臺灣大學: 機械工程學研究所楊馥菱葉啟安Yeh, Chi-AnChi-AnYeh2013-04-012018-06-282013-04-012018-06-282010http://ntur.lib.ntu.edu.tw//handle/246246/256202　　有鑑於非穩態流體力之研究所需，一專事於量測非穩態流體力之實驗平台已順利在實驗室規模之下落成。其架構包含三個主要部分：感測元件，運動控制系統，以及資料擷取系統。同步控制之下使非穩態流體力進行即時量測之目的已具體達成。採用的感測元件中，其一應用傳統應變規量測表面剪應力，其二則使用換能器專事壓力量測。 　　針對兩種換能器，皆根據各種精確控制下的流體運動，以進行非穩態校正。對流體剪應力量測元件所進行的穩態與準穩態測試，為分別採用圓形Couette流場以及與Stokes第二問題相同的振盪流場。理論分析也同時在分析實驗現象中一併導入。而最終的分析結果顯示該感測元件對流體運動之反應，表現於於黏滯剪應力之效應以及和流場的熱交換中。 　　對壓力感測元件所進行的測試中，採用了垂直方向的簡諧振盪運動以檢視其非穩態反應。同時提出了根據瞬時速度和加速度預測動態壓力之關係式，並與實際量測而得之動態壓力進行比較。最後根據預測結果與量測結果之誤差，以系統化的方式進行了定量分析。This research aims to develop an apparatus to achieve in-situ measurement of unsteady hydro-dynamic forces. The current facility has been built by integrating sensing modules, a motion control system and a data acquisition system. Two types of sensing modules have been developed using conventional strain gages for shear stress measurement and transducers for pressure measurement individually. Extensive efforts were made to calibrate the sensing modules using well-controlled fluid mo-tions. For shear stress sensing modules, steady and quasi-steady test were performed using a rota-tional Couette flow and an oscillating flow as described in the Stokes second problem. Theoretical analysis has also been conducted to examine the experimental findings. It was found that the sens-ing module for shear stress measurement responds to both the viscous stress and the thermal inter-actions with the flow. For pressure sensing modules, a quasi-steady test was performed using a vertical oscillation. Based on the proposed working formula, we gave predictions to the instantaneous dynamic pressure and compared it with the actual measurements.3799531 bytesapplication/pdfen-US非穩態流體力即時量測應變規感測器震盪流場in-situ measurementunsteady hydrodynamic forcestrain gagetransduceroscillation flowthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/256202/1/ntu-99-R97522120-1.pdf