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Journal of Hydrodynamics 2006年第5期18卷 593-596页

作者： RONG Yan-shu TU Qi-pu DUAN Li-yao College of Water Resources and Environment Hohai University Nanjing 210098 China Tianjin Institute of Meteorological Science Tianjin 300074 China Tianjin Institute of Meteorological Science Tianjin 300074 China nanjing university of Information Science and Technology Nanjing 210044 China Tianjin Climate Centre Tianjin 300074 China

Evaporation plays an important role in water balance on the land surface. In Northern china, the evaporation series of the recent 115 years was reconstructed on the basis of Yhornthwaite evaporation formula. The characteristics of the reconstructed series were analyzed using 10-year running mean filter, power spectrum method, and running t-text of abrupt changes on the paper. The results showed that there were remarkable interannual fluctuations with timescales of about quasi-8-year, 3-4-year, and quasi-2-year, and interdecadal oscillations with timescales of 57.5-year, quasi-23-year, and l l.5-year. Meanwhile, the abrupt changes of the evaporation series were also of interdecadal timescale. Either interannual fluctuations or interdecadal oscillations of evaporation were closely related to variations in air temperatures and precipitation.

关键词： reconstructed evaporation series interannual timescale interdecadal timescale Northern china

HYDRAULIC CHARACTERISTICS OF PARTIAL OPENING OF THE WORKING GATE FOR A DISCHARGE TUNNEL

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Journal of Hydrodynamics 2007年第4期19卷 488-493页

作者： WU Jian-hua FENG Shu-rong WU Wei-wei RUAN Shi-ping College of Water Conservancy and Hydropower Engineering Hohai University Nanjing 210098 China china Hydro Mid-South Design and Research Institute Changsha 410014 China

The partial opening of the working gate for a discharge tunnel is used more and more widely in the various conditions, such as releasing discharge to meet the needs of the various stages under construction, or of the operations at low reservoir levels. In this article the hydraulic characteristics were investigated of the partial opening of the working gate based on the physical model experiments of the discharge tunnel for the Longtan Hydropower Project, including the discharge coefficient, the surface profile of the free flow section, the bottom pressure distribution of the tunnel with an aerator, the cavity length just from the ramp, and the wall pressure of the curve section of the outlet. Some new issues were discussed and the properties were presented of the partial opening of the gate.

关键词： partial opening hydraulic characteristics working gate discharge tunnel

SIMULATION OF SOLUTE TRANSPORT IN A PARALLEL SINGLE FRACTURE WITH LBM/MMP MIXED METHOD

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Journal of Hydrodynamics 2008年第3期20卷 365-372页

作者： TAN Ye-fei ZHOU Zhi-fang College of Civil Engineering Hohai University NanJing 210098 China

This article deals with the solute transport in a single fracture with the combination of the Lattice Boltzmann Method （LBM） and Modified Moment Propagation （MMP） method, and this mixed method is proved to have several advantages over the LBM and Moment Propagation （MP） mixed method which leads to negative concentrations under some conditions in computation. The disadvantage of LBM/MP has been overcome to a certain extent. Also, this work presents an LBM solution of modeling single fractures with uniformly or randomly distributed grains, which can provide a new path of applying the LBM in solute transport simulation in fractures.

关键词： Lattice Boltzmann Method (LBM) Modified Moment Propagation (MMP) method LBM/MMP mixed method single fracture solute transport rough fracture

Approximate computation of Madaline sensitivity based on discrete stochastic technique

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Science china(Information Sciences) 2010年第12期53卷 2399-2414页

作者： ZHONG ShuiMing , ZENG XiaoQin, LIU HuiYi & XU Yan Institute of Pattern Recognition and Intelligent System, College of Computer and Information Engineering, hohai university, nanjing 210098, china Institute of Pattern Recognition and Intelligent System College of Computer and Information Engineering Hohai University Nanjing China

The computation of the sensitivity of a Madaline’s output to its parameter perturbation is system- atically discussed. Firstly, according to the discrete feature of Adalines, a method based on discrete stochastic technique is proposed, which derives some analytical formulas for the computation of Adalines’ sensitivity. The method can theoretically solve some problems that are unsolvable by the existing methods based on continu- ous stochastic techniques, release some unpractical constraints, and make it available to theoretically analyze the approximation error of Adalines’ sensitivity. Secondly, on the basis of the sensitivity of Adalines and the structural characteristics of Madalines, a new selection strategy depending on a type of dedication degree for computing Madalines’ sensitivity is proposed, which is superior to current popular way of simply averaging in both precision and complexity. The proposed formulas and algorithm have the advantages of simplicity, low computational complexity, small approximation error, and high generality, as have been verified by a great amount of experimental simulations.

关键词： Adaline Madaline feedforward networks sensitivity parameter perturbation stochastic discrete technique

Numerical simulation of two-phase turbulent flow in hydraulic and hydropower engineering

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Science china(Technological Sciences) 2007年第Z1期50卷 79-89页

作者： DAI HuiChao1,2?, WANG LingLing1, GAO JiZhang3, ZHANG XiaoDong3 & YANG ZhongHua2 1 College of Water Conservancy and Hydropower Engineering, hohai university, nanjing 210098, china 2 china Yangtze River Three Gorges Project Development Corporation, Yichang 443002, china 3 china Institute of Water Resources and Hydropower Research, Beijing 100044, china College of Water Conservancy and Hydropower Engineering Hohai University Nanjing China china Yangtze River Three Gorges Project Development Corporation Yichang China china Institute of Water Resources and Hydropower Research Beijing China

In connection with the specific features of high velocity aerated flow generated by hydraulic engineering structures, the mathematical model is developed for high turbulence air-water two-phase flow with the use of twin flow theoretical model in this paper. Furthermore the numerical method is proposed to treat bubbled flows. In addition, on the basis of air-water stratified twin flow model, the new calculation methods and free surface tracking technique are proposed to describe complicated movements of the free surface. Finally, the proposed model is used to calculate artificial aerated flows. The computed results coincide quite well with experimental results. This means that the proposed method can provide solid basis for practical engineering design.

关键词： high turbulence two-phase flow twin flow model aerated flow free surface

2-D CHARACTERISTICS LIKE MODEL AND OPEN BOUNDARY CONDITION FOR UNSTEADY OPEN CHANNEL FLOW MODELING

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Journal of Hydrodynamics 1999年第4期11卷 86-98页

作者： Wang De guan, He Jian jin hohai university, nanjing 210098, P.R.china

A characteristic like model is presented to calculate the two dimensional flow in open channels with finite or infinite dimensions. The comparisons between the computational results and experimental data show the model to be robust in simulating two dimensional unsteady flows. The comparisons also show the effectiveness of the open boundary condition in simulation of wave propagation process in an infinite domain with computational domain of finite dimension.

关键词： characteristic like model open boundary condition unsteady flow

Application analysis of empirical mode decomposition and phase space reconstruction in dam time-varying characteristic

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Science china(Technological Sciences) 2010年第6期53卷 1711-1716页

作者： ZHANG ZhiJun1,2,3,GU ChongShi1,2,BAO TengFei1,2,ZHANG Lan1,2 & YU Hong1,2 1 State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,hohai university,nanjing 210098,china 2 National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety,hohai university,nanjing 210098,china 3 Department of Civil,Environmental and Geomatic Engineering,Swiss Federal Institute of Technology,Zurich 8093,Switzerland State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Nanjing China National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety Hohai University Nanjing China Department of Civil Environmental and Geomatic Engineering Swiss Federal Institute of Technology Zurich Switzerland

In view of some courses of the time-varying characteristics processing in the analysis of dam deformation,the paper proposes a new method to analyze the dam time-varying characteristic based on the empirical mode decomposition and phase space reconstruction *** of all,to reduce the influences on the traditional statistical model from human factors and assure the analysis accuracy,response variables of the time-varying characteristic are obtained by the way of the empirical mode decomposition;and then,a phase plane of those variables is reconstructed to investigate their processing *** methods have already been applied to an actual project and the results showed that data interpretation with the assists of empirical mode decomposition and phase space reconstruction is effective in analyzing the perturbations of response variables,explicit in reflecting the entire development process,and valid for obtaining the evolution rules of the time-varying *** methodology is a powerful technical support for people to further master the rules of dam operation.

关键词： dam safety monitoring dam time-varying characteristic empirical mode decomposition phase space reconstruction

SIMULATION OF THERMAL TRANSPORT IN AQUIFER:A GWHP SYSTEM IN CHENGDU,china

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Journal of Hydrodynamics 2009年第5期21卷 647-657页

作者： ZHOU Yan-zhang ZHOU Zhi-fang Institute of Groundwater Science and Engineering Hohai University Nanjing 210098 China

With an established convection-dispersion model for the thermal transport in aquifer, the thermal transport processes in an unconfined aquifer of a Groundwater Heat Pump （GWHP） system in Chengdu, china, are simulated with double-well intervals and cooling-load design fluctuations in summer running period under special groundwater flow and heat source conditions, and the stage-characteristics of the thermal transport in the aquifer are investigated in the running cycle （1 year） numerically. The results show that the thermal transport in the aquifer is closely related to the distance between pumping and injecting wells and the cooling-load design fluctuations, especially, to the cycling water volume. The thermal transport in the aquifer sees different characteristics in the two states in the pumping-recharging stages in summer/winter and the storing stages in spring/autumn. With the hydro-geologic theory and the numerical model, the effect of the groundwater-flow on the thermal transport in the unconfined aquifer is discussed.

关键词： Groundwater Heat Pump (GWHP) thermal transport in aquifer numerical simulation groundwater flow

A FIELD TEST DATA RESEARCH BASED ON A NEW HYDRAULIC PARAMETERS QUICK TEST TECHNOLOGY

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Journal of Hydrodynamics 2010年第4期22卷 562-571页

作者： ZHAO Yan-rong ZHOU Zhi-fang School of Earth Sciences and Engineering Hohai University Nanjing 210098 China

The hydraulic parameter quick test system in accordance with the oscillation principle can overcome the shortcomings of traditional methods in determining hydraulic parameters which,besides having complex hydrogeological restrictions and needing complex equipment in the field,are often both time and energy consuming,and high *** on the hydrogeological conditions in the north anchorage of Taizhou Yangtze River Highway Bridge,a quick hierarchical test is carried out for different depths of single-hole drilling to verify the function of the system in this ***,with a purification of the raw data gathered in the test by wavelet denoising,the hydraulic parameters are worked out by adopting the Kipp model.A comparison between the Kipp model results and stratigraphic data as well as pumping test results justifies the reliability and accuracy of the new *** study finds other advantages of the method like high efficiency in operation,flexibility in stratified test,as well as ***,the technology is of significant practical value and application prospect.

关键词： hydraulic parameters oscillation principle slug test field test wavelet denoising

AN APPROACH TO SEPARATING THE CURRENT VELOCITY IN ESTUARINE AND COASTAL WATERS

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Journal of Hydrodynamics 2009年第4期21卷 512-519页

作者： NI Zhi-hui SONG Zhi-yao WU Li-chun State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Ocean College Hohai University Nanj ing 210098 China Key Laboratory of Virtual Geographic Environment Ministry of Education Nanjing Normal University Nanjing 210097 China Chongqing Education College Chongqing 400067 China

In the near-shore waters, the actual flow is mainly induced by tide, wind and salinity, and the river water runoff should also be included as a component in the estuary waters. The interactions among these major components are very complicated. Many approaches were proposed to study isolated tide and wind-driven currents or run-off based on the measured velocity, with all its components taken as a whole. In this article, firstly, based on the actual hydrodynamic characteristics of estuarine and coastal waters, an approach is proposed to separate the measured velocity by considering the theoretical current velocity profiles and using the least squares method. The vertical structures of tidal, wind-driven currents, density current and runoff can be obtained as well as their proportions in the measured velocity. Then, this approach is applied to the analysis of velocity data obtained in the North Branch of Yangtze River estuary and of laboratory test data. The results are found to be satisfactory. Finally, this approach is used to separate the measured velocity in the South Branch of Yangtze River estuary, to determine not only the bed friction velocity and roughness height, but also the surface wind stress, and to estimate the wind velocity data above the water surface. The results show that this method is simple in principle, practical in use, and reasonable in obtained results. So it can be used to effectively analyze the field data.

关键词： tide wind-driven current density current river water runoff friction velocity roughness height velocity separation