本文以實驗方式來探討金屬圓柱體在二維剪切流場中的運動行為。將一金屬弦線置於空氣噴流場中，空氣經過處理後產生線性剪切流場，剪切流層會使金屬弦線產生振動，加以磁場感應，可紀錄弦線振動的過程。用以建立剪切流場中金屬圓柱體振動的模型，可以觀察空氣剪切流場中圓柱的流體彈性振動之行為模式。藉此探討圓柱體在剪切流場所受到的流體不穩定的影響，並分析振動軌跡以期找出其中規律性。並針對不同圓柱與流體之間的質量比，圓柱的直徑，不同的衰減係數以及不同的速度梯度，對圓柱過臨界速度振動軌跡的影響。在實驗中圓柱的振動範圍受剪切流場影響而變化，振動軌跡大小隨速度梯度增加而變大，而衰減係數、質量比與張力的增加會使振動軌跡縮小或是振動不發生。

In the study, vibrations of small elastic cylinders mounted in the shear flow of an air jet are investigated experimentally. In such cases, the amplitude of the cylinder oscillation changed along with the variation of the jet velocity gradient is due to the influence of fluid elastic instability. The experiment is based on the method of the magnetic field induction to measure the motion of the small cylinder, and it involves measurements of the varying velocity in a jet through the hot- wire anemometer. We focus on the fluid-elastic instability of a circular cylinder in shear flow. The vibration behaviors of the cylinder above the critical condition are be examined with different velocity gradients, mass ratios and damping factors. The vibration amplitude of the cylinder is also larger as velocity gradient is larger. With lower mass ratios and damping factor, moreover, the orbit of cylinder is larger. When the velocity gradient is increasing, the frequency of cylinder vibration becomes higher.

中文摘要-------------------------------------------------------------------------- I
英文摘要--------------------------------------------------------------------------II
目錄 --------------------------------------------------------------------------III
圖目錄 --------------------------------------------------------------------------V
表目錄 ------------------------------------------------------------------------VII
符號說明-----------------------------------------------------------------------VIII

一、 前言-------------------------------------------------------------------------1
1-1. 文獻回顧---------------------------------------------------------------1
1-2. 研究動機與目的------------------------------------------------------5
二、 實驗設備儀器與方法----------------------------------------------------6
2-1. 實驗設備---------------------------------------------------------------6
2-2. 實驗儀器---------------------------------------------------------------7
2-3. 實驗方法---------------------------------------------------------------9
2-4. 實驗不準度-----------------------------------------------------------10
三、 結果與討論---------------------------------------------------------------11
3-1. 出口流場速度分布--------------------------------------------------12
3-2. 不同速度梯度的振動軌跡-----------------------------------------12
3-3. 不同衰減係數的振動軌跡-----------------------------------------13
3-4. 不同質量比的振動軌跡--------------------------------------------14
3-5. 張力與振動關係-----------------------------------------------------15
3-6. 速度梯度對振動關係-----------------------------------------------16
四、 結論與建議---------------------------------------------------------------17
五、 參考文獻------------------------------------------------------------------19
附錄------------------------------------------------------------------------44

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