雙方向渦流誘發振動能量採集器之設計與分析

Design and Analysis of a Bi-directional Vortex-induced Vibration Energy Harvester

林文宇(Wun-Yu Lin)

指導教授 ： 蘇偉儁

國立臺灣大學/工學院/機械工程學研究所/碩士(2019年)

https://doi.org/10.6342/NTU201901496

摘要

利用風力做為振動源的壓電能量採集器近年來受到許多的研究，但主要皆是以壓電懸臂樑做為採集器結構，因此只能進行單一風速方向的採集。本研究在此利用框形樑結構，結合圓柱體結構設計一雙方向壓電能量採集器，此採集器結構可採集兩個方向的風速，且兩個風速之間互相正交，藉由圓柱體受風後產生的渦流誘發振動現象，即可做為採集器的振動源。本研究在理論模型上的建立是以古典樑力學和壓電本構方程式為基礎，搭配渦流升力模型，推導出系統在受渦流誘發振動下的力電偶合方程式，並以數值解來模擬系統的動態響應，接著透過與實驗結果的相互對照，調整渦流升力模型中的擬合係數來使模擬結果貼近實驗結果。此外，本研究將會進行參數化分析，調整採集器的寬高比配置以及使用不同的圓柱體直徑，比較各項參數改變後的效果，以所推導的理論模型來嘗試重現採集器在渦流誘發振動下的動態響應。整體而言，本研究所設計的採集器具有兩個風速方向的採集能力，且能採集的風速範圍和採集電壓會隨著圓柱體直徑的增加而變大，但同時也會更容易產生結構上非預期的變形。若透過調整合適的寬高比和圓柱體直徑，即可在不使採集器結構產生非預期的變形下得到更好的採集效果。

關鍵字

壓電能量採集器 ； 渦流誘發振動 ； 雙方向

並列摘要

Piezoelectric energy harvesters using wind as a vibration source have received a lot of research in recent years, but mainly use cantilever beams as the structure, so the energy can only be captured at single wind speed direction. In this thesis, a frame-shaped beam is combined with a cylinder to designed a Bi-directional energy harvester, which can capture energy in two orthogonal wind speed directions that using a phenomenon called vortex-induced vibration as the vibration source. As for the theoretical model of this thesis, the governing equations of the coupling system are derived from conventional beam theory and piezoelectric constitutive equation and lift oscillator model. The dynamic response of the coupling system is solved by numerical method, adjusting the fitting parameters of the lift oscillator model to let the simulation results closer to experimental result. In addition, this study will perform parametric analysis, such as adjust the aspect ratio of the structure and use different cylinder diameters and then try to reproduce the dynamic response with theoretical model. Overall, the harvester designed in this study can harvest wind energy in both directional, and the wind speed range and acquisition voltage will both increase as the diameter of the cylinder increase, but at the same time it will easier to suffered from unexpected deformation. By adjusting the appropriate aspect ratio of the structure and the diameter of the cylinder, better acquisition results can be achieved without unexpected deformation of the harvester structure.

並列關鍵字

Piezoelectric energy harvester ； Vortex-induced vibration ； Bi-directional

參考文獻

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