本研究利用可撓式MEMS熱膜感測器進行鈍形體渦流溢放過程尾流三維特性與非定常特徵之量測，並達到不破壞流場為基礎來探討此複雜的三維非定常流場物理現象。實驗以可撓式熱膜感測器陣列黏貼在梯型鈍形體表面於雷諾數範圍24600至42000進行量測，進而得到瞬時多點位置之瞬時流場訊號，研究並使用小波轉換分析求得渦流溢放訊號之振幅A(t)、渦流溢放瞬時頻率f(t)與側向相位差變化，以探討渦流結構三維性與低頻擾動現象。
　　實驗結果顯示，渦流溢放訊號低頻擾動與渦流溢放瞬時頻率有明顯的相關性，梯型鈍形A(t)與f(t)之相關性係數為-0.4，梯型鈍形體附加延長平板A(t)與f(t)之相關性係數可達-0.7。流場三維性方面，梯型鈍形體之渦流溢放側向相位差最大值可達56度，梯型鈍形體附加延長平板之最大相位差值約為28度。整體而言，梯型鈍形體附加延長平板之渦流溢放流場具有較佳的規律性與二維特性。

　　Self-made MEMS thermal film sensors were employed to investigate the three-dimensional, unsteady characteristics of a separated shear layer, originated from a bluff body. Thus, three-dimensional characteristics of vortex shedding could be studied with the MEMS sensors without disturbing the flow. In this study, two bluff bodies were employed, one of which was a normal plate and the other was a normal plate with the splitter. In the wind tunnel at Re=24600 to 42000, the sensors were arranged along the spanwise direction, on the frontal face of the normal plate, in order to gather the information of flow at multiple points simultaneously. In processing the data, a technique of Wavelet transformation was employed to obtain the instantaneous information of amplitude, frequency, and phase of fluctuations with respect to the vortex shedding frequency component. Subsequently, the linkage between three-dimensional characteristics of vortex shedding and low- frequency unsteadiness was examined.
　　Results show that the variations of instantaneous vortex shedding frequency and low-frequency modulations appear to be correlated in a negative manner. The cross-correlation coefficients in the normal plate case reach -0.4 in value and the cross-correlation coefficients of the normal plate with the splitter can reach -0.7 in value. Concerning the three-dimensionality of vortex shedding, the spanwise phase difference value of vortex shedding of the normal plate can reach as high as 56 in degrees; and the spanwise phase difference value of vortex shedding of the normal plate with the splitter is 28 in degrees. To sum up, the vortex shedding of the normal plate with the splitter is more regular and two-dimensional than that without the splitter.

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