GB1224879A - Improvements in or relating to gas turbine engines - Google Patents

Abstract

1,224,879. Deflecting propulsive gases. ROLLS-ROYCE Ltd. 30 May, 1968 [17 June, 1967], No. 28031/67. Heading B7G. Movable deflecting means in a propulsion nozzle of a gas turbine engine either allow passage of propulsion gases rearward through the nozzle or direct the gases outwardly through one or more ducts in the wall of the nozzle; further deflecting means, mounted in or adjacent to the or each duct, being movable to give a component of thrust in a forward or rearward or intermediate direction. Two eyelid flaps are mounted in the propulsion nozzle 18, so that in position 24 the rearward flow of gases is unimpeded, while in position 26 the gases are caused to flow through ducts 20 in the wall of the nozzle 18. At the outer end of each duct are cascades 28, in the form of vanes 30 in a frame, the vanes in the forward half of the frame being inclined so as to direct the gases forward, while the rear vanes are inclined so as to direct the gases rearward. The cascades may be moved fore-and-aft by air motors 32 and screws 34, so that varying degrees of forward or rearward thrust may be obtained. In a further embodiment, Fig. 4 (not shown), fixed deflecting vanes are used, the direction of thrust depending on whether the forward or rearward facing vanes are exposed by a visor (38). In a further embodiment, Fig. 5 (not shown), the mouth of each duct is shaped so that when the forward portions of the duct are exposed by a pivoted visor (42) the gases flow forward, while exposure of the rear facing parts of the duct mouth causes gases to flow rearward. In a further embodiment, Fig. 6 (not shown), faired flaps, pivoted at the outer end of each duct, are used in place of vanes, the direction of thrust depending on the orientation of each flap relative to the flow of gases along its duct.