Thrust reverser for by-pass gas turbine engine
AssigneeRolls-Royce (1971) Limited
InventorsLeslie Richard Harper, William James Lewis, David Roberts McMurtry, Lance Peter Bell, John Matthew Hall
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Abstract
A by-pass gas turbine engine capable of producing an unmixed exhaust stream which comprises a core of hot turbine exhaust gases surrounded by an annular layer of by-pass air, is combined with a target thrust reverser. The ratio of the total pressure of the by-pass air to the total pressure of the turbine exhaust gases is arranged to be greater than unity to a significant extent, and the buckets are made from lightweight materials such as titanium, light alloys or even fiber re-inforced composite materials.
Claims9
In the combination of a bypass gas turbine engine with a thrust reverser wherein said gas turbine engine comprises
- a core engine containing a casing and a nozzle, the end of said nozzle defining a first exit plane through which a relatively hot exhaust gas produced by said core engine flows,
- a bypass casing surrounding said core engine and defining with said core engine casing an annular bypass flow passage which terminates in a second nozzle, the end of said second nozzle defining a second exit plane located in the region of said first exit plane through which a relatively cooler bypass air produced by a compressor means flows,
- said core engine, bypass casing and compressor means cooperating to produce a substantially unmixed exhaust gas stream in which a cylindrical sheath of said relatively cool bypass air surrounds a core of said relatively hot exhaust gas and in which the total pressure of said relatively cool bypass air is greater than the total pressure of said relatively hot exhaust gas, and wherein said thrust reverser comprises
- a flow deflecting surface for altering the direction of flow of said unmixed exhaust gas, and
- means for deploying said flow deflecting surface to a position downstream of said gas turbine engine to intercept said unmixed exhaust gas, the improvement wherein
- said core engine, bypass casing and compressor means produce a total pressure of said relatively cooler bypass air which exceeds the total pressure of said relatively hot exhaust gas to a sufficient extent that said relatively cooler bypass air forms a relatively cooler barrier layer over said flow deflecting surface when said flow deflecting surface is deployed, said barrier layer serving to isolate said flow deflecting surface from said hot exhaust gas, said flow deflecting surface being made predominantly of a material which has a safe working temperature which is lower than the temperature of said relatively hot exhaust gas existing at the time said flow deflecting surface is deployed.
Dependencies are inferred from the claim text.