摘要随着全球经济的发展，对能源的需求越来越大，急需寻找可再生能源，替代地球上有限的不可再生能源，以解决能源危机。而海流中蕴藏着丰富的可再生能源，如果这些能源能够被捕获和利用，将会改善不可再生能源日趋枯竭的现状。涡激振动发电装置是通过利用涡激振动效应，捕获海流能的设备，是一种在较低流速条件下的低成本海流能发电方式，该技术的应用成为了当今世界学者们的研究热点。本文主要研究单柱体在海流能捕获能量效率方面的分析，包括理论分析与数值模拟分析，在数值模拟中，本文分别对不同截面形状和不同参数两个影响方面进行研究。

本文首先对涡激振动捕获海流能原理进行了理论分析，利用数学方程、能量转化模型，整理出相关的关键参数，建立了获能效率的方程；在数值模拟方面，本文确定了“频锁”范围，选择合适的流速后，计算得出振幅、频率等相关参数，并且结合第二章所建立的方程，将计算结果进行处理。78142

以上为本文主要研究内容的概述，本文的结论包括以下几个方面：

（1）对单柱体涡激振动捕获能量进行双自由度分析，通过建立的数学模型和公式，本文推导得到了获能效率公式。

（2）使用ANSYS软件，在流速下，通过数值模拟得到单柱体在不同截面形式下的响应情况，分析发现梯形的涡激振动十分不规则，正方形截面形式柱体比圆形、梯形、三角形这三种截面形式下柱体的最大升力和最大拖曳力大；并且得到了各个截面形式下的尾涡模式。

（3）利用第二章的获能效率公式，并把数值模拟得到的数据代入比较，发现捕获效率在约化速度、阻尼比系数下最大。

毕业论文关键词：涡激振动；捕获能量；效率；不同截面形状；阻尼比；单柱体

Abstract With the development of the global economy, there is an increasing need of energy resources。 It is urgent to find out renewable energy  taking  place of  non-renewable energy limited on earth, to solve the crisis of energy。 If the energy abundant in the ocean currents can be harvested and used, the rapid depletion of  non-renewable energy will be alleviated。 The power generator based on vortex induced vibration (VIV) harvests ocean energy, even at very low speed , without high cost。 The application of energy-harvesting technique has been the research focus of  scholars in the contemporary world。 In the present work, the main contents are centered on the efficiency analysis of harvesting energy for single cylinder, including theoretical analysis and the numerical simulation。 Especially during the numerical simulation of single cylinder with different cross sections and with different damping ratios, we carry out the research on both of them。

In the present work, we begin theoretically analysing the principle of harvesting energy with VIV。 After investigating on mathematical equation and the model of energy conversion, we attain some key parameters and establish efficiency equation; with numerical simulation, the range of “lock-in” has been obtained。 According to the range, we select the appropriate flow speed。 The related parameters can be obtained, and the results will be discussed with the equation in the second chapter。

The above is the overview of main research contents。 The conclusion contains the following aspects:

(1)With two-degree-freedom analysis of single-cylinder VIV, the efficiency equation of harvesting energy can be obtained based on established mathematical models and equations。

(2)Using ANSYS, the single-cylinder responses of different cross sections have been obtained with numerical simulation when flow speed is 0。3m/s。 It appears that VIV of trapezoid is much irregular; the maximums of lift force and drag force of square are bigger than of circular,trapezoid and triangle; the different patterns of wake of different cross sections also can be obtained。