关键词: 飞/发一体化, S弯喷管, 飞机后体, 红外辐射, 红外抑制

Abstract: To investigate the influence of the rear fuselage on the infrared radiation characteristics of S-shaped nozzles in integrated flight/launch vehicle designs, this study employed a scaled test model of the rear fuselage from an S-shaped nozzle flying wing aircraft. Utilizing a partitioned measurement method, experiments were conducted to characterize infrared radiation properties across representative detection surfaces in the rear hemispherical space. Results indicate that the partitioned measurement method resolves the challenge of covering the core region of the tail exhaust plume during wide-angle de-tection. Testing verifies that this method reduces measurement errors attributable to plume radiation by 23.8% within the lower detection plane. The rear fuselage significantly alters the original infrared radiation characteristics of the S-shaped nozzle: At the forward tail direction (α=0°), the heated rear body acts as a secondary radiation source, increasing the peak radiation intensity by 12.3% compared to the model without a rear body. At lateral angles (α>5°), the rear body shields the high-temperature exhaust and wall surfaces, reducing the radiation intensity of the rear fuselage test speci-men by an average of 10.52% and 40.51% on the horizontal and downward detection planes, respectively, compared to the S-shaped nozzle.

Key words: Integrated flight/launch system, S-shaped nozzle, aircraft rear section, infrared radiation, infrared suppression