宽马赫数范围高超声速进气道伸缩唇口式变几何方案

A Variable Geometry Scramjet Inlet with a Translating Cowl Operating in a Large Mach Number Range

针对二元高超声速进气道Ma=4～7的宽马赫数范围工作要求,探索了一种伸缩唇口式简单变几何方案,利用一维流理论对其设计方法进行了讨论,给出了一种具体的实现方案,并利用数值仿真手段对其接力点下的自起动性能及其它不同工作马赫数下的性能进行了研究。结果表明:(1)所设计的伸缩唇口式变几何方案解决了宽马赫数工作范围内定几何进气道难以协调的设计矛盾,该方案能使进气道工作范围进一步拓宽至Ma=4～8(9);(2)变几何进气道能使马赫4接力点下的流量系数保持在0.7以上,这为飞行器宽马赫数范围加速提供了强有力保障;(3)与定几何进气道相比,变几何进气道高低马赫数下的总体性能均得到大幅度提高;(4)研究发现,附面层排移及排移位置对改善进气道接力点下的自起动性能有重要影响。

A two-dimensional variable geometry scramjet inlet with a translating cowl operating in a large Mach number range from 4 to 7 is designed.The inlet uses a movable cowl to adapt contraction ratio to different incoming Mach numbers.During the inlet design,an one-dimensional flow theory is used to analyze the distribution of internal and external compression.The self-starting characteristics at Ma=4 and the global performance of the variable geometry inlet are studied by means of numerical simulations.Results indicate：（1） the variable geometry inlet resolved the difficulties occurred in the fixed geometry inlet design,and its operating rang could be further extended to Ma=4～8（9）;（2） The variable geometry inlet achieved a mass capture ratio of 70 percent at the staring Mach number,which was very favorable to the acceleration of the hypersonic vehicles operating in a large Mach number range;（3） The global performance parameters of the variable geometry inlet are greatly increased in the whole operating range compared with the fixed geometry inlet;（4） Part removing of the boundary layer obviously improved the inlet self-starting characteristics.The removing position also has a great effect on the improving degree.