有限高圓柱為現代建築常出現之外觀，另一方面在競速比賽中人體不同部位也可以比擬成不同高寬比圓柱，均需要藉由探討受圓柱流場來深入了解所受影響。

本研究為探討非定常分離泡於臨界區之特性研究，吾一開始先以高寬比(Aspect ration)1、2、3、4之有限高圓柱進行油膜實驗，觀察其因雷諾數上升表面流場的變化，藉此了解流場對圓柱不同位置之影響，且進一步觀察不同高寬比圓柱流場三維性。

本實驗使用高寬比2圓柱模型來進行壓力量測，並使用間歇性係數此統計方法來量化兩側之間歇性現象搭配不對稱指標，分成四種狀態，判斷兩側隨著雷諾數增加，判斷其各狀態出現時間歇性因子變化，與出現單分離泡狀態時其非對稱於何側來判斷整個流場特性。

隨後並透過各種不同實驗的配合分析出三高層生成分離泡同步性與出現分離泡時不同角度壓力孔受影響是否存在相關性並使用頻譜分析來分析渦流溢放是否出現。

This research aims to study unsteadiness separation bubble around the finite cylinder at transition critical regime, First, oil-film visualization was used to observe the flow around the different aspect ratio (AR=1, 2, 3and 4) finite cylinders. The flow phenomenon observed could be categorized into three regions. Namely, there is the free end at the upper level of the model, the middle level where the flow can be regarded as passing over an uniform circular cylinder, and the lower level where the flow is constricted by the junction of the cylinder model, and along of the Reynold number increasing the cylinder surface flow field changing and can observe interesting phenomenon respectively the separation line and separation bubble switch each other at critical regime, two separation lines at low Reynold number, and can be observed finite circular cylinder flow field three-dimension because influence by tip vortex and induced vortex。

This research uses the intermittency factor and Asymmetric indicator to quantify the unsteadiness phenomenon in order to describe the two sides of separation bubble generate and when occur one-bubble state the separation bubble generate at which side, so we can clearly understand the separation bubble during one bubble state , on the other hand the oil-film result can further match our real-time pressure signals。

We analyzed the pressure using the fast Fourier transform to find the vortex shedding frequency in the experimental Reynold number regime and used correlation analysis gather additional data on factors influencing each pressure holes during separation bubble generation。

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