GB774756A - - Google Patents

Abstract

774,756. Gas turbine jet propulsion engines. SOC. NATIONALE D'ETUDE ET DE CONSTRUCTION DE MOTEURS D'AVIATION. July 27, 1955 [July 28, 1954], No. 21729/55. Addition to 716,456. Class 110 (3). [Also in Group XII] A ducted fan gas turbine jet propulsion engine as claimed in the parent Specification comprising a gas turbine unit and a duct by-passing the unit and supplied with air by the fan and one or more pulse jets in the duct discharging through ejector nozzles coaxial with the pulse jets has fuel injected into the exhaust gases of the pulse jet units upstream of the outlet of the ejector nozzles. A low-pressure compressor 2 driven by a turbine 8 through reduction gearing 8c supplies air to a highpressure compressor 1 and to a duct 6 leading to an annular discharge nozzle 15. The highpressure compressor 1 supplies air to a combustion chamber 7 feeding the turbine 8. The duct 6 contains a number of pulse jet units each comprising a pulsatory combustion chamber 10, an aerodynamic inlet valve 11 and exhaust pipe 13. The exhaust pipes 13 discharge into ejectors 17 which also receive some of the air passing through the duct 6 around the pulse jet units. The remainder of the air passes around the ejectors to the annular discharge nozzle 15. To augment the thrust fuel injectors 38 are arranged to discharge into the forward part of the ejectors. The ignition is automatic when the chambers 10 are in operation. Normally the wake caused by the ejectors is sufficient to stabilize the flame but stabilizing screens may be provided if necessary. The injectors 38 may be arranged on the upstream side of the ejectors between the outlets of the pipes 13 and the inlets of the ejectors, in the pipes 13 or in the divergent portions 36 of the ejectors. The supplementary fuel may be injected at low pressure without atomization and the injectors may be simple freely open tubes which may be directed in any direction into the gas flow.