Numerical Simulation on the Infrared Radiation Characteristics of S-Shaped Nozzles

Abstract

Infrared stealth is of great importance to increase the survival ability of the aircraft. The exhaust system is the main radiation source of the aircraft at the rare hemisphere. A program using reverse Monte-Carlo method was developed to calculate the infrared radiation intensity of afterburning turbofan engine under non-afterburning condition, and simulate axisymmetric nozzle and three S-shaped nozzles with different relative eccentric distances. The results demonstrate that: the infrared intensity of S-shaped nozzle is much lower than that of axisymmetric nozzle; S-shaped nozzle can effectively reduce the maximum of IR intensity in the rear hemispheric space; the S-shaped nozzle with the relative eccentric distance of 0.5 can reduce the intensity of infrared radiation in critical detection directions effectively.