樞軸式噴注器(pintle injector)由於構造簡單，且無燃燒不穩定性，故已被廣泛使用在太空任務上。傳統上樞軸式噴注器為一股推進劑流經內管以徑向噴注，而另一股推進劑則是以環狀的薄膜軸向噴出，樞軸式噴注器常常利用多孔或是雙排多孔來增加徑向噴流與軸向噴流的撞擊，但在高O/F ratio時，可能會有部分軸向噴流無法被徑向噴流帶離噴注器的問題，故本研究在樞軸式噴注器上加上溝槽，以限制軸向噴流的流動，使得軸向噴流與徑向噴流有較完整的撞擊。
本研究的目的，是研究自行設計的樞軸式噴注器之流量使用限制，並利用PLIF(Planar Laser–Induced Fluorescence)技術，取得二維質量機率分布圖與混合比圖，進行噴注的觀察實驗分析，實驗結果顯示，適當的溝槽寬度與徑向噴孔孔徑之比值(W/D≈1.5)，對於樞軸噴注器噴注器的流量限制範圍與兩噴流混合上有相當的幫助，且動量比是主要影響噴注的混合、質量分布等特性的重要參數。

Pintle type injector has been widely used in space mission because it is easier to design and it leads to more stable combustion. The conventional pintle injector design creates mixing between radial flow and axial flow of propellants from orifices and on surface of a closed end tube, respectively. Single- or multi-row of orifices for the radial flows are common used in the design to make sure proper impingement between propellants. However, it is difficult to have complete impingement at high propellant flow rate ratio conditions that some of the axial flow propellant may bypass the radial jets. This research focuses on the design of a pintle injector with channels to restrict the axial flow and expect a more efficient mixing of propellants. PLIF technique is utilized in this study to observe the mass distribution and mixing ratio with different design parameters. The results show that appropriate channel width helps the liquid mass distributed more uniform and have more efficient mixing. In this study, the channel width is suggested to be 1.5 times of orifice diameter. As momentum flux ratio is increased, the mass distribution becomes more uniform as well as mixing ratio.

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