GB1524956A - Gas tubine engine - Google Patents

Abstract

1524956 Gas turbine engines; cooling turbine structure ROLLS-ROYCE (1971) Ltd 30 Oct 1975 [11 Nov 1974] 48660/74 Heading F1G The invention relates to a gas turbine engine comprising stator structure defining the radially outer wall of the gas flow duct through the turbine, the stator structure including a shroud surrounding the rotor blades, there being air supply passages for cooling the shroud, the air passages having outlets for discharging the cooling air into the gas flow duct upstream of the rotor blades. In Fig. 2 the turbine comprises a rotor having blades 18 and inlet guide vanes 15 disposed in gas flow duct 21. The stator casing is shaped to provide two annular chambers 24, 25 separated by a wall 23A, also a shroud ring 22 disposed around the rotor blades. A series of tube members 27 extend across the chamber 25 each tube having discharge orifices 29 directed towards the outer surface of the shroud ring 22, so that cooling air supplied through chamber 24 and tubes 27 discharges through orifices 29 to impinge against the shroud ring. The cooling air then discharges from the chamber 25 through a series of orifices 32 disposed upstream of the rotor blades 18. The orifices 32 are so inclined as to direct the cooling air in the same direction as the gas discharge from the guide vanes 15. In Fig. 5 the inlet guide vanes are formed with longitudinal chambers adjacent the leading and trailing edges, a duct 43 being disposed within the leading edge chamber, cooling air supplied into the duct impinging against the inward surface of the leading edge before discharging from the vane. Cooling air discharging from tubes 47 against the outer surface of the shroud 22 discharges from the chamber 42 into the trailing edge chambers 45 of the guide vanes discharging therefrom through orifices 48 formed in the trailing edge 46.