GB801040A - Improvements relating to gas turbine engines - Google Patents

Abstract

801,040. Gas turbine plant. BIRTWISTLE, J. R. Oct. 16, 1956 [Oct. 22, 1955], No. 30261/55. Class 110 (3). [Also in Group XII] A gas turbine engine comprises a nozzle adapted alternately to convey air from a supply duct to a combustion chamber and to discharge gas from the combustion chamber through the duct to a diffuser, a second nozzle conveying gas from the combustion chamber to the same or another diffuser, and a duct leading from the diffuser or diffusers to a turbine. Air from a compressor passes by way of a duct 1, Fig. 1, and a nozzle 2 to a combustion chamber 4, while the exhaust gas from the last cycle of operation continues to flow out through a nozzle 5. At the same time, air from duct 1 flows through a nozzle 3 and mixes with the exhaust gas in a duct 7. Fuel is then rapidly injected into the combustion chamber 4 and ignited by a device 10, and the subsequent rise in pressure causes the gas to flow outwards through the nozzles 2 and 5 and then through diffusers 3 and 6 and the duct 7 to turbine guide vanes 8. The gas pressure drops through the nozzle 2 to that of the air supply and increases again through the diffuser 3, so that flow of air from the duct 1 almost ceases during this part of the cycle. The cycle is then repeated. The nozzle 2 and diffuser 5 may be designed for either subsonic or supersonic conditions. A regenerator may be provided in duct 7 or that part of duct 7 receiving gas from diffuser 3 only, to reduce the temperature variation. In a modification, Fig. 2, the nozzles 2 and 5 are concentric, and gas from the periphery of the cylindrical combustion chamber 4 is guided to the nozzle 2 by a baffle 11. The nozzles 2 and 5 discharge to a common diffuser 13 which is preceded by a cylindrical section 12 to improve the mixing of the gas with any entrained air. In a further embodiment, the combustion chamber, nozzles, diffusers and air supply duct are of annular form.