Wave Scattering by Double Slotted Barriers in A Steady Current： Experiments   总被引：1，自引：1，他引：0  

Zhenhua HUANG 《中国海洋工程》2008,22(2):205-214

The adoption of slotted breakwaters can be an ideal option in the protection of very large near-shore floating struc-trees that may extend offshore to a considerable water depth. In this paper, we experimently investigated the behaviour of wave transmission and reflection coefficients of double slotted barriers in the presence of a steady opposing current. The experimental results show that opposing currents have only minor effects on wave reflection, but can significantly reduce the wave transmission through double slotted barriers. The experimental results suggest that coastal currents should be taken into consideration for an economical design of slotted breakwaters.  相似文献   

Experiments on wave transmission coefficients of floating breakwaters   总被引：1，自引：0，他引：1  

G.H. Dong  Y.N. Zheng  Y.C. Li  B. Teng  C.T. Guan  D.F. Lin 《Ocean Engineering》2008,35(8-9):931-938

To find a simple, inexpensive, and effective type of floating breakwater for deep-sea aquaculture, we studied three types of structures: the single box, the double box, and the board net. We conducted two-dimensional physical model tests in a wave-current flume in the laboratory to measure the wave transmission coefficients of the three types of breakwaters under regular waves with or without currents. Based on the initial comparison of the wave transmission coefficients, we proposed the use of the board-net floating breakwater for use with fish cages; we then conducted detailed experiments to examine how wave transmission coefficients are affected by several factors, including the width of the board, the row number of the net, the rigidity of the board, and the current velocity. The experimental results show that the board-net floating breakwater, which is a simple and inexpensive type of structure, can effectively protect fish and fish cages and may be adopted for aquaculture engineering in deep-water regions.  相似文献   

A Linear Theory for Wave Scattering by Double Slotted Barriers in Weak Steady Currents     

Zhenhua HUANG  Chunrong LIU 《中国海洋工程》2008,22(2):215-226

Recent experimental results have shown that the presence of a steady current can significantly reduce the energy of transmitted waves. In this paper, a theory is developed to study the wave scattering by single or double vertical slotted barriers in the presence of a weak uniform current. The quasi-linear theory is based on an eigenfunction expansion method. Comparisons between theory and existing experimental results for both single slotted barrier and double slotted barriers show satisfactory agreements. In consideration of wave propagation in a weak current it is found that the friction factor used to characterize the head loss at the slotted barrier depends on both the geometry of the slotted barrier and the strength of the steady current.  相似文献   

Bragg reflection of water waves by multiple submerged semi-circular breakwaters     

《Applied Ocean Research》2016

This study examines the Bragg reflection of water waves by multiple submerged semi-circular breakwaters. The multipole expansions combined with the shift of polar coordinates are used to develop full linear potential solutions of the problem. In the full solutions, the obliquely and normally incident waves are independently considered. Experimental tests are carried out to measure the reflection and transmission coefficients of the breakwaters at different wave periods and body spacings. The analytical results are in reasonable agreement with the experimental data. The peak reflection coefficient of multiple submerged semi-circular breakwaters and the bandwidth of Bragg reflection are carefully examined by numerical examples. Some significant results for practical application are discussed.  相似文献   

斜坡堤典型胸墙波浪力影响因素的试验与分析     

李雪艳  付聪  范庆来  王岗 《海洋科学》2015,39(12)

为探求斜坡堤典型胸墙迎浪面所受波浪力大小的影响因素,设计前仰式、深弧式、后仰式和直立式四种结构型式胸墙进行相关的物理模型试验。通过在典型胸墙迎浪面间隔布置压力测点获取所受波浪压力,并将其进行积分求和得到胸墙所受波浪力,进而讨论相对波高(H/d)、相对波长(L/d)、斜坡坡度和胸墙结构型式对波浪力的影响。试验结果表明：相对波高与相对波长对胸墙所受波浪力影响显著。波浪力随着相对波高的增大而增大,随着相对波长的增大呈现先增大—后减小—再增大的变化趋势。波浪力随着斜坡坡度的增大而减小。斜坡堤弧形胸墙所受波浪力明显大于直立式胸墙所受波浪力;在斜坡堤弧形胸墙中,前仰式胸墙受力较其余两种型式胸墙受力小。研究结果将加深波浪对斜坡堤胸墙作用力的理解,为后续工程设计提供理论指导。  相似文献   

Toe Structure Stability of Sloping Breakwater     

吴中  嵇才苏 《中国海洋工程》2003,17(2)

1 .IntroductionTheslopingbreakwateriswidelyusedintheprotectionofcoastalstructures ,withrubblemoundtoebermbuiltatthefootofthewave attackingslope .Thefunctionofarubblemoundtoestructureis ,inadditiontodecreasingthequantityofmainarmorstoneused ,toprovidestaticsupporttothemainarmorlayer,avoidingtherollingdownofmainarmorstonesandprotectingtheapronstonesfromero sion .TheweightoftoebermstonesisdecidedaccordingtotheCodeofBreakwaterDesignandBuildingformulatedbytheMinistryofCommunicationsofChina .When…  相似文献   

Wave interaction with twin plate wave barrier   总被引：3，自引：0，他引：3  

S. Neelamani  T. Gayathri 《Ocean Engineering》2006,33(3-4):495-516

The wave transmission and reflection characteristics and wave induced pressures on single surface plate and twin plate barriers were investigated experimentally for a wide range of wave heights and periods in regular and random waves. Seven different spacing between the plates were tested. It is found in general, hydrodynamically the twin plate is better than the single surface plate to reduce the wave transmission and increase the wave reflection. It is found that the transmission coefficient of twin plate reduced from 0.8 to 0.3 when the relative plate width is increased from 0.18 to 0.84. Transmission coefficient of twin plate barrier shows oscillating behavior, when relative plate width is increased due to blocking and pumping effect. The reflection coefficient increased from 0.25 to 0.65, when the relative width of the plate is increased from 0.18 to 0.84. The increase in spacing between the plates was also found to increase the reflection coefficient. The transmission coefficient, K_t for 98% probability of non-exceedence was found to be minimum and is about 0.60 when the relative spacing between the plate is about 0.12, compared to K_t=0.76 for single surface plate. The reflection coefficient for 98% probability of non-exceedence was found to exceed 0.66 for single surface plate, whereas it is 0.73 for twin plate with relative spacing of about 0.40. From the investigation with wide range of input parameters, it is found that the twin plate barrier needs to be designed for highest 98% pressure ratio of 2.0, which is equal to the static pressure induced by the design incident wave height.  相似文献   

斜堤护面块体在斜向波作用下的稳定性     

俞聿修  朱传华  柳淑学 《海岸工程》2001,20(4):1-6

通过三维模型试验 ,研究了在斜向波作用下 ,扭工字块体、钩连块体、四脚空心方块和抛填块石等 4种块体在斜向波浪作用下的稳定性 ,给出了实用计算方法。  相似文献   

中高渗倾斜地层与水平地层中CO2地质封存的差异性对比     

王福刚  郭兵  杨永智  汪芳  田海龙 《地球科学与环境学报》2020,(2):246-255

CO2地质封存是减少CO2向大气排放,缓解温室效应的有效手段之一。由于构造和成岩作用,倾斜地层在自然界中普遍存在,研究倾斜地层对CO2封存量及安全性的影响具有实际意义。依托新疆准噶尔盆地阜康凹陷某CO2地质封存示范工程,采用数值模拟方法,分析了中高渗CO2储层地层倾角变化对CO2地质封存过程的影响。结果表明:CO2注入将导致近井区域地层压力显著升高;中高渗倾斜地层与水平地层相比,在地层压力分布、CO2侧向运移距离、CO2注入速率和总封存量等方面均存在明显差异。相比于水平地层,由于地层倾角的存在,倾斜地层压力呈不对称分布,CO2侧向运移距离显著加大。倾斜地层中压力传递和消散过程与水平地层差异显著,受此影响,倾斜地层与水平地层CO2的总注入量差值随时间呈非单调性变化。在注入初期,倾斜地层CO2的总注入量小于水平地层,随着注入时间延长,倾斜地层CO2的总注入量逐渐接近并超过水平地层;注入20年后,相较于水平地层,倾斜地层倾角越大越有助于增加CO2的总注入量,这一研究结果与前人基于低渗倾斜地层的研究结论正好相反。地层倾角的存在会促进CO2向浅部运移,倾角越大,CO2向浅部含水层和大气泄露的风险越大。因此,在CO2地质封存场地选址中,应充分考虑倾斜地层对封存效率及安全性的影响。  相似文献   

基于辽宁省数字高程模型的坡地资源分级     

纪瑞鹏  张玉书  冯锐  陈鹏狮  张淑杰  武晋雯 《气象与环境学报》2007,23(6):11-14

土地的坡度和高程是决定耕地质量与合理利用的重要因素,对合理规划土地用途尤其是退耕还林还草具有重要意义。数字高程模型(DEM)为土地资源调查、退耕还林还草工程的实施提供了有效的辅助工具。依托ArcGIS软件平台,利用辽宁省1∶250000比例尺的地形图,建立空间分辨率为100 m的数字高程模型,基于DEM完成了辽宁省坡地资源信息的提取与分级,并对坡地资源的利用规划进行分析,为辽宁省土地规划和生态省建设提供了自动、客观、高精度的基础数据资料。  相似文献