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1.
本文对振荡水柱波能装置的水柱做了时域计算，研究了内水柱在气室处于封闭状态、有阻尼状态和无阻尼状态下的动力响应。得出了相应的波浪载荷，并对波能装置的几种保护措施作了探讨。数值结果表明，带有阻尼的气室不能有效地阻止内水柱的运动，将使结构承受危险载荷的打击；全封闭的气室能有效地阻止内水柱的运动，但可能使气室里产生高压；收缩口与破浪锥联合作用，可以消耗水柱的动能，大大地减少载荷，是一种有前途的保护措施。 相似文献
2.
Investigation on the Oscillating Buoy Wave Power Device 总被引：4，自引：0，他引：4
An oscillating buoy wave power device (OD) is a device extracting wave power by an oscillating buoy. Being excited by waves, the buoy heaves up and down to convert wave energy into electricity by means of a mechanical or hydraulic device. Compared with an Oscillating Water Column (OWC) wave power device, the OD has the same capture vvidth ratio as the OWC does, but much higher secondary conversion efficiency. Moreover, the chamber of the OWC, which is the most expensive and difficult part to be built, is not necessary for the OD, so it is easier to construct an OD. In this paper, a nu-merical calculation is conducted for an optimal design of the OD firstly, then a model of the device is built and, a model test is carried out in a wave tank. The results show that the total efficiency of the OD is much higher than that of the OWC and that the OD is a promising wave power device. 相似文献
3.
The motion and the drift force of a floating OWC (oscillating water column) wave energy device in regular waves are studied taking account of the oscillating surface-pressure due to the pressure drop across the duct of the air chamber. The potential problem inside the chamber is formulated by making use of the Green integral equation associated with the Rankine-type Green function while the outer problem with the Kelvin-type Green function. The added mass, wave damping and excitation coefficients as well as the motion and drift force of the OWC device are calculated for various values of parameter related to the pressure drop. 相似文献
4.
为提升波能转换装置的经济竞争力,针对非对称垂荡式振荡水柱（OWC）波能转换装置,基于势流理论和匹配特征函数展开法,通过引入盖根堡多项式近似表征结构尖角附近的流场奇异性行为,深入研究后墙吃水深度（非对称）、墙体厚度和线性弹簧系数对垂荡式OWC装置的波能转换效率、透射系数、气室内平均液面高程等水动力参数的影响规律。研究结果显示,后墙吃水深度及墙体厚度的增加会提升装置在长波区域的高效转换能力,并且显著提高结构物整体阻波防浪性能;线性弹簧的出现,能调节水柱振荡和结构垂荡运动响应之间的相位差,从而有效拓宽垂荡式OWC装置的高效频率带。 相似文献
5.
基于VOF模型的OWC气室波浪场数值分析 总被引：1，自引：0，他引：1
近年来,振荡水柱形式在波能转换装置中得到了广泛应用,由于波况不同,需对气室加以研究并对其形状参量进行优化,从而使空气流速和能量转换达到最大值.利用基于VOF模型建立二维数值波浪水槽,将数值计算的振荡水柱在气室内的升沉运动与物理模型试验进行比较,验证其正确性,并将OWC气室的研究手段予以推广. 相似文献
6.
Oscillating Water Column (OWC) is one of the pioneer devices in harnessing wave energy; however, it is not fully commercialized perhaps due to the complicated hydrodynamic behavior. Previous studies are significantly devoted to OWC devices located in nearshore and coastal regions where incident wave energy would experience dissipation more than offshore. In this paper, a 1:15 scaled fixed offshore OWC model is tested in a large towing tank of National Iranian Marine Laboratory. Wave spectrum shape effect on the efficiency of the OWC model is addressed. Moreover, the paper investigates the effects of the geometric and hydrodynamic factors on OWC device efficiency and uncovers new points in nonlinear interaction occurring inside the chamber; i.e. sloshing. The results indicate that shape of the spectrum inside the chamber is affected by the type of incident wave spectrum, especially for long waves. Pierson–Moskowitz spectrum leaded to higher efficiency rather than JONSWAP spectrum at longer incident wave periods. According to efficiency analysis, increasing wave height may lead to air leakage from the chamber followed by vortex generation, which is a reason for decreasing the efficiency of the OWC device. Furthermore, no shift in the resonant period of the OWC model, due to wave height increase, was observed at the opening ratios equal or smaller than 1.28%. Spectral analysis of water fluctuation inside the OWC chamber illustrates two modes of sloshing. The first mode can be seen at short period waves while the second mode is visible at long period waves. The sloshing modes approximately vanish by increasing draft value. 相似文献
7.
Structural Design and Protective Methods for the 100 kW Shoreline Wave Power Station 总被引：2，自引：0，他引：2
1 .IntroductionThe 1 0 0kWshorelinewavepowerstationofChinaisanOscillatingWaterColumn (OWC)wavepowerdeviceintegratedtoanelectricgrid .ItislocatedattheZhelangTown ( 2 2°39’Nand 1 1 5°34’E) ,ShanweiCityofGuangdongProvince .Theresearchanddevelopmentofthe 1 0 0kWOWCshore linewavepowerstationissupportedbyChina′sNationalKeyTechnologiesR&DPrograminthe 9thfive yearplan .TheconstructionofthestationstartedinJune 1 998andwascompletedinFebruary2 0 0 1 .Uptonow ,ithasbeenoperatingfor2years … 相似文献
8.
Oscillating Water Column (OWC) wave energy converting system is one of the most widely used facilities all over the world.The air chamber is utilized to convert the wave energy into the pneumatic energy.The numerical wave tank based on the two-phase VOF model is established in the present study to investigate the operating performance of OWC air chamber.The RANS equations,standard k-ε turbulence model and dynamic mesh technology are employed in the numerical model.The effects of incident wave conditions and shape parameters on the wave energy converting efficiency are studied and the capability of the present numerical wave tank on the corresponding engineering application is validated. 相似文献
9.
An information system for ocean wave resources and its application to wave power utilizationare indtroduced.It can manage,analyze and process the data in the monthly report of ocean wave observa-tion records of the State Ocean Administration,and can provide various kinds of curves and numericalcharacters of statistics.This system has been put into utility in Guangzhou Institute of Energy Conversion(GIEC),the Chinese Academy of Sciences since 1996.An application example is given of theinverstigation and analysis on ocean wave resource of the Nan Ao Island,Guangdong Province,where a100 kW onshore OWC(oscillating water column)wave power station will be built.The wave power distri-bution is obtained in different wave directions for different wave periods.It is found that 70 percent of thewave power comes from the direction of ENE,and more than 95 percent of the wave power is related withdirection E.The average wave power density is about 3 kW/m,and more than 80 percent of the wavepower is distributed in the 相似文献
10.
基于废旧轮胎再利用及研发简易且低廉的施工方法与维护成本,本研究以规则波水工模型试验研究提出应用于港口码头的多孔隙弹性帷幕的初步理念。利用模型车轮胎以模块化方式组装成弹性帷幕后安装于码头前壁,研究多种周期波浪作用及不同消波室纵深对波浪反射率的影响。实验结果表明,简单的单一消波室多孔隙弹性帷幕对短周期波浪的消波效果较显著,消波室纵深较大者反射率较低,但可能引致水体振荡,后续可再强化消波室的消能效果。未来如能妥善研究废旧轮胎应用于多孔隙弹性帷幕消波结构物的施工与维修方法,除可缓解废旧轮胎处理给环境带来的压力外,也提供一种可用于简易渔港的施工简单、维修容易且资源再利用的消能结构物,该工程技术亦可输出至发展中国家,符合可持续发展观。 相似文献
11.
This paper deals with the evaluation of the natural frequencies in heave motion of a single floating Oscillating Water Column device along with the natural frequencies of the water column inside the oscillating chamber. Two types of OWCs are examined, a simple-type device, consisting of a partially immersed toroidal body and a novel-type device, consisting also of a partially immersed toroidal body supplemented however by a coaxial interior truncated cylinder moving in phase with the outer chamber, thus forming a floating unit. Numerical results are given concerning the three boundary value problems, namely, the diffraction, the motion- and the pressure- dependent radiation problems, obtained through an analytical solution method using matched axisymmetric eigenfunction expansion formulations. The effect of the air pressure distribution inside the oscillating chamber on the natural frequencies in heave motion of the two examined types of OWCs and on the natural frequency of the water column motion inside the chamber, is presented and discussed thoroughly. It is demonstrated that the heave natural frequencies are strongly dependent on the type of the examined OWC and the device’s inner air pressure and should be taken into consideration when designing a floating OWC device. 相似文献
12.
Understanding the hydrodynamic interactions between ocean waves and the oscillating water column (OWC) wave energy converter is crucial for improving the device performance. Most previous relevant studies have focused on testing onshore and offshore OWCs using 2D models and wave flumes. Conversely, this paper provides experimental results for a 3D offshore stationary OWC device subjected to regular waves of different heights and periods under a constant power take–off (PTO) damping simulated by an orifice plate of fixed diameter. In addition, a 3D computational fluid dynamics (CFD) model based on the RANS equations and volume of fluid (VOF) surface capturing scheme was developed and validated against the experimental data. Following the validation stage, an extensive campaign of computational tests was performed to (1) discover the impact of testing such an offshore OWC in a 2D domain or a wave flume on device efficiency and (2) investigate the correlation between the incoming wave height and the OWC front wall draught for a maximum efficiency via testing several front lip draughts for two different rear lip draughts under two wave heights and a constant PTO damping. It is found that the 2D and wave flume modelling of an offshore OWC significantly overestimate the overall power extraction efficiency, especially for wave frequencies higher than the chamber resonant frequency. Furthermore, a front lip submergence equal to the wave amplitude affords maximum efficiency whilst preventing air leakage, hence it is recommended that the front lip draught is minimized. 相似文献
13.
In order to study the effects of coastline on wave power absorption, we describe here a linearized theory of an oscillating water column (OWC) installed on a straight coast. The sea depth is assumed to be constant and the coast is a vertical cliff. The column is a vertical circular cylinder half embedded in the cliff and open on the seaside. Forced by incident waves from any direction, the water surface inside pushes the dry air above through a Wells turbine system to generate power. Carrying out the linearized theories of radiation and diffraction analytically, we calculate the coefficients of apparent mass and radiation damping, and the chamber pressure. Optimum absorption efficiency is examined under the constraint of constant chamber volume. Results are compared with a parallel study of an OWC installed either offshore or at the tip of a thin breakwater. 相似文献
14.
15.
Wave Motion Compensation Scheme and Its Model Tests for the Salvage of An Ancient Sunken Boat 总被引：5，自引：0，他引：5
1 .IntroductionIt is always hopedthat sunken merchant vessels would resume their ship performances after sal-vage ,that ancient sunkenships of archeological value would be salvagedinits entirety withlittle harmtothe cultural relics ,andthat warships with … 相似文献
16.
Control strategies for the Clam Wave Energy Device 总被引：1，自引：0，他引：1
A promising wave energy device being currently investigated is the ‘clam’. The clam extracts energy by pumping air through a specially designed (Wells) turbine. Although operation of the Wells turbine does not require a rectified air flow, some additional control will be necessary to optimize the phase of the clam motion for good efficiencies. An examination of the equation of motion in the time domain suggests the possibility of phase control by mechanical, power take-off, or pneumatic latching. Latching can be shown to increase the efficiency of the device in the longer wavelengths of the wave spectrum, i.e. those of high incident wave power. Equivalently latching could be used to keep the device efficiency high while reducing its size, possibly resulting in cheaper power extraction. 相似文献
17.
Wave Energy Converters (WECs) have excellent potential as a source of renewable energy that is yet to be commercially realised. Recent attention has focused on the installation of Oscillating Water Column (OWC) devices as a part of harbor walls to provide advantages of cost–sharing structures and proximity of power generation facilities to existing infrastructure. In this paper, an incompressible three–dimensional CFD model is constructed to simulate a fixed Multi–Chamber OWC (MC–OWC) device. The CFD model is validated; the simulation results are found to be in good agreement with experimental results obtained from a scale physical model tested in a wave tank. The validated CFD model is then used for a benchmark study of 96 numerical tests. These investigate the effects of the PTO damping caused by the power take–off (PTO) system on device performance. The performance is assessed for a range of regular wave heights and periods. The results demonstrate that a PTO system with an intermediate damping can be used for all chambers in the MC–OWC device for most wave period ranges, except for the long wave periods. These require a higher PTO damping. An increased incident wave height reduces the device capture width ratio, but there is a noticeable improvement for long wave periods. 相似文献
18.
本文对同轴双浮子波能发电装置进行了深入研究。采用Fortran语言对AQWA进行二次开发,并施以线性及非线性PTO反力,实现了装置的运动模拟,获得了双浮子装置的水动力特性及捕能情况。研究表明,波浪周期及内外浮子质量对装置获能影响显著,建议选用质量比为0.8的双浮子装置,并将其放置于周期与外浮子固有周期接近的海域中以实现最优捕能。 相似文献
19.
为了解决振动水柱式波浪能转换装置收集多向波浪问题,本文设计了半球形多向聚合波道振荡水柱气室结构,以适合远海单点波浪能采集和发电。在规则波正向入射条件下,基于流体仿真分析软件(FLUENT)、流体动力学连续性假设和粘性不可压缩流体动量守恒的运动方程(Navier-Stokes方程)建立半球形振荡气室和三维数值波浪水槽模型。仿真结果表明:增设气室后壁,合理设计波道开口角度实现多向迎波捕获波浪能,优化前壁形状可降低波浪触底反射带来的能量耗散,同时提高了气室内空气压强和出气口速度,有效提升波浪能俘获效率,为后续发电的二次能量转换提供高效的空气动力。 相似文献
20.
OWC装置的结构形式繁多,共振周期也各不相同,全面合理地评价OWC装置的工作性能具有重要的现实意义。为优化OWC装置的工程选型,文章基于主客观权重集成法,分别采用层次分析法和熵值法计算峰值波能转换效率、一级衰减和二级衰减3个指标的主观权值和客观权值,并通过优化模型进行组合,从而确定综合权值;利用3个指标的综合权值,对4种不同结构的OWC装置的平均波能转换效率进行评分,并对评分结果进行验证和分析。研究结果表明:在所选的4种装置结构中,圆截面U-OWC的评分最高,即具有最高的平均波能转换效率;与传统OWC结构相比,U-OWC结构的平均波能转换效率较高,在实际工程中有更好的表现,在满足条件时宜优先采用。 相似文献