Patent Application
20140053533
This application relates to the inclusion of a thrust reverser at a rear end of a gas turbine engine which utilizes a reverse flow concept.
Gas turbine engines are known, and typically include a fan delivering air into a compressor section and also outwardly of the compressor as bypass air. Air from the compressor section passes into a combustor, is mixed with fuel, and ignited. Products of this combustion pass downstream over turbine rotors, driving them to rotate.
One recently developed type of gas turbine engine is a so-called “reverse flow” gas turbine engine. In typical gas turbine engines, the fan is positioned axially at an end of an engine, and then the compressor, combustor and turbine section are placed in that order. In a reverse flow gas turbine engine, the turbine is adjacent the fan, and the combustor is at an inner end of the turbine, with the compressor positioned even more inwardly.
A thrust reverser is utilized once an aircraft carrying the gas turbine engine has landed, and acts to create a reverse force to slow the aircraft.
One concept that has been proposed in gas turbine engines is a thrust reverser provided by pivoting shell halves at the rear of a nozzle. Such thrust reversers were generally utilized in prior gas turbine engines which used little, or no, bypass air.
In addition, various types of thrust reversers have been incorporated into more modern gas turbine engines which do have a large fan providing bypass air as propulsion, and in addition to the air passing through the compressor. However, this standard type of gas turbine engine generally had an engine core that extended beyond the end of the nozzle, such that the shell halves could not pivot inwardly to a thrust reverse position.
In a featured embodiment, a gas turbine engine has an outer housing defining an exit nozzle at a downstream end of the engine. A fan, mounted at an upstream end of the engine, rotates on a first axis. The nozzle is centered on the first axis. A core engine has a compressor section, a combustor and a turbine section. The turbine section is closest to the fan. The combustor section and then the compressor section are positioned further away from the fan relative to the turbine section. A downstream end of the nozzle has at least one pivoting shell and an actuator to pivot the at least one shell between an in-flight position and a deployed position in which the at least one shell inhibits a flow cross-sectional area of the nozzle to provide a thrust reverser.
In another embodiment according to the previous embodiment, the core engine is positioned on a second axis. The first axis and second axis are non-parallel.
In another embodiment according to any of the previous embodiments, there is a pair of pivoting shells.
In another embodiment according to any of the previous embodiments, each of the shells are driven by a linkage to move between the in-flight flight position, and the deployed position at which a reverse thrust is created.
In another embodiment according to any of the previous embodiments, the linkages are mounted within fixed portions of the nozzle, which are circumferentially intermediate the pivoting halves.
In another embodiment according to any of the previous embodiments, the fixed portions of the nozzle include a downstream end of the shells.
In another embodiment according to any of the previous embodiments, a downstream end of the shell has a curved surface that is received within a mating curved surface in the downstream end of the fixed portions of the nozzle.
In another embodiment according to any of the previous embodiments, the fan delivers air into the compressor section, but also delivers bypass air to the nozzle.
In another embodiment according to any of the previous embodiments, the fan delivers air into the compressor section, but also delivers bypass air to the nozzle.
In another embodiment according to any of the previous embodiments, the core engine is positioned on a second axis. The first axis and second axis are non-parallel.
In another embodiment according to any of the previous embodiments, each of the shells is driven by a linkage to move between the in-flight flight position, and the deployed position at which a reverse thrust is created.
In another embodiment according to any of the previous embodiments, the linkages are mounted within fixed portions of the nozzle, which are circumferentially intermediate the pivoting halves.
In another embodiment according to any of the previous embodiments, the fixed portions of the nozzle include a downstream end of the shells.
In another embodiment according to any of the previous embodiments, a downstream end of the shell has a curved surface that is received within a mating curved surface in the downstream end of the fixed portions of the nozzle.
In another embodiment according to any of the previous embodiments, the gas turbine engine further includes a fan drive turbine positioned downstream of the turbine section of the core engine and a gear reduction. The gear reduction is included between the fan drive turbine and the fan. The fan rotates at a slower speed than the fan drive turbine.
In another embodiment according to any of the previous embodiments, the core engine turbine section and the fan drive turbine are separate turbines.
In another embodiment according to any of the previous embodiments, the fan drive turbine rotates on the first axis.
In another embodiment according to any of the previous embodiments, the core engine is positioned on a second axis. The first axis and second axis are non-parallel.
In another featured embodiment, an aircraft has a gas turbine engine which includes an outer housing defining an exit nozzle at a downstream end of the engine. A fan mounted at an upstream end of the engine, rotates on a first axis. The nozzle is centered on the first axis. A core engine has a compressor section, a combustor and a turbine section, with the turbine section being closest to the fan. The combustor section and then the compressor section are positioned further away from the fan relative to the turbine section. A downstream end of the nozzle has at least one pivoting shell and an actuator to pivot the at least one shell between an in-flight position and a deployed position in which the at least one shell inhibits a flow cross-sectional area of the nozzle to provide a thrust reverser.
In another embodiment according to the previous embodiment, the core engine is positioned on a second axis. The first axis and second axis are non-parallel.
In another embodiment according to any of the previous embodiments, there is a pair of pivoting shells.
In another embodiment according to any of the previous embodiments, each of the shells are driven by a linkage to move between the in-flight flight position, and the deployed position at which a reverse thrust is created.
In another embodiment according to any of the previous embodiments, the fan delivers air into the compressor section, but also delivers bypass air to the nozzle.
In another embodiment according to any of the previous embodiments, the he aircraft further has a fan drive turbine positioned downstream of the turbine section of the core engine, and a gear reduction. The gear reduction is included between the fan drive turbine and the fan. The fan rotates at a slower speed than the fan drive turbine.
In another embodiment according to any of the previous embodiments, the core engine is positioned on a second axis. The first axis and second axis are non-parallel.
These and other features of this application will be best understood from the following specification and drawings, the following of which is a brief description.
As shown, a nozzle 23 has shell halves 26 that can pivot, as will be explained below, to block the flow out of an exhaust exit area 24 of the engine 22.
A core engine 400 includes combustion section 36 positioned between another turbine section 138 and a compressor section 34. Air passes into an inlet duct 32 to be delivered to the compressor 34. The duct 32 is over a limited circumferential extent. At other circumferential locations, air flows as bypass air for propulsion. The air is compressed and delivered into combustion section 36, where it mixes with fuel and is ignited. Products of this combustion pass over turbine section 138, which drives compressor section 34. The products of combustion then pass over turbine section 38, to drive the fan.
The illustrated jet engine is a “reverse flow engine” in that the compressor is positioned further into the engine than is the turbine 38.
As shown in
In an engine that is reverse flow, and in particular in one wherein the axes X and Y are not parallel, a relatively long core engine 34/36/138 can be achieved without the core engine blocking the exit area 24. Thus, with this engine arrangement, a thrust reverser utilizing the shell halves 26 can be incorporated.
Once an aircraft associated with the engine 22 has landed, the actuator 62 drives the linkage 60 into a deployed position 60′ in which the shell halves 26 are pivoted to a deployed position (
Although an embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.
