flow affected by current land use in Minqin oasis,Gansu province,China.The results show that the current land use mode would result in rapidly descending of groundwater table in the oasis.There wauld be two groundwater funnels in the oasis in 2010,and the funnel centers would be located at center of the oasis,the groundwater table in funnel centers wauld be 47 to 52 m,and the groundwater in oasis wauld be table 9 to 34 m deeper than it in 1997.The analysis shows that if the current land use is kept,the groundwater would gradually be used up and sped up desertification in Minqin oasis in the condition of water amount fixedness or decreasing of upper reaches;on the other hand,if the crop cultivation structure is adjusted and the watersaving technologies are extended,the groundwater pumping amount would be decreased and the descending of groundwater table wauld be slowed.
Atmospheric hydrologic cycle over the Qilian-Heihe Valley
WANG Ke-li, CHENG Guo-dong, JIANG Hao, ZHANG Li-jie
2003, 14(1): 91-97.
Abstract:
The atmospheric hydrologic cycle over the Qilian-Heihe Valley are analyzed by using the observed data of meteorological stations and the NCEP/NCAR monthly mean data from 1958 to 1997.Some significant results are showed.The sparse water vapor source is reason one of little water vapor in atrmsphere over the Valley,and the water vaporflux divergence is reason two of that.The higher precipitation efficiency and less evaporation are prone to accumulate water substance into runoff over the higher Qilian Mountain than the lower Heihe Vale.The lower precipitation efficiency make less precipitation amount over Heihe Vale and correspond with evaporation armunt so as to contribute quite smallness for runoff.In the atrmsphere column over the area of 2.5°×2.5°,the annual influent water vapor amount is 6678×108m3,the annual effluent water vapor amount is 6502×108m3,and the net water vapor amount is 176×108m3.Over theqlian-Heihe Valley,it is inevitable that the precipitation amount will be reduced because the influent water vapor is reducing along with air temperature rising year after year.
Definition and classification of non-structure measures for flood prevention
LIU Guo-wei
2003, 14(1): 98-103.
Abstract:
In view of the relationship between man and flood,the definition of non-structure measures for flood prevention is given as that,the non-structure measure for flood prevention is the measure which achieves the aim of flood prevention and flood disaster reduced by restriction of actions of man-self and improvement of the relationship between man and flood but not by structures.According to the definition,the non-structure measures for flood prevention is classified as four classifications, they are in view of flood physics properties,flood risk conception,management science,laws and regulations respectively,and the tactical thinking of each kind of non-structure measure for flood prevention is expounded as well.
Application of the Web GIS to the provincal flood control and command information service subsystem
ZHOU Hui-cheng, HE Bin, LIANG Guo-hua, XIAO Jian-min, YIN Jun-xian
2003, 14(1): 104-108.
Abstract:
With the rapid development of the Web and GIS technologies,it has been feasible and necessary to design a good sized flood control and command information service system.Nearly associated with the practice of the Heilongjiang Province flood control and command information service subsystem,the Web GIS's solution based on the ArcIMS is researched in this paper,and the several key techniques of applying the ArclMS are studied.The techniques are as follows:(1) Taking the obverse and the reversal information queries as examples,the data flow of the information query is researched and designed; (2) For the convenience of managing and using the spatial data,the method for dividing and organizing the map layers is studied;(3) For the economical and practical purpose of system,the switch between the different scale maps without sight equation is researched;and (4) According to the user's demand to display the map,how to write the map configuration file is discussed.The effect of these key techniques,which are applied to the practical design and development,is also illustrated.
Study on the region water resources carrying capacity
FENG Yao-long, HAN Wen-xiu, WANG Hong-jiang, LAN Ji-jian, HUANG Jin-ming
2003, 14(1): 109-113.
Abstract:
The concept of region water resources carrying capacity (RWRCC) is developed, the connotations and essence of RWRCC are revealed, RWRCC is considered as having the characteristic of "liquid", i.e., in a given status, RWRCC is fixed, but the representations of RWRCC can be various.The model for calculating RWRCC is established by taking the "carrying population" as its integration index and using the system optimizing method.The status quo of RWRCC in Tianjin area is calculated and analyzed approximately.
Application of GIS to the water dispatching decision support system
WANG Yu, WANG Dao-xi, WANG Jun-liang, WANG Tong, YANG Li-bin, HOU Chuan-he
2003, 14(1): 114-117.
Abstract:
The water dispatching below Sanmenxia resemvir is a non-structural and multiple-objective problem dealing with which deals with plenty of sectors and regions and is of storng spatially distribution information.With application of space analysis sub-system based on GIS,the space analysis and space description are realized,therefore the decision support functions are greatly enhanced.This paper presents the space data rmdel,the components,function and utilization of the space sup-system etc.
Review of studies on the water requirement for sediment transport of the lower Yellow River
SHI Wei, WANG Guang-qian
2003, 14(1): 118-123.
Abstract:
This paper reviews recent developments in study on water requirement for sediment transport in the Lower Yellow River,including the calculation method,the difference between flood season and dry season,the impact of reserwir operadon,and the required annual water consumption for sediment transport.Results of this study show that the required water consumption is not only related to the discharge and sediment concentration of the incoming flow,but also to the aggradation/degradation condition of the river bed.The water requirement differs during different periods in the year,that is,it is the smallest in the flood sewn,more in the non-flood season,and then the winter menths and the ice flood sewn in turn.Flow and sediment regulated by the reserwirs can effectively change the water requirement for sediment transport.It is suggested that the main method of high-efficiency,watersaving sediment transport in the lower Yellow River is the coordinatedoperation involving several reserwirs,with the Xiaolangdi Project releasing channel-forming discharge and high-concentration flow into its downstream sections,which can reduce sediment deposition in the Lower Yellow River reaches.This paper also lists a number of issues for further investigation.
Study on water right, available utilization and protection of water resources in international rivers
FENG Yan, HE Da-ming
2003, 14(1): 124-128.
Abstract:
Water resources in international rivers is one shared resources by several states,which is different from any other natural resources located in only one state.So it can be said that the ownership of water resources (for short "water right")of international rivers is alms shared by the riparian states.According to the characteristic of the shared water resources,the shared water right means that each riparian state has limited right on water uses,has the responsibility of protecting the shared water resources,has the right to trade the water right under Mme special conditions in order to realize the available uses of water resources,and so on.In order to realize the available utilization and the conservation of water right,some issues should be thought over:the water right owned by each riparian state should be keep the relatively stability,Mme agreements of water right distribution should be built armng riparian states,and the supervising mechanism of available use and exchange of water right also should be constituted,and so on.
2003, 14(1): 129-130.
Abstract: