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NUMERICAL MODELING OF COMPOUND CHANNEL FLOWS

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Journal of Hydrodynamics 2002年第4期14卷 106-109页

作者： Wang De-guan, Cheng Li college of water {2. and Environmental Engineering, hohai university, nanjing 2.0098, china college of water {2. and Environmental Engineering Hohai University Nanjing 210098 China

A numerical model capable of predicting flow characteristics in a compound channel was established with the 3-D steady continuity and momentum equations along with the transport equations for turbulence kinetic energy and dissipation rate. Closure was achieved with the aid of algebraic relations for turbulent shear stresses. The above equations were discretized with implicit difference approach and solved with a step method along the flow direction. The computational results showing the lateral distribution of vertical average velocities and the latio of total flow in the compound channel agree well with the available experimental data.

关键词： compound channel flow discharge ratio of channel and floodplain turbulence

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土石坝震害与抗震安全

水力发电学报 2011年第6期30卷 40-51页

作者：朱晟河海大学水文水资源与水利水电工程科学国家重点实验室南京210098 河海大学水电学院南京210098

结合世界上地震区已建土石坝的震害调查,对主要震害型式、产生机理以及防止震害的对策进行了剖析,分析了现代碾压式高土石坝抗震性能优良的内在原因。从设防标准、抗震能力与抗震风险以及坝体填筑设计质量控制指标等方面论证了现阶段强... 详细信息

结合世界上地震区已建土石坝的震害调查,对主要震害型式、产生机理以及防止震害的对策进行了剖析,分析了现代碾压式高土石坝抗震性能优良的内在原因。从设防标准、抗震能力与抗震风险以及坝体填筑设计质量控制指标等方面论证了现阶段强震区高土石坝建设需重视的问题。在深入开展土石坝抗震理论研究的基础上,适当提高坝料填筑设计指标以控制有害变形,强震区300m级高土石坝的建设是安全可行的。

关键词：地震土石坝液化滑坡永久变形

COUPLING EFFECT OF SEEPAGE FLOW AND RIVER FLOW ON THE BANK FAILURE

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Journal of Hydrodynamics 2011年第6期23卷 834-840页

作者： NING Bo WU- Shi-qiang TAN Ye-fei XIE Xing-hua YAN Jun YAN Zhong-min GENG Yan-qiong college of water Conservancy and {2. Engineering Hohai University Nanjing 210098 China nanjing Hydraulic Research Institute Nanjing 2100-29 China nanjing Hydraulic Research Institute.nanjing 2.002. China Lian Yungang Technical college Lian Yungang 222000 China

On the basis of the generalized physical model of the riverbank, the experiments were conducted to study the mechanisms of riverbank failure under the coupling effect of seepage flow and river flow. The experimental setup was specially designed, as well as test point location, parameters and procedures, and the main influencing factors were analyzed affecting riverbank failure based on the failure types, the variations of pore water pressure and soil displacement. The results indicated that the coupling effect has different influences on the bank failure in three aspects： the failure type, the process and the extent. In addition, the river flow played a more important role than the seepage flow in the coupling effect on the bank failure.

关键词： bank failure seepage flow river flow physical model test

A STUDY ON NUMERICAL METHOD OF NAVIER-STOKES EQUATION AND NON-LINEAR EVOLUTION OF THE COHERENT STRUCTURES IN A LAMINAR BOUNDARY LAYER

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Journal of Hydrodynamics 2006年第3期18卷 372-377页

作者： LU Chang-gen CAO Wei-dong QIAN Jian-hua State KeyLaboratory of Hydrology-water resources and Hydraulic Engineering and {2. of Environmental Science and Engineering Hohai University Nanjing 210098 China college of Environmental Science and Engineering Hohai University Nanjing 210098 China

A new method for direct numerical simulation of incompressible Navier-Stokes equations is studied in the paper. The compact finite difference and the non-linear terms upwind compact finite difference schemes on non-uniform meshes in x and y directions are developed respectively. With the Fourier spectral expansion in the spanwise direction, three-dimensional N-S equation are converted to a system of two-dimensional explicit-implicit The treatment of equations. The third-order mixed scheme is employed the three-dimensional for time integration. non-reflecting outflow boundary conditions is presented, which is important for the numerical simulations of the problem of transition in boundary layers, jets, and mixing layer. The numerical results indicate that high accuracy, stabilization and efficiency are achieved by the proposed numerical method. In addition, a theory model for the coherent structure in a laminar boundary layer is also proposed, based on which the numerical method is implemented to the non-linear evolution of coherent structure. It is found that the numerical results of the distribution of Reynolds stress, the formation of high shear layer, and the event of ejection and sweeping, match well with the observed characteristics of the coherent structures in a turbulence boundary layer.

关键词： non-uniform meshes compact finite differences scheme Fourier spectral expansion coherent structure boundary layer

A SIMPLIFIED NUMERICAL MODEL OF 3-D GROUNDwater AND SOLUTE TRANSPORT AT LARGE SCALE AREA

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Journal of Hydrodynamics 2010年第3期22卷 319-328页

作者： LIN Lin YANG Jin-Zhong ZHANG Bin ZHU Yan State Key Laboratory of water resources and {2. Engineering Wuhan University Wuhan 430072China Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 China

A simplified numerical model of groundwater and solute transport is developed. At large scale area there exists a big spatial scale difference between horizontal and vertical length scales. In the resultant model, the seepage region is particularly divided into several virtual layers along the z direction and vertical 1-D columns covering x-y 2.D area according to stratum properties. The numerical algorithm is replacing the full 3-D water and mass balance analysis as the 2.D Galerkin finite element method in x- and y-directions and 1-D finite differential approach in the z direction. The reasonable method of giving minimum thickness is successfully used to handle transient change of water table, drying cells and problem of rewetting. The solution of the simplified model is preconditioned conjugate gradient and ORTHOMIN method. The validity of the developed 3-D groundwater model is tested with the typical pumping and backwater scenarios. Results of water balance of the computed example reveal the model computation reliability. Based on a representative 3-D pollution case, the solute transport module is tested against computing results using the MT3DMS. The capability and high efficiency to predict non-stationary situations of free groundwater surface and solute plume in regional scale problem is quantitatively investigated. It is shown that the proposed model is computationally effective.

关键词： groundwater movement solute transport simplified model 3-D mass balance numerical simulation

Effect of granular size on the angle of repose in the chute

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Science china(Physics,Mechanics & Astronomy) 2009年第4期52卷 563-565页

作者： ZHOU Ying1 & ZHANG GuoQin2.1 college of Physics and Electronics Engineering,Taizhou university,Taizhou 318000,{2. 2.Zhejiang water Conservancy and hydropower college,Hangzhou 310018,{2. college of Physics and Electronics Engineering Taizhou University Taizhou 318000 China Zhejiang water Conservancy and hydropower {2. Hangzhou 310018 China

Avalanche in the chute has been studied to examine how the sizes of granules affect the angle of repose θr when the width of the chute is fixed. The results show that the angle of repose in the chute has exponential decay with λ,which is the reciprocal of granular diameter d. The fluctuation of the angle of repose is also studied during the chute being tilted,and the results indicate that the fluctuation of the angle of repose increases with the increase of granular diameter d.

关键词： Granular matter avalanche the angle of repose granular diameter

Research on the multi-level intake water temperature effect of the Yalong River Jinping-I hydropower project

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Science china(Technological Sciences) 2011年第S1期54卷 125-132页

作者： WU ShiYong 1,CAO Wei 1,WANG HongMei 1,SUN ShuangKe 2.&CHEN QiuWen 3 1 Ertan hydropower Development Company,Ltd.,Chengdu 610051,china 2.china Institute of water resources and hydropower Research,Beijing 100038,china 3 Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,china 1. Ertan hydropower Development Company Ltd. Chengdu 610051 China2. China Institute of Water Resources and Hydropower Research Beijing 100038 China3. Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

Based on the discussion of the multi-level intake application status of high dam reservoir,this paper takes the Jinping-I hydropower project reservoir in the Yalong River as an example,which is shaped by the highest 305 m high arch dam,and carries out the forecasting research on the reservoir temperature by numerical simulation and physical model *** paper studies the intake effect of withdrawing the surface warm water by the stoplog gates inlets and verifies the reliability of the mathematical model by comparative *** results show that for a high dam hydropower station,taking the appropriate multi-level intake measure can withdraw the surface warm water in the spawning season and provide a favorable environment for the fish *** technical ideas and implementation scheme are adopted in this *** can provide technical reference for the solutions of similar problems in the future and it also has important engineering significance on the research of water temperature in large deep reservoirs.

关键词： water temperature multi-level intake Jinping-I hydropower project

INTERACTIVE STUDY BETWEEN IDENTICAL COHERENT STRUCTURES IN THE WALL REGION OF A TURBULENT BOUNDARY LAYER

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Journal of Hydrodynamics 2002年第1期14卷 100-105页

作者： Lu Chang-gen (college of water {2. and Environment, hohai university, Nan jing 2.0098, china) college of water {2. and Environment Hohai University Nanjing 210098 China

A theoretical model for identica l coherent structures in the wall region of a turbulent boundary layer was propo sed, using the idea of general resonant triad of the hydrodynamic stability. The evolution of the structures in the wall region of a turbulent boundary layer wa s studied by combining the compact finite differences of high numerical accuracy and the Fourier spectral hybrid method for solving the three dimensional Navier -Stokes equations. In this method, the third order mixed explicit-implicit sch eme was applied for the time integration. The fifth-order upwind compact finite difference schemes for the nonlinear convection terms in the physical space, an d the sixth-order center compact schemes for the derivatives in spectral space were introduced, respectively. The fourth-order compact schemes satisfied by th e velocities and pressure in spectral space was derived. As an application, the method was implemented to the wall region of a turbulent boundary to study the e volution of identical coherent structures. It is found that the numerical result s are satisfactory.

关键词： coherent structure turbulent bounda ry layer compact finite difference

Coupling analysis of unsteady seepage and stress fields in discrete fractures network of rock mass in dam foundation

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Science china(Technological Sciences) 2011年第S1期54卷 133-139页

作者： CHAI JunRui 1,2.& XU WeiSheng 2.1 college of Hydraulic and Environmental Engineering,china Three Gorges {2.,Yichang 443002.china 2.college of hydropower Engineering,Xi’an {2. of Technology,Xi’an 710048,china 1. college of Hydraulic and Environmental Engineering China Three Gorges University Yichang 443002 China2. College of Hydropower Engineering Xi’an University of Technology Xi’an 710048 China

The drag force of water flow through single fracture and the coupling characteristics of seepage and stress in single fracture surface are analyzed,and a three dimensional model of coupled unsteady seepage and stress fields is *** model is used to the analysis of foundation rock mass of a high *** the coupling effects are considered,the changes of boundary heads have less influence on the inner head of rock mass,and the strong permeability of main fractures *** the coupling effects are not considered,the fractures distribution affects the inner head more *** the upstream water head declines,the inner head of dam foundation slightly declines and the hydraulic gradient distribution becomes smoother.A bigger upstream water level declining velocity has a stronger lag effect,meanwhile the values of stress components change more *** the upstream water level declining velocity directly affects the stability of rock mass in dam foundation and we should take into account the above factors to make sure the safety of the dam during reservoir level fluctuation period.

关键词： hydraulic engineering unsteady seepage stress coupling fractures network rock mass