Abstract: The present invention is a hover infrared suppression system for a gas turbine engine comprising a hover infrared suppression system having an upstream first stage, a second stage downstream of the first stage and a third stage downstream of the second stage, the engine operating at a temperature sufficient to cause the hover infrared suppression system to emit infrared radiation. The present invention further comprises a high reflectivity coating applied over a preselected area of at least one of the stages of the hover infrared suppression system to reduce the infrared radiation emitted from the engine, the high reflectivity coating being fired after application.

Abstract: A method for suppressing infrared radiation from an aircraft engine includes directing hot exhaust from the aircraft engine into a lobed mixer of a single baffle infrared suppressor having a single baffle assembly to generate alternating flows of hot exhaust gas and cold air. The method further includes directing the alternating flows of hot exhaust gas and cold air towards the single baffle assembly to mix the hot exhaust gas with the cold air.

Abstract: A high emissivity (Hi-E) coating for use on the exhaust baffles of HIRSS systems. HIRSS systems were developed to reduce the infrared (IR) signature of helicopter engines. Increasing operating temperatures of helicopter engines have made the HIRSS systems less effective. An infrared coating applied over selected portions of the HIRSS reduces the IR of the system. The Hi-E coating comprises, in weight percent, 30-80% refractory oxide pigment, 5-20% binder, 1-15% potassium oxide, optionally up to about 15% glass-forming material and the balance refractory oxide powder. When applied to provide a surface finish of 1100Ra microinches or coarser, the coated HIRSS has a significantly reduced hemispherical reflectance in the IR frequency range.

Abstract: An infrared signature suppression system for reducing infrared radiation emitted by a vehicle. The system includes an elongate duct mounted on the vehicle having a hollow interior extending along an axial centerline between an upstream end and a downstream end for transporting exhaust gas emitted by the vehicle, and a baffle positioned in the hollow interior of the duct between the upstream end and the downstream end. At least a portion of at least one of the duct and the baffle includes an emissivity coating for reducing infrared radiation emitted by the vehicle.