| 摘要 |
1493049 Gas turbine ducted fan engines GENERAL ELECTRIC CO 10 Feb 1975 [25 Feb 1974] 5589/75 Heading F1J The invention relates to a gas turbine ducted fan engine which comprises a first fan and a second fan also a first fan or by-pass duct and a second fan or by-pass duct. The engine shown in Fig. 1 comprises a first fan 34, a second fan 40, a core engine comprising a compressor 24, combustion equipment 26, a first turbine 80 which drives the compressor 24 through shaft 82, a second turbine 90 which drives the second fan 40 through shaft 94, and a third turbine 102, 104 which drives the first fan 34 through shaft 110. The engine also comprises a core engine casing 49, an intermediate casing 51 which defines with the core engine casing a first fan duct 48, and an outer casing 12 which defines with the intermediate casing a second fan duct 52. The rotor blades of the first and second fans 34 and 40 are of variable pitch. The stator blades 36, 38 of the first fan, the stator blades 42 of the second fan are also of variable pitch and the first three rows of stator blades 60, 62, 64 of the compressor are of variable pitch. The inlet guide vanes 75 of the compressor-drive turbine 80 are of variable pitch as are the inlet guide vanes 92 of the fan-drive turbine 90 and the inlet guide vanes 106 of the fan-drive turbine 102, 104. The air inlets 56 and 50 to the core engine and first fan duct 48 are downstream of the second fan 40; the air inlet 54 to the second fan duct 52 is downstream of the first fan. Combustion equipment 119 is disposed in the first fan duct 48 and has associated therewith retractable flame stabilizing equipment 120. The core engine flow duct, the first fan duct and the second fan duct terminate in annular discharge nozzles 116, 118, 126, flaps 122 being pivotally mounted on the intermediate casing 51, the flaps being positioned as shown in Fig. 1 for subsonic operation the flaps defining a convergent nozzle 118 at the outlet of the first fan duct; in Fig. 2 the flaps 122 are pivoted outwardly to close off the outer fan duct and to provide a convergent-divergent nozzle outlet to the inner fan duct; the flame-holder 120 is in the operative position and the duct burner 119 is operative; this is the mode for supersonic operation. In Fig. 3 the core engine, the inner fan duct and the outer fan duct discharge into a common nozzle 150 defined by variable flaps 164. The flaps 164 also the flaps 166 are pivoted outwardly, Fig. 4, (not shown) for supersonic operation, flow through the outer fan duct being thereby closed off. In Fig. 5, (not shown) the single fan-drive turbine 212, 214, 216 drives both the first fan 184 and the second fan 190 through shaft 192. |
