关于超声速燃烧与高超动力

先进发动机是航空工业的核心技术, 而吸气式高超声速发动机一直是宇航飞行技术研发的首位难题. 发动机的性能依赖于其能量转换模式和燃烧组织方法, 相关理论研究具有基础性和启发性意义. 论文首先讨论了超声速燃烧, 它一直是超燃冲压发动机技术的理论基础. 然后综述了相关研究进展, 提出了吸气式高超声速冲压推进技术的3个临界条件, 或者称为临界参数. 第一临界条件针对超声速气体流动中燃烧发生部位的亚声速或超声速状态的判定问题, 由此可以揭示上行激波的产生机制, 也能够作为燃烧后气体流动状态的判定条件; 第二临界参数定义了在当量比燃烧条件下吸气式高超声速冲压发动机的稳定运行马赫数, 是发动机设计需要考虑的必要条件. 第三临界参数给出了对应CJ斜爆轰的楔面角度, 其物理基础是爆轰临界起爆状态. 最后总结了驻定斜爆轰冲压发动机的实验研究进展, 论述了作为未来高超声速飞行动力的可行性. 

On supersonic combustion and hypersonic propulsion

The advanced engine has been the core technology of the aviation industry for several decades. The air-breathing hypersonic propulsion is the top problem for future aerospace flight. The engine's performance depends on its energy conversion method and combustion mode, and its relevant theory is of fundamental and revealing significance. In this paper, the supersonic combustion is discussed first since it is the theoretical basis for the research and development of scramjet engines. Then, by reviewing related research progresses, three criteria of the air-breathing hypersonic ramjet propulsion are established. The first one can be used to determine the local subsonic or supersonic flow states of combustion products in supersonic reacting gas flows, revealing the mechanism of the upstream-traveling shock wave. The second one defines the critical Mach number for hypersonic ramjet operation for all the combustion modes, and is a necessary condition that needs to be considered in the engine design under the equivalent ratio combustion. The last one gives a critical wedge angle corresponding to the CJ oblique detonation, and its physical basis is the critical initiation state of detonation. Finally, the experimental research progress on the stationary oblique detonation ramjet (Sodramjet) engine is summarized, and its feasibility as a hypersonic engine for future aerospace flight is demonstrated.