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Experiments on Development of Channel Pattern in the Process of River Reformation

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四川大学学报（工程科学版） 2005年第S1期37卷 128-132页

作者： ZHANG Junyong CHEN Li LIU Yucheng DING Zhiliang(state key Lab.of {2. resources and hydropower Eng.Sci.,wuhan Univ.,wuhan 4.0072,china) Lab. of water resources and {2. Eng. Sci. Wuhan Univ. Wuhan 430072 China

The changing of flow conditions caused by construction of hydro-projects will result in river's refor- mation and development of channel *** this paper,the development of channel pattern in the process of reformation is studied by means of flume *** of slope,grain size,angle-of-inflow,dis- charge and discharge process are comprehensively analyzed according to the experimental *** was found that the channel would be widened as the river slope or discharge increased and grain s...

关键词： reformation process channel pattern angle-of-inflow discharge process

C-S-H Cluster Microstructure and Bonding Force Investigation base on AFM Technology

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Journal of wuhan university of Technology(Materials Science) 2010年第4期25卷 592-595页

作者：张博何真 state key {2. of water resources and hydropower engineering Science Wuhan University

AFM （atomic force microscopy） technology was applied on C-S-H （calcium silicate hydrate phase） microstructure investigation. The topographies of hydrated C3S （Tricalcium silicate） samples were firstly acquired with AFM. Accordingly, C-S-H can be identified according its pattern. Then the hydrated pssortland cement samples at different curing time were scanned with AFM. The topographies and force displacement curve were acquired and its characters at different days were summarized and analyzed. These results are very meaningful for C-S-H microstructure further investigation and cement-base material macro scale properties improvement.

关键词： C-S-H atomic force microscopy microstructure tricalcium silicate

Experimental Study on the Distribution of Soil Nitrate and Ammonium Nitrogen under Controlled Drainage

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wuhan university Journal of Natural {2. 2009年第6期14卷 532-536页

作者： YANG Lin, HUANG Jiesheng, ZHAO Lirong, HUANG Zhiqiang state key {2. of water resources and hydropower engineering Science, wuhan university, wuhan 4.0072, Hubei, china state key {2. of water resources and hydropower engineering Science Wuhan University Wuhan 430072 Hubei China

A field experimental project was set up to assess the effects of controlled drainage on the distribution and concentration of nitrogen in the soil at the Irrigation and Drainage Experimental Station under Four-Lake engineering Administration of Jingzhou City, Hubei Province. Two plots drain runoff by controlled drainage system, with an area of 0.1 hm^2.（2. m×50 m） each. The third one with an area of 0.04 hm^2.（8 m×50 m） has a conventional subsurface drainage system. Under this experimental condition, the study draws the following conclusions： ① The controlled drainage system has a remarkable effect on the diminishing ratios of nitrate nitrogen between neighboring layers. It is presented that the diminishing ratio increases with the raising height of drain outlet. Controlled drainage system also reduces the transference of nitrate nitrogen in topsoil.② Different from nitrate nitrogen, the concentration of ammonium nitrogen is stable along the longitudinal section of soil, which is little affected by the controlled drainage system. It indicates that the concentration of ammonium nitrogen decreases according to the lowering of controlling height of the drain outlet.

关键词： controlled drainage nitrate nitrogen ammonium nitrogen controlling height of drain outlet

SIMULATIONS OF THE THREE-DIMENSIONAL TOTAL DISSOLVED GAS SATURATION DOWNSTREAM OF SPILLWAYS UNDER UNSTEADY CONDITIONS

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Journal of Hydrodynamics 2010年第4期22卷 598-604页

作者： FU Xiao-li LI Dan ZHANG Xiao-feng state key {2. of water resources and hydropower engineering Science Wuhan University Wuhan 430072 China

Dams are often operated in a way to discharge over the spillways,which would cause a high dissolved concentration of air and be harmful to *** bubble transfer and the water surface transfer play an important role in affecting the concentration of the Total Dissolved Gas（TDG）.Based on recent numerical simulations of the total dissolved gas saturation,in this article,a two-phase TDG transport equation is adopted to develop an unsteady three-dimensional（3-D） two-phase flow Computational Fluid Dynamics（CFD） model,including a number of parameters such as water depth,pressure and air volume *** model is used to predict the hydrodynamics and the TDG distribution under unsteady discharge *** agreement between measured and numerical results is obtained for a case study.

关键词： gas supersaturation anisotropic two-phase flow

UNIFIED MODEL FOR SPLASH DROPLETS AND SUSPENDED MIST OF ATOMIZED FLOW

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Journal of Hydrodynamics 2008年第1期20卷 125-130页

作者： LIU Shi-he SUN Xiao-fei LUO Jing state key {2. of water resources and hydropower engineering Science Wuhan University Wuhan 430072 China

In this article, the unified mathematical model for splash droplets and suspended mist of atomized flow was established, which classifies the atomized sources into the splash source and the suspended source. For the splash source, the Lagrangian method was used to simulate the random motion of splash water droplets, and for the suspended source the theory of air-water two-phase flow was used to simulate the mist flow moving in particle clouds. The rainfall intensity of the atomized flow was obtained by summarizing the rainfall intensities relative to the above two types of atomized sources. Both experimental data and prototype observation data were used for the verification of the mathematical model. For both the distribution of rainfall intensity, and the outer edge of the atomized flow, the simulation results are in agreement with the experimental data or prototype observation data.

关键词： two phase flow atomized flow splash water drop suspended mist

Global analysis on slope stability and its engineering application

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Science china(Technological sciences) 2009年第2期52卷 507-512页

作者： ZHENG Hong1,2.& ZHOU ChuangBing3 1 state key {2. of Geomechanics and Geotechnical engineering, wuhan 430071, china 2.5} Three Gorges university, key {2. of Geological Hazards on Three Gorges Reservoir Area, Ministry of Education, Yi Chang 443002. china 3 School of Civil engineering,{12., wuhan 4.0072, china 1. state key {2. of Geomechanics and Geotechnical engineering Wuhan 430071 China 2. china Three Gorges university Key Laboratory of Geological Hazards on Three Gorges Reservoir Area Ministry of Education Yi Chang 443002 China 3. School of Civil engineering Wuhan University Wuhan 430072 China

In hydraulic engineering, sometimes it is necessary to consider the stability of sliding bodies with lateral frictional boundaries. Neither the existing three dimensional limit equilibrium methods nor the commercial software products are able to treat such situations. The three dimensional factor of safety is accordingly underestimated; while the shearing strength based on the three dimensional back analysis is overestimated. In this study, the lateral boundaries are regarded as the part of the slip surface. Based on the expression of the normal pressure on the slip surface and the patch interpolation, a rigorous solution for the three dimensional limit equilibrium analysis is realized. Meanwhile, the proposed procedure is applied to the stability analysis of the slope with a cable platform on the right bank in Da Gang Shan hydraulic project under construction.

关键词： slope stability the limit equilibrium methods three dimensional problems

Multi-resolution representation of digital terrain models with terrain features preservation

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Science china(Technological sciences) 2008年第S1期51卷 145-154页

作者： LI QingQuan1,WANG Zhi1,2.& YANG BiSheng1 1 state key {2. of Information engineering in Surveying,Mapping and Remote Sensing,wuhan university,wuhan 430079,china 2.School of Remote Sensing and Information engineering,wuhan university,wuhan 430079,china 1. state key {2. of Information engineering in Surveying Mapping and Remote Sensing Wuhan University Wuhan 430079 China2. School of Remote Sensing and Information Engineering Wuhan University Wuhan 430079 China

multi-resolution TIN model is an important issue in the contexts of visu-alization,virtual reality (VR),and geographic information systems (GIS). This paper proposes a new method for constructing multi-resolution TIN models with multi-scale topographic features preservation. The proposed method is driven by a half-edge collapse operation in a greedy framework and employs a new quadric error metric to efficiently measure geometric errors. We define topographic features in a multi-scale manner using a center-surround operator on Gaussian-weighted mean curvatures. Experimental results demonstrate that the proposed method performs better than previous methods in terms of topographic features preservation,and is able to achieve multi-resolution TIN models with a higher accuracy.

关键词： digital terrain models level of detail differential-geometry quadric error metrics topographic feature

LARGE EDDY SIMULATION OF THE INTERACTION BETWEEN WALL JET AND OFFSET JET

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Journal of Hydrodynamics 2011年第5期23卷 544-553页

作者： LI Zhi-wei HUAI Wen-xin HAN Jie state key {2. of water resources and hydropower engineering Science Wuhan University Wuhan 430072 China

The interaction between a plane wall jet and a parallel offset jet is studied through the Large Eddy Simulation （LES）. In order to compare with the related experimental data, the offset ratio is set to be 1.0 and the Reynolds number Re is 1.0× 104 with respect to the jet height L and the exit velocity U0. The Finite Volume Method （FVM） with orthogonal-mesh （6.17× 106 nodes） is used to discretize governing equations. The large eddies are obtained directly, while the small eddies are simulated by using the Dynamic Smagorinsky-Lily Model （DSLM） and the Dynamic Kinetic energy Subgrid-scale Model （DKSM）. Comparisons between computational results and experimental data show that the DKSM is especially effective in predicting the mean stream-wise velocity, the half-width of the velocity and the decay of the maximum velocity. The variations of the mean stream-wise velocity and the turbulent intensity at several positions are also obtained, and their distributions agree well with the measurements. The further analysis of dilute characteristics focuses on the tracer concentration, such as the distributions of the concentration （i.e., C / C0 or C / C,,）, the boundary layer thickness 6c and the half-width of the concentration b., the decay of the maximum concentration （ C / Co） along the downstream direction. The turbulence mechanism is also analyzed in some aspects, such as the coherent structure, the correlation function and the Probability Density Function （PDF） of the fluctuating velocity. The results show that the interaction between the two jets is strong near the jet exit and they are fully merged after a certain distance.

关键词： wall jet offset jet dilute characteristic coherent structure

Semi-Supervised Classification based on Gaussian Mixture Model for remote imagery

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Science china(Technological sciences) 2010年第S1期53卷 85-90页

作者： XIONG Biao1,ZHANG XiaoJun1 & JIANG WanShou1,2.1 state key {2. of Information engineering in Surveying,Mapping and Remote Sensing,wuhan university,wuhan 430079,china 2.state key {2. of Remote Sensing Science,Beijing,china 1. state key {2. of Information engineering in Surveying Mapping and Remote Sensing Wuhan University Wuhan 430079 China2. State Key Laboratory of Remote Sensing Science Beijing China

Semi-Supervised Classification (SSC),which makes use of both labeled and unlabeled data to determine classification borders in feature space,has great advantages in extracting classification information from mass *** this paper,a novel SSC method based on Gaussian Mixture Model (GMM) is proposed,in which each class’s feature space is described by one *** show the proposed method can achieve high classification accuracy with small amount of labeled ***,for the same accuracy,supervised classification methods such as Support Vector Machine,Object Oriented Classification,*** be provided with much more labeled data.

关键词： remote sensing image classification Semi-Supervised Classification Gaussian Mixture Model EM algorithms