초록 ▼

An aircraft for vertical or short take off and landing operations having two main lift nozzles, both positioned at or near the aircraft center of gravity utilizes one or more jet screen nozzles, arranged in a variety of shapes and combinations, discharging bypass air from a position forward of the c

An aircraft for vertical or short take off and landing operations having two main lift nozzles, both positioned at or near the aircraft center of gravity utilizes one or more jet screen nozzles, arranged in a variety of shapes and combinations, discharging bypass air from a position forward of the center of gravity, and a variable pitch nozzle discharging engine exhaust gas mixed with bypass air from a position aft of the center of gravity, to achieve pitch control while airborne in vertical take off or landing mode. The jet screen nozzle also prevents or reduces ingestion of mixed hot exhaust gas and bypass air discharged through the main lift nozzles. The jet screen nozzle further prevents or reduces ingestion of foreign object debris disturbed by the vertical lift discharge flowing from the main lift nozzles. Lift improvement devices are deployed during short or vertical takeoff and landing operations to act as air dams to cause main lift nozzle discharge striking the ground and returning to the aircraft as a fountain flow and flowing against the lower surface of the aircraft, to separate from the aircraft surface and return toward the ground. This enhances lift effect on the aircraft while avoiding further hot exhaust gas flow along the aircraft skin surface and eventually into the aircraft engine inlet. A control system modulates the jet screen nozzle and aft pitch control nozzle, along with the cruise nozzle, main lift nozzles and other control nozzles so that total engine discharge flow area remains substantially constant through a range of pitch control and other maneuvering commands.

대표청구항 ▼

[ What is claimed is:] [1.] An aircraft engine inlet exhaust gas and foreign body ingestion reduction and aircraft pitch control system for use in a vertical and short takeoff and landing aircraft utilizing a high pressure ratio bypass jet engine defining a longitudinal axis, and including an air in

[ What is claimed is:] [1.] An aircraft engine inlet exhaust gas and foreign body ingestion reduction and aircraft pitch control system for use in a vertical and short takeoff and landing aircraft utilizing a high pressure ratio bypass jet engine defining a longitudinal axis, and including an air inlet for ducting air to the engine, said engine having first and second stage compressors, a bypass duct communicating with the area between said first stage compressor and said second stage compressor and conducting compressed bypass air therefrom to a point aft of the engine, a plenum attached aft of said engine for receiving said bypass air and exhaust gases, a tailpipe attached aft of said plenum, a selectively closable cruise nozzle attached to the aft end of said tailpipe and two controllable lift nozzles positioned in said plenum for selectively diverting mixed engine exhaust gas and bypass air downwardly in a lift column, said aircraft engine inlet exhaust gas and foreign body ingestion reduction and pitch control system comprising:a bypass duct offtake attached to said bypass duct and mounted forward of said two lift nozzles, for diverting a portion of compressed air flow from said bypass duct;a jet screen nozzle connected to said bypass duct offtake to receive bypass air from said bypass duct offtake and discharge said bypass air as a jet screen;a pitch nozzle attached to said tailpipe and oriented to selectively discharge exhaust gases to provide the aircraft a negative pitching moment in response to control commands; anda control system connected to control area pitch nozzle, and said jet screen nozzle for differentially opening and closing said pitch nozzle and said jet screen nozzle to generate positive and negative aircraft pitching moments in response to operator commands while maintaining the total discharge flow area of the high pressure ratio bypass jet engine substantially constant.