流致振动发电组合截面振子及阵列驰振诱发机制研究

The emerging Flow-induced Motion Energy Conversion (FIMEC) has attracted increasing attention in Marine Hydrokinetic (MHK) field. With the development of the research, it has been found that the vibration of non-circular oscillators can be excited to galloping at high flow velocity. The vibration intensity is enhanced, and the energy harness efficiency and utilization range are both improved. The galloping of non-circular oscillators contains Soft Galloping (SG) and Hard Galloping (HG) at different conditions. When HG occurs, the oscillator cannot be self-excited by Vortex-induced Vibration (VIV) to galloping, resulting in an energy waste of galloping. The lack of study in mechanism of galloping for the non-circular oscillators impacts the further development of FIMEC. In order to improve the energy conversion capacity, the "circular-prism" combined oscillators, as well as the multi-oscillator arrays are investigated through physical model tests, theoretical and numerical approaches in this study. The Flow-induced Motion and energy conversion experiments of single-oscillator with variable cross-sections, array-oscillators with different spacing and single-oscillator with variable excitations of generator are conducted to investigate the induction mechanism and characteristics of the galloping, and to obtain the optimal cross section, layout of oscillators, and excitation adjustment method. The research content can guide the design and operation of the FIMEC device, which has a certain engineering value.

新兴的流致振动发电已成为海流能利用的研究热点。随着研究的深入，人们发现非圆截面振子可在高流速下发生驰振，振动强度提升，能量利用效率与范围也有所提升。但该类振子的驰振表现出软、硬两种形态，当发生硬驰振时，振子不可由涡激振动自激励诱发驰振，导致驰振能量无法利用，造成能量浪费。非圆截面振子驰振的诱发条件与机理等研究内容的欠缺，影响了流致振动发电技术的进一步发展。为此，本项目以提高流致振动发电能力为前提，采用物理模型实验、理论研究、数值分析等方法，对“圆柱-棱柱”组合振子及其阵列进行研究。通过开展单振子变截面、双振子串并列及变发电机励磁条件下的流致振动实验，揭示驰振的诱发机制与诱发条件，并确定发电最优的组合截面与空间阵列方式，提出合理的发电机励磁调节方法。研究内容可指导流致振动发电装置的设计与运行，具有一定工程价值。

流致振动发电作为新兴海流能利用理念已成为海洋工程的研究热点，非圆截面振子硬驰振时，振子不可自激励诱发驰振，能量利用受限。本项目以提高流致振动发电能力为出发点，采用理论与试验结合方式进行三棱柱及“圆-棱-附板”组合截面振子及其阵列条件下的流致振动、能量利用、尾流结构等研究。基于流致振动发电与尾流测试系统，进行了系统试验研究，掌握了尾流结构与诱发条件，揭示了振动诱发机制，明确了最优截面；进行了双三棱柱串、并、错列下的振动及发电试验，获得了多振子相干条件下的尾流结构，阐明了间距对振动及能量利用的影响，揭示了相干机制，提出了最优阵列布局；基于硬驰振特点，项目开发了变励磁发电调控装置，提出并验证了高流速驰振能量利用调控策略；首次提出并初步探索了偶联串列双圆柱流致摆振特性，建立并验证了理论模型，基于试验结果分析了间距对摆振的影响规律。研究内容旨在为流致振动发电装置的设计与运行提供参考，具有一定工程价值。