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Experiments and sensitivity analyses for heat transfer in a meter-scale regularly fractured granite model with water flow

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Journal of Zhejiang university-Science A(Applied Physics & engineering) 2012年第12期13卷 958-968页

作者： Wei LU1,2.Yan-yong XIANG1 (1School of Civil engineering,Beijing Jiaotong university,Beijing 100044,{2.) (2.tate Key Laboratory of Simulation and Regulation of water Cycle in River Basin,{2. Institute of water resources and hydropower Research,Beijing 100038,{2.) 1. School of Civil engineering Beijing Jiaotong University Beijing 100044 China 2. State Key Laboratory of Simulation and Regulation of water Cycle in River Basin China Institute of Water Resources and Hydropower Research Beijing 100038 China

Experiments of saturated water flow and heat transfer were conducted for a meter-scale model of regularly fractured granite. The fractured rock model （height 1502.5 ram, width 904 mm, and thickness 300 mm）, embedded with two vertical and two horizontal fractures of pre-set apertures, was constructed using 18 pieces of intact granite. The granite was taken from a site currently being investigated for a high-level nuclear waste repository in china. The experiments involved different heat source temperatures and vertical water fluxes in the embedded fractures either open or filled with sand. A finite difference scheme and computer code for calculation of water flow and heat transfer in regularly fractured rocks was developed, verified against both the experimental data and calculations from the TOUGH2.code, and employed for parametric sensitivity analyses. The experiments revealed that, among other things, the temperature distribution was influenced by water flow in the fractures, especially the water flow in the vertical fracture adjacent to the heat source, and that the heat conduction between the neighboring rock blocks in the model with sand-filled fractures was enhanced by the sand, with larger range of influence of the heat source and longer time for approaching asymptotic steady-state than those of the model with open fractures. The temperatures from the experiments were in general slightly smaller than those from the numerical calculations, probably due to the fact that a certain amount of outward heat transfer at the model perimeter was unavoidable in the experiments. The parametric sensitivity analyses indicated that the tem- perature distribution was highly sensitive to water flow in the fractures, and the water temperature in the vertical fracture adjacent to the heat source was rather insensitive to water flow in other fractures.

关键词： Fractured granite water flow Heat transfer Physical modeling Numerical calculation Sensitivity analysis

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NUMERICAL SIMULATION OF HORIZONTAL BUOYANT WALL JET

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Journal of Hydrodynamics 2010年第1期22卷 58-65页

作者： HUAI Wen-xin LI Zhi-wei QIAN Zhong-dong ZENG Yu-hong HAN Jie PENG Wen-qi State Key Laboratory of water resources and {2. engineering Science Wuhan University Wuhan 430072 China Department of water Environment China Institute of Water Resources and Hydropower Research Beijing100038 China

This article applies the realizable k - ω model to simulate the buoyant wall jet and gives the results of cling length, centerline trajectory and temperature dilutions at certain sections. The comparison between the numerical results and Sharp＇s experimental data indicates that the model is effective in estimating velocity distribution and temperature dilutions. The velocity profiles at the cental plane and z-plane both show a strong similarity at certain distance from the nozzle, and the distributions of velocity and temperature dilutions also exhibit a similarity along the axial direction at centerline in the near-field. Based on the results, the article gives the corresponding relationships between the distance and the dilutions of velocity and temperature, which is useful in predicting the behavior of the wall buoyant jet.

关键词： buoyancy wall jet cling length velocity profile temperature dilution

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Approach to the Relation of Mutual-Feed Joint-Variation in Groundwater Management Model

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Journal of Earth Science 2012年第3期23卷 349-358页

作者：李平卢文喜靳孟贵杨青春 college of Chemistry and Materials South-Central University for Nationalities School of Environmental Studies China University of Geosciences college of Environment and resources Jilin University

In groundwater management,the exchanges between groundwater and other water such as surface water and spring water need to be *** exchange is dependent on the ground-water level,which is called *** pumping rate,groundwater level,and covariate interact and the relation of mutual-feed joint-variation is used to describe their *** article presents a new approach of dealing with the relation in groundwater management *** mathematical for-mulation of the relation,as an additional equality constraint in the optimization model,is developed using response matrix *** the groundwater management model with covariate is set *** code for the simulation and management of groundwater system with covariate is programmed with Fortran 90,and the optimal pumping rate,groundwater level,and covariate are *** approach is verified with a hypothetical ***,the approach is applied to the groundwater management of Qianguo（前郭） area in western Jilin（吉林） *** results indicate that the ap-proach is *** provides a universal solution for various covariates and reduces the computational complexity compared to iteration *** approach is proven to be very efficient to solve ground-water management problem with covariate.

关键词： covariate relation of mutual-feed joint-variation groundwater management response matrix

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STOCHASTIC ANALYSIS OF GROUNDwater FLOW SUBJECT TO RANDOM BOUNDARY CONDITIONS

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Journal of Hydrodynamics 2008年第5期20卷 553-560页

作者： SHI Liang-sheng YANG Jin-zhong CAI Shu-ying LIN Lin State Key Laboratory of water resources and {2. engineering Science Wuhan University Wuhan 430072 China

A stochastic model was developed to simulate the flow in heterogeneous media subject to random boundary conditions. Approximate partial differential equations were derived based on the Karhunen-Loeve （KL） expansion and perturbation expansion. The effect of random boundary conditions on the two-dimensional flow was examined. It is shown that the proposed stochastic model is efficient to include the random boundary conditions. The random boundaries lead to the increase of head variance and velocity variance. The influence of the random boundary conditions on head uncertainty is exerted over the whole simulated region, while the randomness of the boundary conditions leads to the increase of the velocity variance in the vicinity of boundaries.

关键词： groundwater flow Karhunen-Loeve (KL) expansion hydraulic head random boundary variance

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LARGE EDDY SIMULATION OF OPEN CHANNEL FLOWS WITH NONSUBMERGED VEGETATION

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Journal of Hydrodynamics 2011年第2期23卷 258-264页

作者： HUAI Wen-xin WU Zhen-lei QIAN Zhong-dong GENG Chuan State Key Laboratory of water resources and {2. engineering Science Wuhan University Wuhan 430072 China

Results of several Large Eddy Simulations （LES） this article. It is shown that the vegetation can make the flow of open channel flows with non-submerged vegetation are presented in structure in the mainstream direction uniform for both supercritical and subcritical flows. For subcritical flows, the LES results of the ensemble-average of time-averaged velocity distributions at four vertical sections around a single plant are in good agreement with measurements. The velocity sees double peaks at the upper and lower positions of flows. For supercritical flows, the ensemble-average velocities see some discrepancy between LES and measurement results. Some secondary flow eddies appear near the single plant, and they just locate in the positions of the double peaks in stream-wise velocity profiles. It is also found that the vegetation drag coefficient deceases as the Froude number increases.

关键词： non-submerged sub/supercritical flow peak value Large Eddy Simulation (LES) secondary flow drag coefficient

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A MATHEMATICAL MODEL OF MIGRATION AND EXPANSION OF MEANDER LOOPS

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Journal of Hydrodynamics 2010年第2期22卷 214-220页

作者： DAI Wen-hong TANG Hong-wu State Key Laboratory of Hydrology-water resources and Hydraulic {2. College of Water Conservancyand Hydropower Engineering Hohai University Nanjing 210098 China

This article presents a mathematical model of the plane evolution of alluvial meandering streams,through downstream migration and lateral expansion of meander *** the conditions prevailing in natural streams,the channel centerlines follow sine-generated curves,with an assumed steady-state turbulent and subcritical flow,of large width-to-depth ratio（≥ 15,for example） and small Froude number（Fr ）.The plane deformation of the channel is caused by the action on the banks of the convective vertically-averaged meandering *** growth（migration and expansion） of meander loops is attributed to the *** computational results of the model show that the obtained migration and expansion patterns of the meander loops are in good agreement with those of observations and measurements in similar meandering streams.

关键词： mathematical model downstream migration lateral expansion meander loop vertically-averaged flow bank deformation measurements

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GATE REGULATION SPEED AND TRANSITION PROCESS OF UNSTEADY FLOW IN CHANNEL

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Journal of Hydrodynamics 2008年第2期20卷 231-238页

作者： TAN Guang-ming DING Zhi-liang WANG Chang-de YAO Xiong State Key Laboratory of water resources and {2. engineering Science Wuhan University Wuhan 430072 China

The operation methods of channel and the speed of gate regulation have great influence on the transformation of flow in water conveyance channels. Based on characteristics method, a 1-D unsteady flow numerical model for gate regulation was established in this study. The process of water flow was simulated under different boundary conditions. The influence of gate regulation speed and channel operation methods on flow transition process was analyzed. The numerical results show that under the same conditions, with increasing regulation speed of the gate, the change rates of discharge and water level increase, while the response time of channel becomes shorter, and ultimately the discharge and water level will transit to the same equilibrium states. Moreover, the flow is easier to reach stable state, if the water level in front of the sluice is kept constant, instead of,behind the sluice. This study will be important to the scheme design of automatic operation control in water conveyance channels.

关键词： check gate regulation speed unsteady flow transition process numerical simulation

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A New Treatment of Depression for Drainage Network Extraction Based on DEM

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Journal of Mountain Science 2009年第4期6卷 311-319页

作者： WANG Yan PENG Hong CUI Peng ZHANG Wanshun QIAO Fei CHEN Cai'er School of Resource and Environmental Science Wuhan University Wuhan 430079 China college of water {2. and hydropower engineering Wuhan University Wuhan 430072 China Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China Chinese Academy of Environmental Sciences Beijing 100012 China

Depressions in landscapes function as buffers for water and sediment. A landscape with depressions has less runoff, less erosion and more sedimentation than that without depressions. Sinks in digital elevation models （DEMs） can be considered the real features that represent depressions in actual landscapes or spurious features that result from errors in DEM creation. In many hydrological and erosion models, all sinks are considered as spurious features and, as a result, these models do not deal with the sinks that represent real depressions. Consequently, the surface runoff and erosion are overestimated due to removing the depressions. Aiming at this problem, this paper presents a new method, which deal with the sinks that represent real depressions. The drainage network is extracted without changing the original DEM. The method includes four steps： detecting pits, detecting depressions, merging depressions, and extracting drainage network. Because the elevations of grid cells are not changed, the method can also avoid producing new fiat areas, which are always produced by the conventional filling methods. The proposed method was applied to the Xihanshui River basin, the upper reach of the Jialingjiang River basin, china, to automatically extract the drainage network based on DEM. The extracted drainage network agrees well with the reality and can be used for further hydrologic analysis and erosion estimation.

关键词： Drainage network extraction Depression processing Digital elevation model Wooden barrel effect Xihanshui River basin.

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Risk analysis model for landslide mass of high slope in dam area

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Science china(Technological Sciences) 2008年第S2期51卷 25-31页

作者： GU ChongShi1,2.HE XianFeng3,4,WU ZhongRu1,2.& SU HuaiZhi1,2.1 college of water Conservancy and {2. engineering,Hohai university,Nanjing 2.0098,china 2.National engineering Research Center of water resources Efficient Utilization and engineering Safety,Nanjing 2.0098,china 3 Yellow River Institute of Hydraulic Research,Zhengzhou 450003,china 4 Embankment Security Defect Prevention and Control engineering Research Center of MWR,Zhengzhou 450003,china 1. college of water Conservancy and {2. engineering Hohai University Nanjing 210098 China 2. National engineering Research Center of water {2. Efficient Utilization and engineering Safety Nanjing 210098 China 3. Yellow River Institute of Hydraulic Research Zhengzhou 450003 China 4. Embankment Security Defect Prevention and Control engineering Research Center of MWR Zhengzhou 450003 China

In order to identify the threat of reservoir bank landslide to dam safety and reduce the risk of dam failure,impact factors of the landslide are *** concept of landslide risk degree is put forward to measure the threat of landslide to dam *** monotony of the landslide risk assessment function which changes with different affecting factors is analyzed *** on gene automatic programming,a data mining model of the landslide risk assessment function is constructed combined with impact factors of reservoir bank landslide on dam *** the assessment function of landslide risk has been excavated and established according to practical project information,which provides a valuable reference for analyzing the impact of landslide on dam risk.

关键词： landslide dam failure risk landslide risk

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EXPERIMENTAL STUDY AND NUMERICAL SIMULATION OF FLUORIDE IN SAND

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Journal of Hydrodynamics 2006年第6期18卷 748-751页

作者： ZHANG Hong-mei SU Bao-yu School of resources and Safety engineering China University of Mining and Technology Beijing 100083China college Of water Conservancy and {2. engineering Hohai University Nanjing 210098China

The transport and transformation of fluoride in sand were studied by using soil tank test under the condition of saturated water in this article. Based on the analysis of the laboratory experiments, the rules of fluorine transportation and transformation were simulated in sand by solving the advection-diffusion equation. Through comparison between computed results and observed data , it is shown that the established model and determined parameters could be used to simulate the fluoride transport in sand.

关键词： sand fluoride dynamic test numerical simulation

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