中文摘要：

单边膨胀喷管（Single Expansion Ramp Nozzle,SERN）是1种新型的排气喷管,具有可以有效抑制航空发动机排气系统的红外辐射和雷达反射截面积、后体阻力小、质量轻、增加飞机的敏捷性和可操控性等优点。运用计算流体力学/红外辐射（CFD/IR）数值模拟的方法,采用标准k-ε湍流模型和标准壁面函数,研究了轴对称喷管、单边膨胀喷管和开缝冷却单边膨胀喷管的排气系统与机身融合后的红外辐射特性空间分布规律。结果表明：单边膨胀喷管大幅度降低了排气系统尾向红外辐射峰值,其降幅达到60%以上,说明了单边膨胀喷管与后机身融合、遮挡内部高温部件,从而降低了尾向红外辐射的卓越红外抑制效果。

英文摘要：

Single Expansion Ramp Nozzle（SERN） is a new style exhaust nozzle which has a lot of advantages.It can suppress the infrared radiation,reduce the radar cross section,decrease the resistance of the nozzle＇s after body,reduce the whole weight.The non-symmetry of the nozzle can improve the agility and maneuverability for the planes.Based on the computational fluid dynamics/infrared radiation（CFD/IR） numerical calculations,using standard κ-ε turbulent model and standard wall functions,three kinds of nozzle within the aircraft which were axis symmetry nozzle,single expansion ramp nozzle and single expansion ramp nozzle with cooling were performed to simulate the infrared radiation distribution of the plume and exhaust system.The results show that the SERN has the ability of shield the high temperature parts located in the nozzle.It can suppress the infrared radiation by 60% of the exhaust system.