Experimental Supersonic Hydrogen Combustion Employing Staged Injection Behind a Rearward-Facing Step
Experimental Supersonic Hydrogen Combustion Employing Staged Injection Behind a Rearward-Facing Step
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DOI：
10.2514/3.23646
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发表时间：
1993-06
影响因子：
1.9
通讯作者：
J. Abbitt;C. Segal;J. McDaniel;R. Krauss;R. Whitehurst
中科院分区：
文献类型：
--
作者：
J. Abbitt;C. Segal;J. McDaniel;R. Krauss;R. Whitehurst
为了研究超音速反应流场中的流动特性，对马赫数为2的燃烧室进行了实验研究。氢气被横向注入，作为分级的、未充分膨胀的射流，在向后的台阶后面进入有管道的2马赫自由气流。利用阴影照相法、宽带火焰发射照相法和平面激光诱导的氢氧化氢荧光技术研究了化学反应对超音速流场的影响。阴影图表明，放热对燃烧室内的波纹和流场的不稳定有很大的影响。宽频带火焰发射照片显示，燃料喷射器附近的大片区域没有燃烧，燃料/空气混合不足以支持燃烧。对于固定的氢气质量流量，随着自由流滞止温度的降低，这些区域的尺寸减小，这与燃烧时有效g比的增加是一致的。随着主流滞止温度的降低，平面荧光图像中含有羟基的区域尺寸也随之增大。在同一几何结构的非反应研究中，在远离含有注射蚂蚁的区域的平面荧光图像中发现了反应区，这表明与反应相关的压力上升迫使燃料进行了大量的重新分配。
An experimental investigation of a Mach 2 combustor has been conducted in order to characterize flow properties in a supersonic reacting flowfield. Hydrogen was injected transversely as staged, underexpanded jets behind a rearward-facing step into a ducted Mach 2 air freestream. The effects of the chemical reaction on the supersonic flowfield was investigated using shadowgraphs, broadband flame emission photography, and planar laser-induced fluorescence of OH. The shadowgraphs indicated that the wave pattern in the combustor along with flowfield unsteadiness was strongly affected by the heat release. The broadband flame emission photographs revealed large regions of no combustion in the vicinity of the fuel injectors where fuel/air mixing was insufficient to support combustion. These regions decreased in size as the freestream stagnation temperature was decreased for fixed hydrogen mass flow rate, consistent with an increase in the effective g-ratio with combustion. The size of the zones containing OH in the planar fluorescence images also increased as the main flow stagnation temperature was decreased. Reaction zones were found in the planar fluorescence images away from regions containing inject ant in a nonreacting study of the same geometry, indicating that the pressure rise associated with the reaction forced a large redistribution of the fuel.