| 摘要 |
<p>910,178. Gas-turbine jet engines. ROLLS-ROYCE Ltd. July 26, 1961 [Aug. 2, 1960], No. 26778/60. Class 110 (3). A gas-turbine jet engine of the by-pass type comprises a jet pipe, reheat combustion equipment mounted within the jet pipe, a by-pass passage disposed around the jet pipe, a valve controlling flow of by-pass air from the bypass passage, ducting disposed on the downstream side of the valve and through which the by-pass air may flow into the jet pipe for mixing therein with the turbine exhaust gases, and means for moving the valve between at least two positions in the first of which at least the greater part of the by-pass air flows through the ducting and into the jet pipe and in the second of which it is prevented from so doing. In the engine shown, reheat fuel ring manifolds 20 and annular flame stabilizing troughs 22 are disposed within the jet pipe 15 and an annular by-passage passage 16 is disposed outside the jet pipe, a series of angularly spaced apart ducts 23 being disposed at the downstream end of the by-pass passage, the ducts 23 being shaped as shown in Fig. 6, and by-pass air passing therethrough to mix with the turbine exhaust gases in the jet pipe. The spaces between ducts 23 are closed at the downstream ends so as to allow by-pass air to discharge through the annular space 24<SP>1</SP> outside the jet nozzle. A ring valve 26 is disposed at the upstream end of the ducts 23 and is formed with apertures 28, angular movement of the valve causing the apertures 28 to move into alignment with the ducts 23 or with the spaces therebetween. The ring valve is provided with tapering baffles 27 at its upstream face which guide the by-pass air to the apertures 28. The ring valve is rotated by means of a motor 32 and pinion 30 controlled by lever 41. When reheat is not in use the ring valve is disposed so that the apertures 28 therein are aligned with ducts 23 whereby by-pass air passes through the ducts to mix with the turbine exhaust gases in the jet pipe. When reheat is in operation, the ring valve is disposed so that the ducts 23 are blanked off and the by-pass air then passes through the spaces between the ducts 23 and discharges through the annular passage 24. A portion of the by-pass air passes through the annular spaces 33, 35 and duct 36 to the inner surface of the jet nozzle 37 for cooling purposes. A variable area nozzle having pivoted flaps 37 is indicated but this feature is not essential to the invention.</p> |
