GB773499A - Improvements in or relating to axial-flow compressors and to gas-turbine engines incorporating such compressors - Google Patents

Abstract

773,499. Axial-flow compressors; gas turbine plant. ROLLS-ROYCE, Ltd. Jan. 27, 1955 [Feb. 12, 1954], No. 4273/54. Classes 110 (1) and 110 (3). A multi-stage axial-flow compressor comprises a lowpressure rotor having at least two rows of rotor blades 13, 14 which are designed for subsonic velocities (Mach No. less than 0.9) or transonic velocities (Mach No. between 0.9 and 1.25), a row of stator blades 15 between each pair of said rows of rotor blades, and a high-pressure rotor having at least one row or rotor blades 21 which are designed for supersonic velocities (Mach No. greater than 1.25) and receive air directly from the downstream low-pressure rotor blade row, the low-pressure and high-pressure rotors being arranged to rotate in opposite directions, and the outlet angle of the rotor blades 14 of the downstream low-pressure rotor blade row being so chosen that the velocity of the air relative to the rotor blades 21 is supersonic. The velocity of the air at the outlet from the blades 14 may be axial in direction or may have a whirl component in the direction of rotation of the low-pressure rotor. The rotor blades 21 are followed by stator blades 23, a further row of rotor blades 22 and outlet guide vanes 27. The compressor forms part of a gas turbine engine comprising combustion equipment 11 and oppositelyrotating turbine rotors 17, 25 which drive the low-pressure and high-pressure compressor rotors respectively through hollow shafts 16, 24. Shaft bearings 30, 31, 32, 33 are supported by stator blades 15, 23, 28. Specification 707,298 is referred to.