几何参数对S弯喷管红外辐射特性的影响

In order to acquire the infrared signature of serpentine nozzle, the study on the effects of the length ratio and the centerline on the infrared signature of serpentine nozzle had been performed. The results show that the gas infrared signature in the horizontal plane reduces by 61.1% on average when compared with that in the vertical plane. Otherwise, in the vertical plane, the wall infrared signature at negative azimuth angle is greater than that at positive azimuth angle. The relative differences of total infrared radiation intensity between the serpentine nozzles with different length ratio and centerline are between 2.2% and 6.3%. The length ratio and the centerline have significant influences on the flow performance, but their effect on the infrared signature is limited. And these two design parameters can be ignored in the design process of serpentine nozzle on the view of infrared suppression.