GB1120240A - Air intake duct for a gas turbine engine - Google Patents

Abstract

1,120,240. Gas turbine engine air intakes. ROLLS-ROYCE Ltd. April 19, 1967 [April 26, 1966], No. 18312/66. Heading F1G. An air intake duct for a gas turbine engine comprises an upstream part which may be moved between a first position in which a gap is formed in the upper part of the air intake duct and a second position in which the gap is closed, there also being means for opening and closing the upstream part to air flow therethrough. The gas turbine engine shown is disposed within a pod 14 which comprises a fixed downstream part 15 and an axially-movable upstream part 16. The upstream part 16 may be moved axially from the position shown in Fig. 1 to the position shown in Fig. 2 in which an annular gap 20 is formed between the parts 15, 16. The axial movement is produced by means of the piston and cylinder actuator 22, 21. A pair of clamshell doors 23 pivotally mounted at 24 is provided, the doors being in the open position in the disposition shown in Fig. 1 but being moved to the closed position in the disposition shown in Fig. 2 so that the air intake to the engine is then through the annular tap 20. A pair of part-cylindrical shield members 25 is pivotally mounted at 26, the members lying in the recesses 27 in the disposition shown in Fig. 1 but moving to an open position in the disposition shown in Fig. 2, see also Fig. 3 so that the members 25 act as a baffle and prevent noise from the engine intake passing downwardly through the lower part of the annular gap 20. In a second embodiment the upstream portion of the intake structure is pivotally mounted on the downstream portion at the lowermost point. When the upstream portion is moved about the pivotal point an air inlet gap is formed at the upper part of the air intake structure. A pair of clamshell doors is provided in the upstream portion but the silencer baffle members are not required.