在超音速燃燒衝壓引擎中，由於燃料停留在流場的時間極為短暫，因此需在流場中設立駐焰機制。本論文選擇以凹槽(長深比為3)作為研究之駐焰機構，以減少全壓損失。實驗觀察使用歸仁校區之自行設計之高焓（全溫逾630K）2馬赫連管風洞，將JP4於凹槽前壁面開孔(Φ0.5mm)注入，並以具自燃性的過氧化氫/煤油基燃料噴注器作為點火機構；此機構具簡單、安全及穩定等特性。
冷流實驗觀察結果顯示JP4噴注角度影響其進入凹槽迴流之比例；本研究固定噴注角度為0°(水平噴注)進行燃燒實驗。點火實驗結果顯示，當JP4噴注流量約4.5g/sec時，凹槽內燃氣比達可燃範圍，點火器開啟預熱槽燃氣至後緣斜壁面溫1200K以上，可成功駐焰，且透過自然螢光觀測到燃燒之高溫處在凹槽斜壁面。但由於系統流量調控不夠穩定，使得每組成功駐焰的實驗尚未達到合宜之重複性，需整置系統後實驗確認駐焰條件。

In scramjet engine, the fuel stays in the flow field for a very short time, it is necessary to set up a flame holding mechanism in the flow field. In this paper, the cavity (length-to-depth ratio is 3) is chosen as the flame holding mechanism to reduce the total pressure loss. The experiment uses the self-designed high enthalpy Mach 2 connected-pipe wind tunnel on the Qui Nhon campus. JP4 is injected into the frontwall of the cavity (Φ0.5mm) and choose the self-ignitable hydrogen peroxide/kerosene-based fuel as an ignition mechanism; this mechanism is simple, safe and stable.
The observation results of the cold flow experiment show that the injection angle of JP4 affects of its proportion into the cavity. In this study, the injection angle is chosen at 0°(horizontal injection) for the combustion experiment. The results of the ignition experiment show that when the airflow for total temperature is above 630K and the igniter heat the fuel that the air gas temperature which the thermocouple measured on the backwall of the cavity trailing edge is above about 1200K, the flame can be successfully maintained, and chemiluminescence show high temperature is at the backwall of cavity. However, the flow control system is not stable enough, the experiment of each group of successful flame retention has not reached the appropriate repeatability yet.

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