中文摘要
題目:不同呼吸循環下健康及氣喘患者呼吸道內空氣與PM2.5之數值研究
研究生:楊哲維
指導教授:黃啟鐘
近年來，常聽聞台灣部分地區之空氣品質不佳甚至已達PM2.5濃度的警戒範圍，等同於紫爆濃度等級，而這些細懸浮微粒(particulate matter)通常附隨有毒物質經由呼吸系統進入人體囤積，進而造成健康的危害，為當今須關注重要議題之一，故此，本文從中探討PM2.5對於人體器官內的行為，並透過理論探討與數值模擬之研究方式。
經由相關理論驗證後，在數值模擬部分，本文參照其中之相關參數設定，以商用軟體ANSYS FLUENT來計算氣相空氣與固相粒子之三維不可壓縮暫態流，首先利用繪圖軟體CATIA建立健康及氣喘患者呼吸道模型，接著匯入ANSYS Meshing內來建構網格，最後再將網格導入FLUENT，利用正弦波模擬休息、輕微活動和適度運動呼吸循環時，其雷諾數與時間的關係以計算流場，並在入口處放入固態粒子，以使用者自訂函數(User Define Function，簡稱UDF)初始化固態粒子之初始條件後，進而求解雙向耦合之兩相暫態流。
以上，經本文模擬結果如下：(一) 在健康分歧管中，顆粒總沉積率極低；(二) 在氣喘分歧管中，迪恩渦流及二次流動皆與健康分歧管來的劇烈；(三) 在空氣中，顆粒粒徑越小囤積於人體體內之量也越高；(四)呼吸循環下，吸氣時之沉積量遠大於呼氣時之沉積量；(五) 氣喘呼吸道的呼吸循環效率略低於健康呼吸道。
此外，本文除了探討不同氣管模型和呼吸循環下顆粒之沉積分率，亦對於沉積位置及流場現象的可視化著墨，期望提供未來在PM2.5相關研究資料以及於健康風險評估方面提供幫助。

關鍵字: PM2.5、暫態流、兩相流、呼吸循環、顆粒沉積

The impacts of ambient PM2.5 on public health have become a concern in Taiwan and other parts of the world. Epidemiological and toxicological studies have shown that PM2.5 does not only induce cardiopulmonary disorders and impairments, but also contributes to a variety of other adverse health effects, such as driving the initiation and progression of diabetes mellitus and electing adverse birth outcomes. In this study, the ANSYS commercial code, comprehensive three-dimensional numerical model was introduced to study the gas-solid two-way flow behaviors in healthy and asthmatic airway. Three generations bifurcation models of respiratory G10-G12. Three realistic breathing patterns, i.e., rest condition, light activity and moderate exercise, were considered. Two different concentrations were used i.e., 30μg/m3 and 80μg/m3. The transient gas phase was modeled with laminar incompressible flow and the particle phase was captured by discrete phase model (DPM). Where air velocity was stronger, a more skewed phenomenon was observed during inhalation, and air velocity had two peak vectors combine to form one big vector in the next generation during exhalation. Moreover , the breathing in healthy airway more effective compared to asthmatic airway. A large amount of PM2.5 is not retained by the airways and can transit to the alveolar region. Thus, people with asthma have a higher total respiratory dose of PM2.5 for a given exposure, which may contribute to their increased susceptibility to the health effects of air pollution.

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