摘要 在近代的醫學工程技術中出現了一項新技術 – 組織工程，組織工程是希望在體外培養出適合的組織或細胞，去修補體內受傷部份以維持身體的正常機能。生物反應器為組織工程提供ㄧ培養環境，供學者及醫療人員在體外培養細胞，其中ㄧ種為圓錐平板型生物反應器可同時提供層流及紊流形式剪切環境，可用於模擬血液流動對於血管內皮細胞所造成之剪切力，因此我們希望了解當細胞培養於圓錐平板裝置平板表面時，所承受之剪應力大小，以提供學者或是醫療人員在培養細胞時ㄧ個參考。在本文中我們架構出ㄧ圓錐平板裝置，控制馬達以週期式轉速運轉，希望以實驗之方式了解改變雷諾數、轉數比以及轉速變動頻率對平板上剪應力之影響，並與先前學者研究結果相比較，了解其理論估算公式之適用性。在實驗結果中發現當轉速比越高時，二次流場及紊流流場之效應會越大，當轉速變動頻率越大時，由於慣性力的關係，流體速度無法緊跟著圓錐轉速變動而變動，將使平板上剪應力降低。 Abstract Tissue engineering as an emerging biomedical technology is tempted to cultivate tissues or cells in vitro so as to repair the damaged parts of organ and maintain the normal function of body. The tissues and cells are cultivated in an in vitro device called the bioreactor. Bioreactors provide proper culturing environments to the cultivated cells. Cone-and-plate apparatus has been used as a bioreactor to provide the shear stresses from laminar to turbulent flow, which may simulate the shear stresses encountered by the endothelial cells in the arterial circulation. We design a cone-and-plate device to help us understand the shear stresses exertion in such a geometric region. In our experiment, we change both the rotation speed and rotation frequency to understand the effects of the shear stress on the plate, and compare our results with the early research. We find that when the rotation speed is large, both the effects of secondary flow and turbulent flow will be enhanced. When the rotation frequency become large, the shear stress on the plate will be decreased due to the action of the unsteady inertia.
