Numerical Simulation of the effect of wave characteristics on PTO of Point Absorber Wave Energy Converter
Numerical Simulation of the effect of wave characteristics on PTO of Point Absorber Wave Energy Converter
复制标题
波浪特性对点吸收式波浪能转换器PTO影响的数值模拟
DOI：
10.5957/tos-2022-010
复制
发表时间：
2022
期刊：
影响因子：
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通讯作者：
Mirjam Furth
中科院分区：
文献类型：
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作者：
A. Hamada;Abigail Rolen;W. McCullough;Mirjam Furth
海洋目前是一种极大且不发达的可再生能源。最近对蓝色经济的兴趣导致科学界增加了对可持续海洋能源选择的研究，例如PointWave能量转换器(WEC)。这些设备通过浮标的激发振荡运动来获取波能，浮标连接到动力输出系统(PTO)。在过去的几十年里，这些设备的发展得到了推动，但它们仍然落后于其他可再生能源技术。德克萨斯A&M大学的Furthlab通过在非线性斯托克斯-II波产生中测试不同的浮标形状和纵横比，表明具有低长径比的椭球浮标形状是提取波浪能量的良好候选形状。本文是我们研究的下一步，数值研究了改变波动特性，如振幅、频率和速度，对椭球浮标系统发电能力的影响。在OpenFOAM中对所选浮标进行了三维非定常雷诺平均纳维斯托克斯(URANS)模拟，并结合动态网格模块处理浮标的升沉运动。另外，利用弹簧和阻尼器的受迫振子机构对PTO系统进行了补偿。浮标的位移和频率响应以及功率效率的比较表明，使用椭球体WEC可以最大限度地提高能量输出的最佳工作海况。结果表明，采用直径为1m、长度为0.5m的椭球型浮标进行功率提取的最佳波浪条件为：波长大于4m，波高小于0.15m，波速在0.07~0.12m/S之间。
The ocean is currently an extremely large and under-developed source of renewable energy. The recent interest in the Blue Economy has led the scientific community to increase investigations in sustainable oceanic energy options, such as PointWave Energy Converters (WEC). These devices harvest the wave energy using the excited oscillatory motion of the buoy, which is connected to a Power Take-Off system (PTO). During the last decades, the development of these devices has been boosted but they are still behind other renewable energy technologies. The Furthlab at Texas A&M University has showed that the spheroid buoy shape with a low length to diameter ratio is a good candidate shape to extract wave energy, by testing different buoy shapes and aspect ratios at a non-linear Stokes-II wave generation. This paper is the next step in our research and numerically investigates the effect of changing the wave characteristics, such as amplitude, frequency, and speed, on the power-generating ability of the spheroid buoy system. Three-dimensional Unsteady Reynolds-Averaged Navier-Stokes (URANS) simulations of the selected buoy were performed in OpenFOAM with the integration of a dynamic mesh module to handle the heave motion of the buoy. In addition, the PTO system was compensated with a forced oscillator mechanism of spring and damper. A comparison between the buoy’s displacement and frequency responses, and power efficiency showed the optimal operating sea state to maximize energy output using the spheroid WEC. The results conclude that the best wave conditions to maximize the power extraction efficiency using a spheroid buoy with a diameter of 1 m and length of 0.5 m are wave length greater than 4 m, wave height less than 0.15 m, and wave speed between 0.07 and 0.12 m/s.