Using extended surfaces to reduce the thermal signatures of military assets

Abstract

Because military assets often operate at temperatures different from their surroundings, they exhibit thermal signatures observable with infrared (IR) imaging systems operating in the mid-wave (MWIR) and long-wave (LWIR) infrared bands of the spectrum. Reducing these thermal signatures provides a means of making these assets blend in with their environments. Most often the assets are warmer than their environment because they must dissipate heat generated internally from electronics, engines, or personnel. The radiation emitted by these assets is strongly dependent on the temperature and the emissivity of the exposed surfaces. Thus, by reducing the emissivity or the temperature, or both, the thermal signatures can be reduced. The current study addresses the use of extended surfaces, or fins, to reduce the temperature of heat dissipating surfaces. Analytic, experimental, and computational studies are performed which demonstrate that extended surfaces offer an effective way to reduce the temperature of exposed surfaces while still dissipating the heat generated by the asset.