检索结果-南通市图书馆

hydraulic characteristics OF PARTIAL OPENING OF THE WORKING GATE FOR A DISCHARGE TUNNEL

在线全文

学校读者我要写书评

暂无评论

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

EXPERIMENT OF IMPACT OF RIVER hydraulic characteristics ON NUTRIENTS PURIFICATION COEFFICIENT

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2007年第3期19卷 387-393页

作者： WANG Pei-fang WANG Xiao-rong WANG Chao State Key Laboratory of Pollution Control and Resource Reuse School of Environment Nanjing University Nanjing 210093 China State Key Laboratory of Hydrology-Water Resources and hydraulic Engineering Hohai University Nanjing 210098 China Key Laboratory of Intergrated Regulation and Resource Development on Shallow Lakes College of Environmental Science and Engineering Hohai University Nanjing 210098 China

hydraulic characteristics of a river are the key factors for river water quality improvement and river restoration. A simulated river was exploited to study the interactions between water contaminant purification coefficients and the characteristics of the river, such as the cross-section velocity, water depth, Reynolds number, and Froude number. To enhance the purification capacity of the river, detritus with 5 mm to 10 mm in diameter and contact surface area per volume of 87.6 m^2/m^3 were constructed naturally at the bed and along one side of the bank to form half shape of the river cross-section. During the one-month experiment （including 3 periods） from the third of November to the fourth of December, 2005, three categories of hydraulic conditions were investigated. Results show that the purification coefficient （K） of Total Nitrogen （TN） is closely coherent with the hydraulic retention time （T）, river length （L）, Reynolds number （Re） and Froude number （Fr）. The relationship of K and T generally agrees with the power law under the three experimental water hydraulic conditions. Based on these results, the optimal Re and Fr ranges can be obtain to serve as a guideline for ecological re-engineering design to improve river water quality and restore river ecosystem.

关键词： hydraulic characteristics total nitrogen,purification coefficient interaction simulated river

The hydraulic characteristics of end-dump closure with the assistance of backwater-sill in diversion channel

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2016年第5期28卷 886-896页

作者：陆贺胡志根刘全吕国轩叶建群任金明 The State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan 430072 China Huadong Engineering Corporation Limited of Powerchina Hangzhou 310014 China

The river closure is a key step in the water dam construction, and the end-dump closure is a general way to cut offthe river flow. The hydraulic characteristics at the closure gap are the main factors which affect the extent of closure difficulty. A method is proposed to reduce the difficulty of diversion channel closure by pre-building a closure structure called the backwater-sill at the downstream toe of the closure gap to change the flow pattern at the closure gap. The results of the physical model test and the three- dimensional numerical simulation indicate that the backwater-sill has the effects of raising the water level at the downstream toe of the closure gap, decreasing the water surface gradient, and reducing the closure drop and the flow velocity at the closure gap. The schemes with different dike widths, different closure gap widths, and different backwater-sill widths and heights are simulated. The results show that the height of the backwater-sill is the key factor affecting the hydro-indicators at the closure gap, while the influe- nce of the dike width, the closure gap width or the backwater-sill width can be ignored. The higher the backwater-sill is, the lower the hydro-indicators will be. Based on the numerical simulations and the physical model tests on the hydraulic characteristics at the closure gap of the backwater-sill assisted closure, the hydro-indicators and its calculation method are proposed to provide a theoreti- cal support for the river closure.

关键词： diversion channel closure closure structure end-dump closure backwater-sill hydraulic characteristics

EXPERIMENTAL FEEDBACK ON THE INVESTIGATION OF hydraulic characteristics FOR THE SHIP-LOCK FILLING AND EMPTYING SYSTEM OF TGP

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2005年第6期17卷 770-775页

作者： NIU Xin-qiang JIANG Xiao-min School of Hydropower and information Engineering Huazhong University of Science and TechnologyWuhan 430074 China Changjiang Institute of Survey Planning Design and Research CWRC Wuhan 430010 China

Where hydraulic characteristics of ship lock filling and emptying system are concerned, there are much bigger differences between prototype and model experiments. Based on the results of the prototype experiments fur the Three Gorges Project （TGP）, experiments on the feedback model were conducted of the ship-lock filling and emptying system, by means of technologies of drag reduction, under similar conditions as the operation of the prototype project. The experimental results show that the difference of drag co efficient reached-44% hetween the prototype and the model for the filling and emptying system of the ship-lock No. 3 for TGP and the difference of discharge coefficient was ahout 33% between them. The technologies of drag reduction are more efficient in the simulation of a ship lock filling and emptying system in order to he consistent for discharge, water level, time average pressure and pulsating pressure between prototypes and models.

关键词： hydraulic characteristics filling and emptying system ship-lock feedback experiment

Experimental study on the hydraulic characteristics of vortex diodes

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2011年第2期54卷 332-337页

作者： JIAO Lei CHEN CongNan LIU JinTao YIN JunLian WANG LeQin Institute of Chemical Machinery Department of Chemical and Biological Engineering Zhejiang University Hangzhou 310027 China

Vortex diode,as an important component in power fluidics,has been used in nuclear reprocessing engineering where it is desirable to avoid pumps with moving *** performance of the fluidic system depends on the matched design parameters of vortex diodes and the supporting ***,no clear guidelines for design and optimization of vortex diodes system are ***,we carried out detailed experimental study on hydraulic characteristics of the vortex diodes system with changeable parameters to evolve such *** study covered a wide range of a vortex diode and vortex diodes *** variation of averaged discharge and volumetric efficiency in respect to air supply pressure,liquid level of water tank and liquid level stroke of gas-liquid energy converter was *** experimental results were analyzed to develop design *** guidelines are shown to be useful for obtaining the design parameters that would yield the desired hydrau- lic performance for the required operating conditions.

关键词： vortex diode hydraulic characteristics design parameter volumetric efficiency averaged discharge

NUMERICAL SIMULATIONS OF THE hydraulic characteristics OF SIDE INLET/OUTLETS

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2011年第1期23卷 48-54页

作者： YE Fei GAO Xue-ping North China University of Water Conservancy and Electric Power Zhengzhou 450011 China School of Civil Engineering Tianjin University Tianjin 300072 China

The hydraulic characteristics at the side inlet/outlet of pumped storage plants is studied by numerical simulations,covering the flow distribution,head loss,vortex,and *** on the physical model test,the realizable k-εturbulence model is used in the 3-D simulation of the side inlet/outlet.A new scheme is suggested to obtain the uneven flow distribution over three branch *** variation of the free surface with the reservoir water level under the pumped condition is simulated,with results consistent with the experimental results.

关键词： hydraulic characteristics side inlet/outlet pumped storage plant numerical simulation realizable k-εturbulence model

Theoretical and numerical study of hydraulic characteristics of orifice energy dissipator

在线全文

学校读者我要写书评

暂无评论

Water Science and Engineering 2010年第2期3卷 190-199页

作者： Ning HE Zhen-xing ZHAO Institute of High Energy Physics CAS Beijing 100049 R R. China College of Mechanics and Materials Hohai University Nanjing 210098 P. R. China

Different factors affecting the efficiency of the orifice energy dissipator were investigated based on a series of theoretical analyses and numerical simulations. The main factors investigated by dimension analysis were identified, including the Reynolds number （Re）, the ratio of the orifice diameter to the inner diameter of the pipe （ did ）, and the ratio of distances between orifices to the inner diameter of the pipe （ LID ）. Then, numerical simulations were conducted with a k-ε two-equation turbulence model. The calculation results show the following： hydraulic characteristics change dramatically as flow passes through the orifice, with abruptly increasing velocity and turbulent energy, and decreasing pressure. The turbulent energy appears to be low in the middle and high near the pipe wall. For the energy dissipation setup with only one orifice, when Re is smaller than 105, the orifice energy dissipation coefficient K increases rapidly with the increase of Re. When Re is larger than l05, K gradually stabilizes. As diD increases, K and the length of the recirculation region L1 show similar variation patterns, which inversely vary with diD. The function curves can be approximated as straight lines. For the energy dissipation model with two orifices, because of different incoming flows at different orifices, the energy dissipation coefficient of the second orifice （K2） is smaller than that of the first. If LID is less than 5, the K value of the LID model, depending on the variation of/（2, increases with the spacing between two orifices L, and an orifice cannot fulfill its energy dissipation function. If LID is greater than 5, K2 tends to be steady; thus, the K value of the LID model gradually stabilizes. Then, the flow fully develops, and L has almost no impact on the value of K.

关键词： orifice energy dissipator theoretical analysis numerical simulation k-ε two-equation turbulent model hydraulic characteristics

hydraulic characteristics of Low Crested Structures under Wave Attack

在线全文

学校读者我要写书评

暂无评论

Journal of Shipping and Ocean Engineering 2011年第3期1卷 141-149页

作者： I.G.B. Siladharma D.M. Sulaiman Department of Civil Engineering Udayana University Bali 80232 Indonesia Experimental Station for Coastal Engineering of Research Center for Water Resources Bali 80237 Indonesia

Two-dimensional physical models of low crested breakwaters were tested to establish the effect of water depth, crest width, slope, stone size, core permeability and incident wave characteristics on the wave transformation processes. The structure of the breakwaters can be used as coastal protection system by reducing the amount of incoming wave energy. Effect of slope, core permeability, water depth and incident wave characteristics on the stability was also studied. The breakwater model consisted of a core and two armour layers attacked by irregular waves. This paper discusses and compares the test results with the existing design equations. In general, the existing design equations do not seem to predict the wave transmission and reflection accurately for the range of test data. In the range of variable tested, it was observed that the water depth, crest width and wave period have a significant influence on wave transmission process. Further, results show strong influence of the water depth and wave period on the wave reflection process. The structural stability of low crested breakwaters is very much affected by the water depth and wave period.

关键词： Low crested structures wave transmission and reflection hydraulic characteristics structure stability.

Numerical Study on hydraulic characteristics and Discharge Capacity of Modified Piano Key Weir with Various Inlet/Outlet Width Ratio

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Engineering and Technology 2023年第1期11卷 113-135页

作者： Ilan Ich Genguang Zhang Anbin Li Vinhteang Kaing Ty Sok College of Water Resources and Architectural Engineering Northwest A&F University Yangling China Faculty of Hydrology and Water Resources Engineering Institute of Technology of Cambodia Russian Federation Blvd. Phnom Penh Cambodia Department of Civil and Environmental Engineering School of Environment and Society Tokyo Institute of Technology Tokyo Japan Research and Innovation Center Institute of Technology of Cambodia Russian Federation Blvd. Phnom Penh Cambodia

A modified piano key weir with a rounded nose and a parapet wall (MPKW) can improve the discharge capacity significantly compared to a standard piano key weir. However, the optimum of the inlet/outlet width ratio (Wi/Wo) on the discharge efficiency of MPKW is still not investigated numerically. The present work utilized the numerical modeling to investigate and analyze the effects of the inlet/outlet key width ratios on the hydraulic characteristics and discharge capacity of the MPKW. To validate the numerical model with the experimental data, the results indicate that the average relative error is 2.96%, which confirms that the numerical model is fairly well to predictthe specifications of flow over on the MPKW. Numerical simulation results indicated that the discharge capacity of the MPKW can be improved up to 8.5% by optimizing the Wi/Wo ratio ranging from 1.53 to 1.67 even if the other parameters of the MPKW keep unchanged. A big Wi/Wo ratio generally leads to an increase in discharge capacity at low heads and a little effect on the discharge efficiency at high heads. The discharge efficiency of the inlet and outlet crests increases up to 9.6% for high heads, while discharge efficiency of the lateral crest decreases up to 23.5% compared with the reference model. The findings of the study revealed that the intrinsic influencing mechanism of the Wi/Wo ratio on the discharge performance of MPKWs.

关键词： Discharge Capacity FLOW-3D hydraulic characteristics Numerical Simulation Modified Piano Key Weir Parameter Optimization