Susceptibility of combat aircraft modeled as an anisotropic source of infrared radiation

This paper describes the analysis of susceptibility of a supersonic aircraft to infrared (IR)-guided missiles by considering the aircraft as an anisotropic IR source. Supersonic aircraft have been considered as point sources in previous analyses; however, this assumption results in an overestimation of susceptibility. The procedure described here addresses this overestimation problem, and a more detailed susceptibility analysis was conducted. Detailed temperature distributions, including aerodynamically heated surfaces and hot engine parts, were obtained by coupled simulations of computational fluid dynamics with a radiation and conduction solver. Using the calculated surface temperature of the aircraft, the IR signature levels were calculated in the mid-wavelength IR and long-wavelength IR bands as a function of the detection aspect. A susceptibility analysis was carried out that considered the burnout range of air-to-air missiles to determine the lethal range. The lethal range was investigated for both the MWIR and LWIR bands and for various detection angles, including the frontal and rear aspects. An effective method to decrease susceptibility using IR signature-reduction technology was identified by comparing the changes in the lethal area of each detection band and aspect.