A review of research progress in the design of the exhaust system for the scramjet and turbine based combined cycle (TBCC) engine is presented. Firstly, the technical challenges encountered in designing the exhaust system for a hypersonic propulsion system are highlighted and discussed, and the performance parameter definition as well as the theoretical thrust prediction for the exhaust system is introduced. The review of scramjet nozzle focuses on three aspects: 1) the design method of the single expansion ramp nozzle (SERN) for the integration of the airframe with the propulsion system, in which the design method developments of the two-dimensional (2D) SERN, SERN with lateral expansion and three-dimensional (3D) SERN with shape transition are all summarized; 2) the unique flow phenomena of the scramjet nozzle, including the nonuniform inflow and chemical nonequilibrium flow in SERN; 3) the coupling and interaction of the internal flow with the external freestream. Besides, the design and flow researches of the TBCC exhaust system is also reviewed for three parts: 1) variable geometry design for wide flight range, in which both a 2D and 3D exhaust system are described; 2) the overexpanded flow separation mechanism and its control at low flight Mach number; 3) mode transition from low-speed flowpath (LSF) to high-speed flowpath (HSF) for over-under exhaust system. Through the above summary and analysis, the current status, bottlenecks, and development trend of the exhaust system for an airbreathing hypersonic propulsion system can be further clarified.

综述了超燃冲压发动机和涡轮联合循环（TBCC）发动机排气系统设计的研究进展。首先，重点讨论了高超声速推进系统排气系统设计中遇到的技术挑战，介绍了排气系统的性能参数定义和理论推力预测。超燃冲压发动机喷管的综述主要集中在三个方面：1）用于机身与推进系统集成的单膨胀坡道喷管（SERN）的设计方法，其中二维（2D）SERN的设计方法发展，具有横向扩展的SERN和具有形状过渡的三维（3D）SERN都进行了总结；2）超燃冲压发动机喷嘴独特的流动现象，包括SERN中的不均匀流入和化学非平衡流动；3）内部流与外部自由流的耦合和相互作用。此外，还从三个部分回顾了TBCC排气系统的设计和流动研究：1）宽航程的可变几何设计，其中描述了2D和3D排气系统；2）低飞行马赫数下过膨胀流分离机制及其控制；3）上下排气系统从低速流路（LSF）到高速流路（HSF）的模式转换。通过以上总结和分析，可以进一步明确吸气式高超声速推进系统排气系统的现状、瓶颈及发展趋势。