Abstract

Renewable energies could be a good solution to the problems associated with fossil fuels. The storage of wind energy by means of small-scale devices rather than large-scale turbines is a topic that has gained lots of interest. In this study, a compact device is proposed to harvest wind energy and transform it into electrical energy, by means of oscillations of a magnet into a coil, using the concept of vortex-induced vibration (VIV) behind a barrier. For a more comprehensive investigation, this system is studied from two viewpoints of fluid mechanics (without magnet) and power generation (with the magnet). For this purpose, an oscillating plate hinging on one side and three barriers with different geometrical shapes including cylindrical, triangular and rectangular barriers are used. In addition to the effect of barrier geometry, the impacts of various barriers dimensions, the distance between the plate and the barriers as well as inclination angle of the plate with respect to the horizon on the amplitude of oscillations and generated power are investigated. Results showed that in each case, there is a unique Reynolds number in which the frequency of vortex shedding equals to the frequency of plate oscillation and the output power from the energy harvester device is maximum. Besides, by increasing the barrier dimensions, the amplitude of oscillations increases up to three times, which leads to a higher generated power. Finally, by considering the studied parameters, the best conditions for generating energy using the VIV method are presented for design purposes. Among all the considered cases, the cylindrical barrier with the highest diameter and nearest distance to the plate led to the highest efficiency (0.21%) in comparison with other barriers.

中文翻译：

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新型利用涡激振动收集能量的小型装置的实验研究

摘要

可再生能源可以很好地解决与化石燃料有关的问题。通过小型设备而不是大型涡轮机存储风能是一个引起人们极大兴趣的话题。在这项研究中，提出了一种紧凑的设备，它利用障碍物后面的涡激振动（VIV）的概念，通过将磁体振荡成线圈来收集风能并将其转化为电能。为了进行更全面的研究，从流体力学（无磁体）和发电（有磁体）两个角度研究了该系统。为此，使用在一侧铰接的振动板和具有不同几何形状的三个屏障，包括圆柱形，三角形和矩形屏障。除了障碍几何形状的影响之外，研究了各种障碍物尺寸，板与障碍物之间的距离以及板相对于地平线的倾斜角度对振荡幅度和产生功率的影响。结果表明，在每种情况下，都有一个唯一的雷诺数，其中涡旋脱落的频率等于极板振荡的频率，并且能量收集器设备的输出功率最大。此外，通过增加势垒尺寸，振荡的幅度增加到三倍，这导致更高的产生功率。最后，通过考虑所研究的参数，提出了使用VIV方法产生能量的最佳条件，以用于设计目的。在所有考虑的案例中，