Integral infrared radiation suppressor for a turbofan engine

摘要

Apparatus is disclosed for minimizing the infrared radiation emitted at the aft end of a bypass fan type turbine engine. Minimization is accomplished by ducting cool air from the secondary bypass airstream through an annulus to form a sheath of cooler air around the gas stream as it is discharged from the engine tailpipe. The sheath of air educted along the inside surface of the engine tailpipe minimizes infrared radiation in two ways. First it reduces the operating temperature of the tailpipe thus keeping radiation therefrom to a low level. Second, the cool outside air becomes entrained in the hot gas stream discharged from the turbine. This results in a reduction of the effective temperature of the gas plume and suppresses infrared radiation therefrom.