Experimental testing of an airframe-integrated three-dimensional scramjet at Mach 10
Experimental testing of an airframe-integrated three-dimensional scramjet at Mach 10
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DOI：
10.2514/1.j053785
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发表时间：
2015-09
期刊：
影响因子：
2.5
通讯作者：
L. Doherty;M. Smart;D. Mee
中科院分区：
文献类型：
--
作者：
L. Doherty;M. Smart;D. Mee
在一台小型机身一体化三维超燃冲压发动机的激波风洞中进行了自由喷流试验。调查的目的是检查机身一体化对发动机运行的影响。这些测试是在模拟飞行条件下进行的，飞行速度为10.4马赫，动压为48千帕。内部流道包括设计用于12马赫飞行的矩形到椭圆形过渡进气道，具有恒定面积和扩张截面的椭圆燃烧室，以及三维推力喷管。这条流道与前身和流线型外部几何结构整合在一起，类似于飞行器上的预期。气态氢燃料要么通过进气口的舷窗喷射，要么通过燃烧室入口处向后台阶后面的一系列舷窗喷射的组合。在一系列燃料当量比下的实验表明，两种燃料喷射方案都在不使用点火助燃剂的情况下产生了强劲的燃烧。与带有截断前身的三倍比例发动机的半喷流试验相比，在目前的试验中，总体燃烧产生的压升略有降低。这些结果表明，机身一体化不会导致该发动机性能的显著下降。
Freejet experiments have been conducted in a shock tunnel with a small airframe-integrated three-dimensional scramjet engine. The goal of the investigation was to examine the influence of airframe integration on the engine operation. The tests were conducted at a condition replicating flight at Mach 10.4 and a dynamic pressure of 48 kPa. The internal flowpath featured a rectangular-to-elliptical shape transition inlet designed for flight at Mach 12, an elliptical combustor with a constant area and diverging section, and a three-dimensional thrust nozzle. This flowpath was integrated with a forebody and streamlined external geometry similar to what would be expected on a flight vehicle. Gaseous hydrogen fuel was injected either through portholes on the inlet or a combination of inlet injection with a series of portholes behind a rearward-facing step at the combustor entrance. Experiments at a range of fuel equivalence ratios indicated that both fuel-injection schemes produced robust combustion without the use of ignition aids. Comparison with semifreejet tests of a three-times scale engine with a truncated forebody showed a slight reduction in the overall combustion generated pressure rise in the current experiments. These results indicate that airframe integration does not lead to significant degradation in the performance of this engine.