Cycle gas turbine engine
AssigneeROLLS-ROYCE plc
InventorsRichard J Flatman, Christopher Freeman
Life of this patent
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Abstract
A variable cycle gas turbine engine (10) includes first and second compressors (18,16), combustion apparatus (20) and first and second turbines (22,24) operable to drive the first and second compressors (18,16) respectively via interconnecting shafts. The capacity of one of the turbines (24) may be varied, for example by means of guide vanes (32) which can be adjusted to reduce or increase a throat area (40) through which air leaves the guide vanes to impact the turbine. The capacity of the turbine may be increased at low engine speeds, to reduce the pressure ratio across the turbine and across the compressor (16) which it drives, thereby improving the surge margin of the compressor.
Claims9
A variable cycle gas turbine engine including first and second compressors, combustion apparatus and first and second turbines, the first and second turbines being operable to drive the first and second compressors respectively via interconnecting shafts, characterized in that means for bleeding air from at least one compressor and feeding such air between a downstream region of the first turbine and a first part of the second turbine, thereby to vary the capacity of the first turbine, so that in use, for a given engine power requirement the variation of the first turbine results in a corresponding variation in the capacity of the first turbine thereby preventing the first compressor from surging.
A variable cycle gas turbine engine including first and second compressors, combustion apparatus and first and second turbines, the first and second turbines are operable to drive the first and second compressors respectively via interconnecting shafts, characterized in that means are included for varying the capacity of the second turbine, so that in use, for a given engine power requirement the variation of the second turbine results in a corresponding variation in the capacity of the first turbine thereby preventing the second compressor from surging including means for bleeding air from at least one compressor and feeding such air into a region downstream of and in fluid communication with the second turbine, thereby to vary the capacity of the second turbine, the stator vane downstream of the second turbine being hollow and including a plurality of orifices passing through a wall thereof, and means being provided for passing air into the inside of the stator vane to allow ejection of the air through the orifices to a region downstream of the second turbine.
Dependencies are inferred from the claim text.