S弯喷管与飞机后机身一体化构型红外辐射特性研究

To investigate the infrared radiation characteristics of the serpentine nozzle integrated with the rear fuselage of the wing-body fusion aircraft， this study used the discrete transfer method to calculate the wall， gas and total infrared radiation intensity distribution characteristics of the integrated configuration. The infrared contributions of different components of the integrated configuration were further decomposed. The infrared images were also obtained. The results reveal that the dominant source of infrared radiation of the integrated configuration is the wall radiation from high-temperature components， while gas radiation plays a relatively minor role. The distribution characteristics of total infrared radiation and infrared imaging are primarily influenced by wall radiation. The rear fuselage affects the infrared characteristics of the original serpentine nozzle， with the total radiation peak observed at a 10° detection angle on the vertical detection plane. The integrated asymmetric relative difference between the positive and negative ranges on vertical detection surface reached 56%. The aft deck heated by high-temperature gas becomes the important radiation source in the integrated configuration. Together with the serpentine nozzle wall， it contributes more than 95% of the wall infrared radiation. Notably， the aft deck alone accounting for 35.6% of the infrared contribution on the vertical detection plane. The high infrared radiance area in the infrared image are concentrated in the nozzle throat， nozzle side wall and aft deck. After the integrated design of serpentine nozzle and rear fuselage， the plume has a 5° vector angle， and the gas radiation peak appears at 5° detection angle on vertical detection plane.