多模态冲压发动机提高性能的技术途径

为了使高超声速冲压发动机在宽飞行条件下同时具有高比冲、高推力系数、高推重比，在讨论多模态冲压发动机的不同工作模态特性基础上，提出了改进进气道／燃烧室／尾喷管参数协调状态的技术途径。在固定几何的条件下，采用一体化设计内流通道，并巧妙地调节加热规律，使得在不同飞行条件下采用不同的优化工作模态，从而防止进气道出现亚 声速溢流或过度超临界，防止尾喷管产生膨胀过度或不足，防止燃烧室内的过度高温高压，并使冲量增量最大。此外，就国内外在研制过程中曾出现过经验教训及应引起关注的技术创新点进行了讨论。

Development and innovation of multi-mode ramjet technology

In order to reach simultaneously high performances (specific impulse, thrust coefficient, thrust/weight ratio) for the hypersonic ramjet under wide range flight condition, it is necessary to match the parameters of inlet/combustor /nozzle based on the characteristics of multi mode operation. Under the condition of fixed geometry, the integrated internal flow path should be designed,and the heating process has to be sophisticatedly adjusted. Thus, different optimal operation mode should be adopted for different flight condition to prevent the subsonic spillage or extreme supercritical condition in the inlet, the over or under expansion in the nozzle, the extreme high temperature and pressure in the combustor, and to obtain maximum impulse increase. Due to the complexity of the hypersonic propulsion technology, lots of experiences and lessons occurred during research and development in domestic and foreign countries, the technical innovation should be pay attention and carried out.