本文是以實驗的方式，來探討單一圓管浸在剪切水流場中的振動現象；在不同的參數下，圓管與流體間的振幅強度關係，主要以速度梯度的大小、圓管自然振動頻率及圓管中心速度的改變所發生的振動現象，將擷取到的數據經由頻譜分析以振動軌跡和振幅RMS，進而分析圓管在剪切流場誘發振動的原因。
由實驗結果得知，在圓管的自然頻率參數中以頻率愈高，其軌跡的表現愈趨於圓形形狀，且不會隨著實驗中的流速增加而在軌跡形狀有較大的改變，並不像在較低自然頻率如9Hz的時候，在X方向有較大的振幅發生。以X方向與Y方向的振幅之RMS值作為比較時，發現圓管自然頻率愈高，則X與Y方向的振幅之RMS大小相近，而這個現象在軌跡圖亦可明顯看到，圓管振動軌跡是趨近於圓形形狀的。隨著自然頻率降低，X與Y方向的振幅之RMS差異越大，軌跡圖所顯示出的振動軌跡是趨近於橢圓形狀。而流場所帶來的影響也會略為改變振動軌跡，最為明顯的是當圓管自然頻率為13HZ時且流場的速度梯度為0.514(1/sec)，會與流場發生共振現象。

The study aims to explore flow-induced vibration of shear flow past a circular cylinder. The major parameters in the experiment are the natural frequency of the cylinder, and the velocity and velocity gradient of the shear flow approaching the cylinder. The vibration of the cylinder in a water tunnel were measured by two accelerometers to simultaneously obtain the vibration amplitudes in both the streamwise and cross-stream directions.

The experimental results show that in the shear flow the cylinder tends of vibrate the orbits of the cylinder vibration become in the streamwise direction while in uniform flow the cylinder vibrates in all directions in the X-Y plane the tendency is obvious for the cylinder with high natural frequency (13Hz). The orbits of the cylinder with low natural frequency (9Hz) are basically similar in shear flow and in uniform flow.

中文摘要......................................................................................................I
英文摘要......................................................................................................II
目錄..............................................................................................................III
圖目錄..........................................................................................................V
符號說明..................................................................................................... X
第一章 緒論...............................................................................................1
1-1前言.......................................................................................................1
1-2文獻回顧..............................................................................................2
1-3研究動機..............................................................................................6
第二章 實驗設備與方法.........................................................................8
2-1實驗設備...............................................................................................8
2-2實驗儀器...............................................................................................9
2-3實驗方法.............................................................................................12
第三章 結果與討論.................................................................................14
3-1剪切流場的建立與量測..................................................................14
3-2不同自然頻率下之圓管振動.........................................................15
3-3剪切流與均勻流的振動軌跡比較................................................21
3-4不同圓管中心流速在X與Y方向的振幅RMS比較...............21
3-5 不同速度梯度的振幅RMS比較...................................................22

第四章 結論與建議................................................................................24
4-1結論........................................................................................................24
4-2建議........................................................................................................25
參考文獻.......................................................................................................26
附錄.................................................................................................................82

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