Improvements in gas-turbine engines

728,451. Gas turbine jet propulsion plant. SOC. NATIONALE D'ETUDE ET DE CONSTRUCTION DE MOTEURS D'AVIATION. March 7, 1952 [March 16, 1951], No. 6042/52. Class 110 (3). [Also in Group XII] A gas turbine engine comprises a turbine, a compressor discharging into several pulsatory combustion chambers disposed about the turbine axis together with means for utilizing the turbine exhaust energy. Each combustion chamber discharges through a freely open expansion nozzle toward a part of the turbine blading, the expansion nozzle being adapted to transform into kinetic energy at least the energy which corresponds to the pressure waves in the corresponding chamber. The exhaust utilising means may comprise a further turbine wheel or a propulsion nozzle or both. Air sucked through the diffueer 1 is compressed in a centrifugal compressor 2 and discharged into an annular manifold 3 from which it passes into the pulsatory combustion chambers 4 arranged around the shaft of the engine through aero-. dynamic valves 6. The combustion chambers 4 discharge through freely open. exhaust pipes. and expansion nozzles 5 into an annular manifold 7a. The combustion chambers 4 may be fed with gasoline, petrol, oil, fuel oil or pulverized coal through ducts 4a and may be automatically ignited from one another by means of tubes 22. The nozzles 5 expand the combustion gases from the maximum pressure in the combustion chambers down to the compressor discharge. The stator blades 7 deflect the gases on to the turbine wheel 8a which exhausts into an annular manifold 9 from which they pass on to one or more turbine wheels 10. The turbine wheels 10 drive the compressor 2 and a propeller through a shaft 16. The turbine 8a is connected to the shaft 16 through step-up gearing 15. Air from the discharge of the compressor 2 is passed through casings surrounding the combustion chambers and mixed with the combustion gases by means of apertures 18 before' they pass through the nozzles 5. The gases, collected, in the manifold 9 are diluted with air from the discharge of the compressor supplied through a duct 12 and apertures 11 before passing to the turbine wheels 10. The exhaust 'gases from the turbine wheels 10 are expanded in a propulsion nozzle 13. The blades of the turbine 8a are cooled by air supplied to passage 20, 20a through apertures 23 and ducts 24. The plant is started by injecting compressed air and fuel into one or two of the pulsatory combustion chambers and igniting the mixture by spark p