本論文以物理性質與NTO 及MMH 相似之模擬溶液研究異質衝擊霧化現象。擷取噴霧的正面及側面影像與應用PLIF 技術觀察霧化錐體之截面影像，並輔以簡易的統計分析定義衝擊噴流的二維質量機率分佈。為符合五磅級雙基推進劑之液態火箭推進器（NTO/MMH）之操作參數，故實驗噴流總流量固定為7.96g/s，噴注器孔口直徑為0.3mm，衝擊角為60°;異質噴流氧化劑對燃料質量流量比（O/F）為1.0〜1.6。分析實驗結果得以下結論：

(1) 假設衝擊噴流自衝擊點往下游之液滴質量分佈皆呈Weibull 函數分佈。利用相機於衝擊霧化區域相鄰兩側所取得之影像，成功地建立霧化液滴於特定截面的濃度分佈。然而此技術不適用於霧化錐體形狀呈凹型時，亦為衝擊噴流之動量比遠離1 時。

(2) 以分析平面雷射激發之散射光灰階影像的方法量測冷流場衝擊噴流霧化液滴的質量分佈。由此方法得知霧化液滴於空間中的分佈強烈地受到噴流動量比值影響。當動量比增大，霧化液滴的分布往噴流動量較弱的MMH 噴注器端偏移，而由分析霧化扇面的前視與側視影像亦可得此相同結論。

(3) 比較異質噴流與同質噴流之霧化液滴質量機率分布，顯示影響霧化液滴質量分布的因素，除噴流衝擊動量的比值外，噴流的物理性質亦會影響霧化液滴的質量分佈。

(4) 利用PLIF 技術監測單股噴流的質量分佈，不但可得知霧化液滴的混合比分佈，亦可於無限快的反應速度之假設下估算燃燒時之火焰溫度分佈。分析結果指出最高火焰溫度並未顯著地隨O/F 值改變。由目前的研究證實欲更完善地利用PLIF 技術觀測霧化現象，將需更高的雷射能量達到更精確地測定溫度與混合比的分佈。

　　This thesis studied the doublet impinging spray phenomena with fluids simulating the physical properties of NTO and MMH. Photographic images of front and side views as well as PLIF cross image of spray cone were observed. The two-dimensional probability distributions of the mass of impinging jets were determined by simple statistical analysis.The total mass flow rate was fixed as 7.96g/s to meet the operational condition of a 5-lbf MMH/NTO thruster. The orifice diameter of the injectors were 0.3mm and the impinging angle was set to be 60°. The experimental mass flow rate ratios of oxidizer to fuel (O/F) were varied between 1.0 and 1.6. Several conclusions were drawn from the observations:

(1) By assuming the downstream mass distribution of the impinging jets was self-preserved and modeled by Weibull distribution function, the planar mass distribution crossing the spray cone were　successfully determined from the photographs of the front- and side-view the spray fan. However,　this technique is inadequate when the shape of the spray cone was concaved, that is, the momentum ratio of the impinging jets is away from unity.

(2) Gray level analysis of the image from planar laser-induced light scattering observations were used to directly measure the mass distribution crossing the spray cone. It could be seen that the distribution was strongly affected by the ratio of jets’momenta. When the ratio of momenta increased, the distribution of spray moved toward the lower momentum injector, the same conclusion drawn from the analysis of the side-and front-view of the spray fan.

(3) To compare the observations of unlike-doublet to like-doublet impingements, it showed that the mass distribution of impinging jets were not only affected by the jet’s momentum ratio but also affected by the jet’s physical properties as well.

(4) PLIF technique was used to monitor the mass distribution of individual jet. The distributions of local mixture ratios as well as the estimated local temperatures were determined by assuming infinitely fast reaction. The results indicated that the peak flame temperature was not noticeably changed with O/F. The present study confirmed the adequacy of using PLIF technique in spray observation, more detailed determination of temperature and mixture ratio distributions required further studies with a higher energy pulse laser.

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