基于超燃冲压发动机的HIFiRE项目飞行试验研究进展

飞行器在临近空间内的气动特性及发动机性能一直是各国高超声速项目研究的重点，为探索边界层转捩、激波边界层相互作用以及气动加热效应，美澳牵头于2006年联合启动了HIFiRE项目，采用探空火箭发射进行重点技术验证的模式开展了系列创新性研究。项目重点关注20~38km空域，4~8速域飞行马赫数，试验方案通过单项验证、系统集成的思路逐步深入，将一体化设计的乘波体从无动力滑翔推进到有动力巡航，最终完成带超燃冲压发动机高升阻比飞行器的总体性能测试。研究结果表明:①试验飞行器的边界层转捩高度在35~25km；②乘波体飞行器在飞行马赫数为7时最大升阻比为5.6；③超燃冲压发动机的飞行试验中，在86.2kPa的恒定动压下,飞行马赫数从5.5加速到8.5，试验中发动机实现了从亚燃到超燃的模态转换。 

Research progress on flight tests of HIFiRE project based on scramjet

The aerodynamic characteristics and engine performance of the vehicle in the nearspace have been the focus of the research on the hypersonic projects in various countries. To explore the boundary layer transition, the shock boundary layer interaction and the aerodynamic heating effect, America and Australia led a project called HIFiRE in 2006 and investigated a series of innovation for this kind of vehicles by using sounding rocket to verify key techniques. Height range 20-38km and speed range flight Mach number 4-8 were the major concerns. Flight test scheme was arranged with the method of single technology verification and system integration. With the combination of propulsion system, the gliding waverider carried out cruise flight, at last, overall performance of high lift-to-drag ratio vehicle with scramjet was tested at hypersonic speed. The results showed that: (1) the boundary layer transition height of the test vehicle was in the range of 35~25km; (2) the maximum lift-to-drag ratio of waverider-body vehicle at flight Mach number 7 was 5.6; (3) during the flight test of scramjet, the speed of the vehicle was accelerated from flight Mach number 5.5 to flight Mach number 8.5 at a constant dynamic pressure of 86.2kPa, and the engine realized mode transition from sub combustion to super combustion.