本文分為兩大主題。在第一個主題中，利用點火與相機觸發時點之時間延遲量輔以局部高速攝影成功首次解析兩透明平板所構成之260 μm 間隙內，乙烯/氧氣反應波由中心引燃往外環狀擴張直至產生爆震焰之動態。反應波發展初期距離點火0 μs 至60 μs，此時火焰以平滑對稱之環狀進行擴張。當距點火60至130 μs，受到火焰不穩定性影響，火焰表面形成許多褶皺之花瓣狀環狀反應波前，同時壁面黏滯效應而受到阻滯，致使壓力提升。在點火後135 μs 時，可以發現在火焰面前端隨機位置產生了局部爆炸，反應波隨即由緩燃焰(deflagration)轉變為爆震焰(detonation) 傳遞，透過高解析度顯影於反應波前所觀察到之細胞結構即驗證了爆震焰之產生。此外與120 μm 微間隙結果比較可知，DDT半徑與間隙大小成正相關。
在第二個主題中，利用高速攝影、碳膜顯影(soot film visualization)方式探討乙烯/氧氣爆震焰在增加氮氣稀釋或改變當量比條件下，通過突擴時之速度變化、傳遞模式及重新引燃機制。研究發現隨著燃氣比例的改變，爆震焰可以兩種爆震焰模態傳遞通過微槽突擴。第一類為在氮氣稀釋β=0.2以下或當量比Φ=0.7以上時，爆震焰在通過突擴時減速，但於寬槽傳遞40 mm內之距離內又重新加速為C-J爆震焰。經由碳膜顯影輔以觀察可知，在此模式下爆震焰之重新引燃機制是由於震波反射之三相點壓縮點火所致。第二類為氮氣稀釋β=0.3至0.6或當量比Φ=0.6至0.5，爆震焰在通過突擴減速後，需再經前類3-4倍距離始能再加速至近C-J速度。此模式由碳膜顯影觀察知此時重新引燃機制為寬槽內壓力累積所產生的DDT過程。最後當氮氣稀釋繼續增加或當量比繼續往貧油方向減少，則可在窄槽內觀察到兩種緩燃焰傳遞模式。

Two subjects were included in this research. In first part, we analyzed a circular propagating reaction wave of stoichiometric ethylene/oxygen mixtures in a 260μm gap. To analyze the transmission of circular reaction wave in micro gap, full frame image of the flame at different instants were taken by adjusting the time delay between ignition and camera trigger timing. High speed cinematography on a strip region encompassing the plate center was also performed to quantify the expanding rate of the circular flame. The result shows two stages of flame acceleration. In first stage, the flame became wrinkled soon after ignition due to the instabilities, further acceleration due to the choking effect of the micro gap in the unburned gas region was observed in the later stage. Local explosions in the flame front due to the pressure accumulation were clearly visualized at 135 μs after ignition and cell structures were observed in the detonation fronts. We also compared the result to a 120 μm gap, it shows DDT radius has positive correlation with gap size.

In second part, detonation wave transmission across a sudden expansion in a millimeter-scale channel was experimentally studied using high speed cinematography and soot film visualization. The effect of nitrogen concentration in stoichiometric ethylene/oxygen enriched air mixture (dilution ratio, β) and fuel lean ethylene/oxygen (equivalence ratio, Φ) on the variation of detonation wave propagation velocity was investigated. Two propagation modes were characterized based on the velocity evolutions of the reaction front. For mixtures with β less than 0.2 or Φ larger than 0.7, detonation wave decelerated as it propagated across the sudden expansion and re-accelerated to a near C-J velocity, slightly higher than that in the narrow channel within 40 mm. From the soot film visualization, we found the detonation re-initiation mechanism in wider channel is owing to shock reflection. And detonation wave tooks a distance 3-4 times longer to re-accelerate to a near C-J velocity after it traveled across the sudden expansion, while β is between 0.3-0.6 or Φ between 0.5-0.6. And the re-initiation mechanism is onset by DDT.

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