Infrared radiation coanda suppressor
AssigneeNorthrop Grumman Corporation
InventorsJonas Bilenas, Robert Kosson, Salvatore Attard
Life of this patent
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Abstract
An infrared radiation Coanda suppressor of an exhaust system encloses a Coanda surface for guiding exhaust gases into the atmosphere. The infrared radiation suppressor further uses cooling films for reducing the temperature of the Coanda surface and other exposed surfaces. A cool air entrainment flow of the exhaust gases prevents the buildup of recirculating hot gases in the exhaust chamber. As a result, IR radiation is suppressed from areas of the exhaust system which are exposed to IR detectors.
Claims4
Apparatus utilizing the Coanda effect for suppressing the emission of infrared radiation from surfaces affected by hot exhaust gases of an engine, comprising:
- an enclosure having an opening to atmosphere;
- exhaust means projecting into the enclosure but away from the opening and outside the line of sight thereof for molding the hot exhaust gases from the engine into a fluid sheet;
- a Coanda surface extending from the molding exhaust means for directing the fluid sheet curvilinearly into the atmosphere through the opening of the enclosure;
- and
- a first inlet aligned with the Coanda surface for injecting cool air onto the Coanda surface, in the direction of the exhaust gases for forming a first laminar cooling film between the exhaust gas fluid sheet and the surface.
Method of suppressing infrared radiation emitted from an exhaust outlet heated by hot exhaust gases of an engine, comprising:
- enveloping the exhaust outlet of the engine in an enclosure having an opening to atmosphere;
- molding the hot gases from the exhaust outlet into a fluid sheet;
- guiding the fluid sheet along a Coanda surface curvilinearly through the opening of the enclosure to the atmosphere;
- and
- injecting, alongside the surface of the Coanda surface, a first laminar film of cooling air between the Coanda surface and the fluid sheet.
Dependencies are inferred from the claim text.