GB870854A - Axial flow compressors - Google Patents

Abstract

870,854. Axial-flow compressors; gas-turbine jet-propulsion plant. NAPIER & SON Ltd., D. May 28, 1958 [July 3, 1957], No. 21207/57. Classes 110 (1) and 110 (3). In a multi-stage axial-flow compressor including at least two rows of rotor blades 25, 26, Fig. 2, and at least two rows of stator blades 103, 39, respectively downstream thereof, the blades 39 are adjustable about substantially radial axes into one or other of two operating positions, in one of which they operate with maximum efficiency as normal stator blades, while the other position gives the maximum effective throat area between the blades. The compressor supplies air through a duct 16, Figs. 1A, 1B, to the main combustion chamber 17 of a jet-propulsion engine. The compressor is driven by a turbine 30 energized by a rocket system comprising catalytic decomposition chambers 31 in which hydrogen peroxide is decomposed to form oxygen-rich steam, some of the oxygen being used for combustion of paraffin in combustion chambers 32. The turbine exhaust passes through ducts 33 into the main air stream. At a sufficiently high speed, as sensed by a Mach meter 34, the engine is changed over from turbo-rocket to ram-jet operation. This is effected by shutting off the fuel supply to the rocket system, either manually or automatically. At the same time, an hydraulic servomotor 38 automatically turns the stator blades into the position of maximum throat area and moves flap valves 36 into the chain-dotted position to open a by-pass passage 35 around the compressor. The means for automatically operating the servomotor 38 may be responsive to the rotational speed of the turbine 30. During ram-jet operation, the compressor windmills in the air stream, a freewheel 28 permitting it to overrun the turbine. A desired shock pattern at the intake is maintained by means of a spill port controlled by flaps 44. Flaps 41 are closed during ram-jet operation but are opened during turbo-rocket operation to provide an additional air intake. The area of the jet nozzle can be adjusted by means of an axially movable bullet 20 which is connected to its operating ram 21 by means of a shaft 22 extending through the centre of the engine. Reference has been directed by the Comptroller to Specification 837,497.