Variation of Supersonic Aircraft Skin Temperature under Different Mach number and Structure

Abstract

Stealth technology of combat aircraft is most significant capability in recent air battlefield. As the detector of IR missiles is being developed, IR stealth capability which is evaluated by IR signature level become more important than it was in previous generation. Among IR signature of aircraft from various sources, aerodynamic heating dominates in long-wavelength IR spectrum of 8～12μm. Skin temperature change by aerodynamic heating which is derived by effects of Mach number and structure. The 4th and 5th generation aircraft are selected for calculation of the skin temperature, and its height and velocity in numerical conditions are 10,000 m and Ma 0.9～1.9 respectively. Aircraft skin temperature is calculated by computing convection of fluid and conduction, convection and radiation of surface. As the aircraft accelerates to higher Mach number, maximum skin temperature increases more rapidly than average temperature and temperature distribution changes in more sharp, interactive ways. The 4th generation aircraft whose shape is more complex than that of the 5th generation aircraft have complicated temperature distribution. On the other hand, the 5th generation aircraft whose shape is relatively simple shows plain temperature distribution and lower skin temperature in terms of both average and maximum value.

Long wave infrared signature of swept back leading edges in aircraft frontal aspect

“…The temperatures of aerodynamically heated SBLE are lower than those of aircraft nose, but because of its large surface area (relative to the nose), SBLE can be easily used to engage an aircraft from the front using an LWIR-guided missile. Cha et al (2014) studied skin friction heating for different airframe configurations (fourth- and fifth-generation aircraft) and enhancement in their LWIR signatures because of increasing Mach number ( M ∞ = 0.9–1.9). Tauber et al (1987) estimated the equilibrium wall temperature, T w at emissivity, ε = 0.8, to identify the heating load on the stagnation surface, wing leading edges, and bottom surface of a trans-atmospheric vehicle (TAV) because of aerodynamic heating.…”

A novel detection performance modular evaluation metric of space-based infrared system

“…The fuselage is flying parallel to the sea. Considering the F22's strong infrared stealth capability, this paper sets the infrared emissivity of the skin to 0.5, and the diffuse reflectance of the fuselage is 0.2 (Li, N. et al 2015;Baranwal, N. et al 2015;Cha, J. H. et al 2014;Pan, X. et al 2015;Wu, K.F. et al 2020).…”

Detection spectrum optimization of stealth aircraft targets from a space-based infrared platform

“…F22, as a typical fifth-generation fighter aircraft, is selected to be the aircraft target. The infrared emissivity of the F22's skin is set to 0.5 (Baranwal, N. et al 2015;Li, N. et al 2015;Cha, J. H. et al 2014), the speed is Mach 1, and the plume temperature is 1300K. The superiority of the proposed method is illustrated by comparing it with the traditional fixed-spectrum detection system.…”