检索结果-南通市图书馆

flume experiment Investigation on Propagation Characteristics of Tidal Bore in A Curved Channel

China Ocean Engineering 2023年第1期37卷 131-144页

作者： FAN Jun TAO Ai-feng SHI Mo-quan LI Ying PENG Ji Key Laboratory of Ministry of Education for Coastal Disaster and Protection Hohai UniversityNanjing 210098China College of Harbour Coastal and Offshore EngineeringHohai UniversityNanjing 210098China The Adminstrative Committee of Nantong Haimen Sanchang Industrial Park Nantong 226121China Zhejiang University of Water Resources and Electric Power Hangzhou 310018China China Renewable Energy Engineering Institute Beijing 100120China

Tidal bore is a special and intensive form of flow movement induced by tidal effect in estuary areas, which has complex characteristics of profile, propagation and flow velocity. Although it has been widely studied for the generation mechanism, propagation features and influencing factors, the curved channel will complicate the characteristics of tidal bore propagation, which need further investigation compared with straight channel. In this study, the flume experiments for both undular and breaking bores’ propagation in curved channel are performed to measure the freesurface elevation and flow velocity by ultrasonic sensors and ADV respectively. The propagation characteristics,including tidal bore height, cross-section surface gradient, tidal bore propagation celerity, and flow velocity are obtained for both sides of the curved channel. And three bore intensities are set for each type of tidal bores. The freesurface gradients are consistently enlarged in high-curvature section for undular and breaking bores, but have distinct behaviors in low-curvature section. The spatial distributions of tidal bore propagation celerity and flow velocity are compared between concave and convex banks. This work will provide experimental reference for engineering design of beach and seawall protection, erosion reduction and siltation promotion in estuary areas with the existence of tidal bores.

关键词： tidal bore curved channel flume experiment propagation celerity bore intensity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

flume experiment on Stream Blockage by the Debris Flow From Tributary

引用

四川大学学报（工程科学版） 2005年第S1期37卷 64-70页

作者： He, Yiping Guo, Zhixue Li, Yong Cui, Peng Wang, Zhaoyin Dept. of Hydraulic and Hydro-electrical Eng. Tsinghua Univ. Beijing 100084 China Chengdu Inst. of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China State Key Lab. of Hydraulics and Mountain River Eng. Sichuan Univ. Chengdu 610065 China

Stream blockage by the debris flow from tributary valleys is a common phenomenon in mountainous area,which takes place when large quantities of sediment transported by debris flow reaches a river channel causing its complete or partial blockage.The dam formed by debris flow may causes upstream and downstream flooding,and presents great threat to people and property.Because of the catastrophic influence on people and property,debris-flow dam has attracted many attentions from the researchers and local adm...

关键词： Debris flow blockage critical condition flume experiment

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A STUDY OF DRAG COEFFICIENT RELATED WITH VEGETATION BASED ON THE flume experiment

引用

Journal of Hydrodynamics 2010年第3期22卷 329-337页

作者： HUI Er-qing HU Xing-e JIANG Chun-bo MA Fang-kai ZHU Zhen-duo China Three Gorges Corporation Yichang 443002 China State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China

This study is focused on the effects of ecological factors （diameter and flexibility） and vegetation community composition on the drag coefficient related with vegetation. The single leafy shrub and three mixed communities （including shrub-grass, shrub-reed and reed-grass community） were studied. The flow velocity and water level were measured and used to calculate the drag coefficient based on the Bernoulli＇s equation, Darcy drag formula and the expression for the drag coefficient related with Darcy drag factor. The trend of the drag coefficient in the vertical direction was analyzed against flow depth, diameter, diameter P（eynolds number, flow depth Reynolds number and relative roughness height in different discharges. The results show that beside the dense leafy shrubs community, the vertical trend of the drag coefficient among other cases against flow depth, diameter, diameter Reynolds number, flow depth Reynolds number and relative roughness height can be approximately expressed by power law functions under different flow discharges. Moreover, in a mixed community with two plants with distinctly different ecological factors, the one with the most distinct variations of ecological factors determines the vertical trend of the drag coefficient; the other one only affects the magnitude of the drag coefficient. Furthermore, if the ecological factors of the vegetation in the vertical direction are kept almost not changed, the drag coefficient can be approximately regarded as a constant.

关键词： vegetated channel drag coefficient flume experiment

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

MODELING STUDY ON SEDIMENTATION CONFIGURATION IN FRONT OF THE DAM AND IN THE PRESSURE CONDUIT OF BOTTOM OUTLETS BY flume experiment

引用

International Journal of Sediment Research 1997年第3期 275-281页

作者： XU Guobin Senior Research Engineer, Tianjin Institute of Hydroelectric Investigation and Design and Research, Ministry of Water Resources. 60 Dongting Road, Hexi District, Tianjin 300222, P R. China. BAI Shilu Senior Research Engineer, Tianjin Institute o

This paper, taking Wanjiazhai Reservoir on the Yellow River as an example, develops the experimental method for determining sedimentation elevation in front of the dam and sedimentation configuration in the pressure conduit of bottom outlets by flume. The results obtained from the experiment are reasonable, so a new method is given to investigate sedimentation configuration in front of the dam and in the pressure conduit.

关键词： Sedimentation elevation in front of the dam Sedimentation configuration in the pressure conduit flume experiment Wanjiazhai Reservoir

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

experimental Simulation Study of the Dominant Enrichment Area of Terrestrial Organic Matter in the Shallow-Delta Sedimentary System of the Yacheng Formation in the Qiongdongnan Basin

引用

Acta Geologica Sinica(English Edition) 2022年第5期96卷 1693-1703页

作者： XU Xinde YANG Xibing QU Tong GAO Gang LIANG Gang LI Xing CNOOC China Limited Zhanjiang BranchZhanjiangGuangdong 524057China State Key Laboratory of Petroleum Resources and Prospecting China’s University of PetroleumBeijing 102249China College of Geosciences China’s University of PetroleumBeijing 102249China CNOOC China Limited Hainan BranchHaikou 570312China

Shallow-delta sedimentary systems receive both terrestrial and marine organic matter. As oil and gas exploration activities determine that the source rocks of the deep-water area of the Qiongdongnan Basin, northern South China Sea, are generally rich in and even dominated by terrestrial organic matter, this has led many researchers to examine the rules governing terrestrial organic matter enrichment in shallow-delta sea sedimentary systems. However, the deep burial of source rocks in deep-water areas and the relatively small amount of drilling undertaken have greatly restricted the study of these rules. In this study, the ‘forward modeling' research method was used to observe and analyze the deposition and preservation of terrestrial organic matter through flume experiments, where the depositional results were carefully depicted and sampled. The total organic carbon content of selected samples was measured and when combined with qualitative observations and quantitative comparison results, the dominant enrichment areas of terrestrial organic matter were identified. The experimental results show that the overbank parts of the delta front, the dune countercurrent surface, the low-lying parts, the delta front slope area and the shallow-prodelta sea area are where terrestrial organic matter is predominantly enriched. This provides an important basis and guidance for the prediction of the development areas of marine source rocks with terrestrial input in the deep-water areas of the Qiongdongnan Basin.

关键词： shallow-delta sea sedimentary system deep water area terrestrial organic matter flume experiment enrichment area Qiongdongnan Basin

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

experimental Investigation of the Response of Monopiles in Silty Seabed to Regular Wave Action

引用

China Ocean Engineering 2022年第1期36卷 112-122页

作者： HUANG Ting ZHANG Ji-sheng HOU Li-jun WANG Rong CHENG Ning Key Laboratory of Ministry of Education for Coastal Disaster and Protection Hohai UniversityNanjing 210098China College of Harbor Coastal and Offshore EngineeringHohai UniversityNanjing 210098China China Harbour Engineering Company Ltd. Beijing 100027China

Excessive displacement responses of monopiles affect the serviceability of offshore structures.Related to complicated pile−seabed−wave interactions,the actual behavior of monopiles in silty seabed under periodic wave action remains unclear,and relevant studies in the literature are limited.A series of experiments were conducted in a wave flume containing single piles in silty seabed with relative density of 0.77 subjected to regular waves.Two stages of wave loading were applied successively,accompanied by data recording which included pore water pressure,water surface elevation,pile head displacement,and pile strain.Development of pile-head displacement and pore pressure in silty seabed was the main focus,but the effects of pile diameter,pile type,and pile stiffness were also investigated.The experimental results indicate that,in silty seabed,piles of large diameter or with fins accelerate soil liquefaction,resulting in strengthened soil which allows a higher upper boundary of pore pressure.Using fins at deeper locations led to a quick failure of the piles,but the opposite result was observed with an increase in fin dimensions.Once pile-head displacement entered its rapid development period,the wave load calculated via the pile moment was an overestimation,especially for the piles of large diameter.

关键词： monopiles regular wave flume experiment pore water pressure finned pile silty seabed

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Modeling of breaching parameters for debris flow dams

引用

Journal of Mountain Science 2023年第10期20卷 2835-2851页

作者： RUAN He-chun CHEN Hua-yong CHEN Xiao-qing ZHAO Wan-yu CHEN Jian-gang WANG Tao JIANG Yao Wang Xi-an Li Xiang-ning LI Xiao YU Yun-han Key Laboratory of Mountain Hazards and Surface Processes Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China University of Chinese Academy of Sciences Beijing 100000China

The debris flow dam is a common type of barrier dams,which shows significant differences from other types of barrier dam such as landslide dam,moraine dam in their formation processes,dam body shapes,and internal compositions.The basic breaching parameters such as flood peak discharge are vital indicators of risk assessment.In this study,we elucidated the failure process of the debris flow dam through the flume experiment,and built the calculation equation of the breaching parameters by selecting critical factors.The result shows that the overtopping failure process of the debris flow dam is capable of forming significantly retrogressive scarps,and the failure process experiences three stages,the formation of the retrogressive scarp,the erosion of the retrogressive scarp,and the decline of the retrogressive scarp.Five factors used for establishing the calculation equations for peak discharge(Qp),final width(Wb)of the breach,and duration(T)of the debris flow dam failure are dam height(h),reservoir capacity(V),the fine grain content(P0.075)of the soil,the nonuniformity coefficient(Cu)of the soil,and the upper limit grain size(D90)of the soil,respectively.In the three equations,the correlation coefficients between Qp,Wb,T and the five factors were 0.86,0.70,0.63,respectively.The equations still need to be modified and verified in actual cases.

关键词： Debris flow dams Overtopping failure Breaching g parameters Peak discharge flume experiment

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Spatio-temporal deposition profile of an experimentally produced turbidity current with a continuous suspension supply

引用

International Journal of Sediment Research 2022年第3期37卷 299-306页

作者： Shun Nomura Giovanni De Cesare Mikito Furuichi Yasushi Takeda Hide Sakaguchi Mathematical Science and Advanced Technology JAMSTEC Plateforme de Constructions Hydrauliques EPFL Laboratory of Food Process Engineering ETH Headquarters JAMSTEC

A turbidity current is a turbulent, particle-laden gravity current that is driven by density differences resulting from the presence of suspended sediment particles. The current travels downslope, bearing a large amount of sediment over a great distance, and forms fluvial and submarine bedforms. Knowledge of the spatio-temporal deposition profile of turbidity-deposited sediment is important for a better understanding of sediment transport by turbidity currents. In the current study, the depositional process of experimentally produced quasi-steady turbidity currents in an inclined flume was investigated using an electrical-resistance-based depositmeter. It was found that the amount of sediment deposited along the flume bottom increases linearly with time at a specific rate, and decreases exponentially in the downstream direction. Inspired by this observation, the mass conservation law was modified for the suspension layer and a simple theoretical model was proposed involving two parameters, the initial sedimentation rate and the decay constant. The proposed model reproduces the observed data from the flume experiment with high accuracy, and is consistent with the sediment transport distance of a natural example, the Bengal Fan. It was concluded that the two parameters that govern the sedimentation process are the key to estimating the deposition profile of fluvial systems.

关键词： Turbidity current Deposition process Mass conservation law Electrical-resistance-based depositmeter Spatio-temporal investigation flume experiment

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Numerical and experimental Analysis of A Vertical-Axis Eccentric-disc Variable-Pitch Turbine(VEVT)

引用

China Ocean Engineering 2020年第3期34卷 411-420页

作者： CHEN Hai-long JING Feng-mei LIU Heng-xu DING Hua-qiu KONG Fan-kai SHI Jian Yantai Research Institute and Graduate School Harbin Engineering UniversityYantai 264006China School of Mechanical Engineering Beijing Institute of Petrochemical TechnologyBeijing 102617China College of Shipbuilding Engineering Harbin Engineering UniversityHarbin 150001China College of Mechanical and Electrical Engineering Harbin Engineering UniversityHarbin 150001China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China

A combined experimental and numerical investigation is carried out to study the performance of a vertical-axis eccentric-disc variable-pitch turbine(VEVT).A scheme of eccentric disc pitch control mechanism based on doubleblock mechanism is proposed.The eccentric control mechanism and the deflection angle control mechanism in the pitch control structure are designed and optimized according to the functional requirements of the turbine,and the three-dimensional model of the turbine is established.Kinematics analysis of the eccentric disc pitch control mechanism is carried out.Kinematics parameters and kinematics equations which can characterize its motion characteristics are derived.Kinematics analysis and simulation are carried out,and the motion law of the corresponding mechanical system is obtained.By analyzing the force and motion of blade of VEVT,the expressions of the important parameters such as deflection angle,attack angle and energy utilization coefficient are obtained.The lateral induced velocity coefficient is acquired by momentum theorem,the hydrodynamic parameters such as energy utilization coefficient are derived,and the hydrodynamic characteristics of VEVT are also obtained.The experimental results show that the turbine has good energy capture capability at different inflow velocities of different sizes and directions,which verifies that VEVT has good self-startup performance and high energy capture efficiency.

关键词： vertical axis variable pitch turbine eccentric disc pitch control mechanism kinematics analysis hydraulic analysis flume experiment

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Scour around submarine pipes due to high-amplitude transient waves

引用

Water Science and Engineering 2020年第2期13卷 154-161页

作者： Hassan Vosoughi Hooman Hajikandi Department of Civil Engineering Central Tehran BranchIslamic Azad UniversityTehran ***Iran

Estimation of scour dimensions below submarine pipelines is a vital step in designing offshore infrastructure.Extreme events like tsunami waves produce strong erosive forces below the underwater pipes,apt to create scour holes,jeopardizing the safety of the structure.Despite the importance of this issue,previous studies have mainly focused on steady flow cases,and the scour pattern below submarine pipes induced by high-amplitude transient waves has rarely been investigated.This paper reports the results of 40 experimental runs on transient wave-induced scour below a model pipe in a laboratory flume under a variety of initial conditions.The variables included the bed particle size and gradation,initial water depth,wave height,and slope of the bed layer.Waves were generated by a sudden release of water from a sluice gate,installed in the middle of the flume.A pressure transducer data acquisition system was used to record the wave heights at different time steps.The results indicate that,with a shallower initial depth of flow,the scour depth is relatively large.It was also found that there exists a direct correlation between the induced wave height and the size of the scour hole.It was observed that,in clear water conditions,the size of the scour hole in coarse sediments is smaller,while in live-bed conditions,larger scour holes are created in coarser sediments.It was also observed that at high wave amplitudes,the live-bed conditions are dominant,and consequently the bed elevation is altered.

关键词： Submarine pipe Scour hole Transient wave flume experiment Live-bed condition Sediment

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：