针对航空发动机尾喷管长寿命及高红外隐身需求，开展了超声速矢量喷管扩张段冷却次流与主流干涉复杂流场结构分析研究，进一步探讨了复杂流场与喷管冷却特性、气动特性、后向红外辐射强度的关联关系。结果表明，保持主次流进口参数不变，冷却次流入射超声速主流形成诱导激波/膨胀波束，复杂波系与喷管壁面相交点随矢量角增大逐渐前移，壁面冷却效率在交点处随边界层抬升而降低；喷管主流经过复杂波系产生额外流动损失，喷管推力系数和总压损失相对于无冷却状态下降。次流从扩张段壁面上游入射相对下游入射冷却效率更低，但覆盖范围更广；三股次流同时入射使得喷管扩张段上下壁面平均冷却效率达到0.9075和0.9121，相对于单股次流入射上下壁面平均冷却效率，最高可提升92.55%和98.37%，而前者由于主流过多道激波，相对于单股次流冷却推力系数最高下降1.62%，总压恢复系数最高下降2.20%。对比主流工质为空气和燃气的工况，后者在次流充分发展阶段引起壁面沿程冷却效率下降，但喷管推力系数有所提高。喷管后向红外辐射亮度与喷管流场结构相对应，冷却次流入射使得喷管后向平均总辐射强度在1~3μm、3~5μm、8~14μm波段，俯仰平面内分别下降67.39%、56.58%、56.68%，偏航平面内分别下降26.77%、23.88%、23.24%。研究结果可为矢量喷管的冷却结构设计提供理论依据和基本数据库。

To meet the requirements of long life and high infrared stealth of the aero-engine nozzle, the complex flow field for which the secondary flow injecting into the supersonic mainstream of a vector nozzle is studied in detail. The relations between the flow field of the nozzle and the film cooling performance, the aerodynamic performance, and the infrared radiation intensity are further discussed. The results show that with constant inlet conditions for the coolant flow and the main jet, the secondary inflow induces shock wave/expansion waves when injecting into the main jet. The complex waves impinge on the nozzle wall and the impingement location moves forward when the nozzle vector angle increases. The film cooling effectiveness decreases as the boundary layer is raised due to the impingement of the waves. The complex waves cause extra pressure loss in the main jet, which leads to a decrease of the thrust coefficient and an increase of the total pressure loss. Compared to the downstream secondary flow injection, the upstream secondary flow injection results in a lower film cooling effectiveness, but a larger coolant coverage. The secondary flow injecting from three slots achieves an averaged cooling effectiveness of 0.9075 on the upper wall, and an averaged cooling ef-fectiveness of 0.9121 on the lower wall of the nozzle. Compared to the secondary flow injecting from a single slot case, the highest increments of the averaged cooling effectiveness are 92.55% and 98.37% on the upper wall and lower wall of the nozzle, while the highest decrements are 1.62% and 2.20% for the thrust coefficient and the total pressure re-covery coefficient. When the working medium is gas for the main jet, the cooling effectiveness is decreased in the well-developed region, while the thrust coefficient is increased compared to the case with the working medium of air. The brightness of the infrared radiation corresponds to the flow field of the nozzle. For the wave bands 1~3μm, 3~5μm, and 8~14μm, the injection of the secondary flow leads to decreases of the averaged radiation intensity of 67.39%, 56.58%, and 56.68% in the pitch plane, and 26.77%, 23.88%, and 23.24% in the yaw plane. The work can be a reference for the design of cooling configurations for a vector nozzle.