针对三维并联TBCC排气系统，基于几何约束下的轴对称最大推力基准流场，利用双向流线追踪方法设计了圆转矩三维非对称喷管，并对其进行尾缘斜切修型以改善气动性能同时降低喷管重量。在此基础上，利用共用面绕后端点转动的方式实现涡轮通道的变几何调节，从而完成排气系统设计。随后，通过风洞冷流试验获得了典型工况下排气系统的壁面压力分布和流场纹影；并通过数值模拟获得了详细的流场特征和性能参数。结果表明，各工况点下的流场纹影、沿程压力分布与数值仿真结果吻合较好；排气系统涡轮通道单独工作时，排气射流结构较为简单，在低落压比下出现激波串结构；双通道共同工作时，两个通道的排气射流相互干涉；在冲压通道单独工作阶段，气流在三维流道内膨胀较为流畅。排气系统推力性能在涡轮和冲压发动机共同工作工况略有恶化，但在整个工作包线内推力系数均在0.924以上且变化平稳。本研究为TBCC排气系统提供了一种新的有效方案。

Based on the axisymmetric flowfield with optimal thrust under geometric constraints, a circular-to rec-tangular three-dimensional single expansion ramp nozzle is designed by using the streamline tracking method, and trimming the configuration of nozzle to improve the aerodynamic performance and reduce the weight of the nozzle. On this basis, the adjustment programme for changing geometry of the turbojet flowpath is achieved by using the rotating ramp rotation around the ramp endpoint to complete the design of the exhaust system. Subsequently, the wall pressure distribution and schlieren image of the exhaust system are obtained through cold flow experiments, and the detailed flow field characteristics and performance parameters are obtained through numerical simulations. The results show that the schlieren image and pressure distributions of the wall under each operating condition are in good agreement with the numerical simulation results; when the turbojet works alone, the structure of the exhaust jet is relatively simple, and there will be a shock train structure under the low nozzle pressure ratio(NPR); In parallel operation, the two flowpath interfere with each other; in separate operation of ramjet, the airflow expands smoothly in the three-dimensional flow path. The thrust performance of the exhaust system deteriorates slightly in the turbine and ramjet co-operating condition, but the thrust coefficient is above 0.924 in the whole working envelope, and the thrust performance changes smoothly. This study provides a new effective solution for the TBCC exhaust system.