Infrared Viewer for Turbine Engine Internal Surfaces

The development of an instrument for mapping the infrared radiance field from interior surfaces of turbine engine exhaust cavities is proposed. The instrument will consist of a cooled, rotating optical head that will traverse along the axis of the engine exhaust, mapping the infrared radiance from the surface in 2-square-centimeter spatial resolution elements over a wavelength range of 2.5 to 14 microns. The device will be ruggedized and deployable so that its utility will not be limited to engine test cells but could also be used in the field. In order to accomodate the requirements for survivability and accuracy in a harsh environment, the infrared sensor head will be remote from the optical probe and connected by an optical relay system. The optical head will utilize a film-cooled window to provide an adequate signal-to-noise ratio. Along the optical path, the internal optical cavities will be cooled using water jackets to ensure an adequate signal-to-noise ratio. This instrument should provide a capability of taking rapid (under 60 seconds) scans of the internal radiance field inside jet-engine exhaust cavities.