磁電及流固耦合參數激擾之能量擷取系統分析

自然界的振動現象無所不在，因此利用振動來發電的振動能量擷取器是一個十分熱門的領域。傳統能量擷取系統大多是將壓電片放置於彈性結構體根部，藉由其受力及形變產生電能轉換。若要以此法獲取較大的電能，勢必要加長壓電片的長度，意謂必須承擔壓電片破損的代價。本研究提出一改良創新的設計，除了利用流體產生的激擾，帶動管道振動，以此流固耦合的振動產生電能;另外，再以流體本身的能量帶動管道內的旋轉水車驅動管道外的連桿，並連接至壓電片處，帶動裝設磁鐵之旋轉裝置，以磁鐵的斥力同時激擾壓電片，達到更佳的發電效益。此裝置不但能獲取傳統獵能系統的電能，還能額外獲得壓電片(PZT)受到磁鐵的斥力之電能，完美的使其發電效益能達到最大程度的利用與發揮。本研究除了以理論及實驗相互驗證此流體-磁-電及參數激擾之能量擷取裝置的可行性，及壓電片裝設的位置; 並考慮流力與管道造成的耦合影響，加入兩者的互動參數於此彈性結構。此外，因為顧及磁鐵的斥力及結構體的彈性產生較大之形變，在理論模擬時將以非線性振動樑的理論模擬兩端固定(Fixed-Fixed)的長條彈性管道之振動，並與壓電及磁電方程式耦合，分析此系統理論電能轉換之電壓及功率，與實驗驗證並修正理論模式，以求得更廣泛的應用。本研究係考慮一流體輸送非線性彈性樑 (Fluid-Conveying Nonlinear Beam) 為主體模型，除此之外，非線性彈性樑為兩端皆固定和有流體之流場影響，故此在本研究中有探討拉伸效應 (Stretching Effect) 和流固耦合之效應 (Fluid-Structure Interaction)，並且探討其流場所產生之參數激擾影響並繪製出系統因外力大小和頻率不同造成的不穩定範圍;吾人藉助以多尺度法 (Method Of Multiple Scales, MOMS)、定點圖 (Fix point plot)、時間響應圖 (Time response plot)、相位圖 (Phase plot)和龐加萊映射 (Poincaré Map) 來驗證其繪圖之正確性。吾人更進一步在系統中放入壓電片來達到發電效果，利用 PZT的發電量來驗證吾人計算之不穩定範圍之正確性。此外吾人將流固耦合之方程式中放入壓電方程以及根據磁鐵間的斥力所造成的磁場效應，以此來增加實驗之發電效應。

關鍵字

非線性振動；參數激擾；獵能；多尺度法

並列摘要

The development of green energy technology has been the trend in recent years. The research on vibration energy harvesters that use vibration to generate electricity is a very popular field. Most traditional energy harvesting systems place a piezoelectric patch (PZT) on the root of an elastic structure, and generate electrical energy conversion through its deformation. In order to obtain larger electric energy, it is necessary to increase the length of the piezoelectric sheet, which means that the piezoelectric patch might be damaged or paid a very high cost. This research proposes an improved and innovative design. In addition to using the turbulence generated by the fluid to drive the pipeline to vibrate, the fluid-solid coupling vibration generates electricity, and the fluid's own energy drives the rotating device in the pipeline to drive the connecting rod. Stimulate the piezoelectric patch to achieve better power generation efficiency. This device can not only obtain the electric energy of the traditional energy harvesting system, but also obtain the electric energy of the repulsive force on the PZT by the magnet, so that the power generation efficiency can be used and exerted to the greatest extent. In addition, because the repulsive force of the magnet and the elasticity of the structure produce large deformations, the theoretical model of the nonlinear vibrating beam will be used to simulate the vibration of the fixed-fixed long elastic pipe during the theoretical simulation, and it will be coupled with the piezoelectric and magneto-electric equations. Analyze the voltage and power of the theoretical electric energy conversion of this system, verify the theoretical model with experiments, in order to obtain a wider range of applications.

並列關鍵字

Nonlinear vibration ； parametric excitation ； energy harvesting ； MOMS

參考文獻

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