微圓管內空氣流實驗研究

Experimental Study of Air Flow in Microtubes

陳育堂(Yu-Tang Chen) ； 康尚文(Sheng-Hong Tsai) ； 謝宏榮(Hung-Jung Shei)

《中華科技大學學報》 69期 (2017/01) Pp. 45-56

摘要

本研究主要是以空氣為工作流體，研究探討空氣在微圓管中之流力性質，利用兩種不同尺寸之玻璃微圓管進行實驗分析與討論，其水力直徑分別為287μm和409μm。並利用光學顯微鏡及影像處理技術分析得到玻璃微圓管的真圓度偏差皆在2%～4%；以表面形貌儀（KLA-Tencor α step-500）測得微圓管內部之表面平均粗糙度皆低於15 nm，得以作為流力分析之重要參考依據。考量工作流體具壓縮性質，故實驗結果顯示，無論是層流區域或紊流區，皆可以Fanno-line flow機制分析，所得之平均摩擦因子大致皆可與Poiseuille（f = 64/Re）和Blasius equations（f = 0.316/Re^(0.25)）吻合；並可顯現出研究成果之連貫性與一致性。

關鍵字

玻璃微圓管 ； 真圓度 ； 粗糙度 ； 壓縮流體 ； Fanno-line flow機制 ； 平均摩擦因子

並列摘要

Airflow through microtubes with diameters of 287 to 409 μm was investigated experimentally and analyzed by Fanno-line flow. Using precise image-processing analysis, the investigated glass microtubes were found to have a roundness deviation of 4%. Using the Alpha-step profiler, the average microtube inner wall surface roughness was obtained below 15 nm. The pressure drop and flow rates were measured to analyze the flow characteristics. The experimental results indicate that friction factor f obtained from Fanno-line flow shows good conformity with Poiseuille (f = 64/Re) and Blasius equations (f = 0.316/Re^(0.25)) in both laminar and turbulent flow. These results illustrate continuity and coherence in this research.

並列關鍵字

Microtubes ； Image-processing analysis ； Roundness deviation ； Surface roughness ； Fanno-line flow function