| 摘要 |
<p>A bleed apparatus (34) for a gas turbine engine (10) is positioned in the duct (16) between a low pressure compressor (14) and an intermediate pressure compressor (18). The bleed apparatus (34) comprises a plurality of circumferentially spaced bleed apertures (38) and a plurality of pivoted (42) bleed doors (40) which move between a fully open position and a fully closed position. Each bleed door (40) has an independent actuator (44,46) and the actuators (44,46) operate to fully close or open the bleed doors (40) in unison. Each actuator (44,46) comprises a hydraulically operated piston (46) and a cylinder (44) which ensures uniform closing and sealing and the remaining bleed doors (40) operate if one seizes. The bleed apertures (38) have radially extending side walls (72,74) which control the bleed air. The first and second walls (72,74) prevent the bleed air flowing circumferentially from the bleed aperture (38) until the bleed doors (40) have opened a predetermined amount to provide a continuously increasing bleed area as the bleed doors (40) move towards the fully open position.</p> |
