THE HYDRODYNAMICS OF A DISTENSIBLE WAVE ENERGY CONVERTER

可膨胀波能转换器的流体动力学

• 批准号: EP/F030975/1
• 负责人: John Chaplin
• 金额: $ 54.81万
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FF030975%2F1
• 关键词: HYDRODYNAMICS; DISTENSIBLE; WAVE; ENERGY; CONVERTER

The Anaconda is a new concept for wave energy conversion. It is just a rubber tube in the sea, full of water, closed at both ends, anchored head to waves. It is squeezed or enlarged locally by pressure variations that run along its length due to the waves. Squeezing a water-filled rubber tube starts a bulge wave running. The bulge wave travels at a speed that is determined by the geometry and material properties of the tube. The Anaconda is designed so that its bulge wave speed is close to the speed of the water waves above. In these conditions the bulges grow as they travel along the tube, gathering wave energy. Inside the tube, the bulge waves are accompanied by a periodically reversing flow. One way of extracting power from the Anaconda is to use a pair of duck-bill valves to convert this into a rectified flow past a turbine between high and low pressure reservoirs. We have proved the concept of the Anaconda at a scale of about 1:85 in a laboratory wave flume. At this scale a large part of the converted wave energy is lost in heating up the thin wall rubber from which the tube is made, and in the turbulent flow through the valves. Nevertheless, the model absorbed all of the incident wave power over a front equal in width to as much as 5 times its diameter. A power take-off system accounted for about 20% of this, corresponding to more than 250kW for a 7m diameter Anaconda, 150m long, in waves 2m high. At larger scale, energy losses would be much less significant and the proportion of useful power conversion much higher. A device rated at 1MW would contain about 100 tonnes of rubber, making the Anaconda an exceptionally light wave energy converter for its power.When it comes to predictions, the Anaconda is like no other marine vessel or structure. It has some features in common with Pelamis, but it is much more compliant, has many more degrees of freedom, and does not necessarily follow the motion of the water surface. Our mathematical models of it are rather basic, and in many respects are not in very good agreement with laboratory measurements. The aim of this research is to develop a better understanding of the hydrodynamics of the device, and formulate a comprehensive and validated numerical with which to make more reliable estimates of full scale performance. Experiments will be carried out at scales of 1:28 and 1:14, with tubes of diameters 0.25m and 0.50m, at which rubber hysteresis losses will be proportionately much lower than at smaller scale. Three types of experiments are planned, to provide measurements of internal pressures, tube displacements, radiated waves, mooring forces, and absorber power:(1) measurements in still water with bulge waves generated mechanically at one end of the tube, and absorbed at the other,(2) measurements in regular and irregular waves,(3) measurements in extreme waves.The results will provide insights into the mechanics of the device and support the development of a numerical model that will for the first time include the effects of wave radiation and other factors so far neglected. Some features of the work will be relevant to other examples of wave interactions with compliant surfaces.

蟒蛇是波浪能转换的新概念。它只是海里的一根橡胶管，充满了水，两端封闭，头靠在波浪上。由于波浪的作用，它的长度受到压力变化的挤压或局部放大。挤压装满水的橡胶管，就会产生膨胀波。膨胀波的传播速度由管子的几何形状和材料特性决定。蟒蛇的设计使它的膨胀波速度接近上面水波的速度。在这种条件下，这些凸起在管道中移动，收集波浪能量。在管道内部，膨胀波伴随着周期性的反向流动。从蟒蛇中提取能量的一种方法是使用一对鸭嘴阀将其转化为经过高压和低压水库之间的涡轮的整流。我们已经在实验室波浪水槽中以1:85的比例证明了蟒蛇的概念。在这种规模下，大部分转换的波能在加热制造管子的薄壁橡胶和通过阀门的湍流中损失掉。然而，该模型吸收了所有入射波的能量，其宽度相当于其直径的5倍。其中动力输出系统约占20%，相当于一条直径7米、长150米、浪高2米的蟒蛇所需的功率超过250千瓦。在更大的范围内，能量损失将不那么重要，而有用的能量转换的比例将高得多。一个额定功率为1兆瓦的装置将包含大约100吨橡胶，使蟒蛇成为一个特殊的光波能量转换器。说到预测，“蟒蛇”号与其他任何海洋船只或建筑都不一样。它与Pelamis有一些共同的特点，但它更柔顺，有更多的自由度，并且不一定跟随水面的运动。我们的数学模型是相当基础的，在许多方面与实验室测量结果不太一致。本研究的目的是为了更好地了解该装置的流体动力学，并制定一个全面和有效的数值，以便对全尺寸性能进行更可靠的估计。实验将在1:28和1:14的比例下进行，管子直径分别为0.25m和0.50m，在此比例下橡胶滞回损失将比小比例下小得多。计划进行三种类型的实验，以测量内部压力、管道位移、辐射波、系泊力和吸收力：(1)在静水中测量，在管道一端机械产生凸起波，在另一端吸收凸起波；(2)在规则波和不规则波中测量；(3)在极端波中测量。这些结果将提供对该装置力学的深入了解，并支持数值模型的发展，该模型将首次包括波辐射和其他迄今为止被忽视的因素的影响。这项工作的一些特征将与其他波与柔顺表面相互作用的例子相关。

项目成果

Predictions of aneurysm formation in distensible tubes: Part B-Application and comparison of alternative approaches

• DOI: 10.1016/j.ijmecsci.2013.02.008
• 发表时间: 2013-05-01
• 期刊: INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
• 影响因子: 7.3
• 作者: Bucchi, Andrea;Hearn, Grant E.
• 通讯作者: Hearn, Grant E.

Performance of a distensible-tube wave attenuator in a slender focusing channel

细长聚焦通道中可伸缩管波衰减器的性能

• DOI: 10.1007/s40722-023-00297-8
• 发表时间: 2023
• 期刊: Journal of Ocean Engineering and Marine Energy
• 影响因子: 1.9
• 作者: Mendes A

Assessing the efficiency of a distensible-tube wave attenuator at three different scales considering aero and hydro-elastic effects

考虑空气和水弹性效应，在三种不同尺度下评估可膨胀管波衰减器的效率

• DOI: 10.1016/j.apor.2023.103792
• 发表时间: 2023
• 期刊: Applied Ocean Research
• 影响因子: 4.3
• 作者: Mendes A

Predictions of aneurysm formation in distensible tubes: Part A-Theoretical background to alternative approaches

• DOI: 10.1016/j.ijmecsci.2013.02.005
• 发表时间: 2013-06-01
• 期刊: INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
• 影响因子: 7.3
• 作者: Bucchi, Andrea;Hearn, Grant E.
• 通讯作者: Hearn, Grant E.

Delay or removal of aneurysm formation in the Anaconda wave energy extraction device

• DOI: 10.1016/j.renene.2012.10.050
• 发表时间: 2013-07
• 期刊: Renewable Energy
• 影响因子: 8.7
• 作者: A. Bucchi;G. Hearn