Patent Application
20170167437
This application claims the benefit of the French patent application No. 1562341 filed on Dec. 15, 2015, the entire disclosures of which are incorporated herein by way of reference.
The present invention concerns the field of jet engines and the arrangement thereof in the rear section of an aircraft. The present invention relates to a novel type of jet engine, to the rear section of the aircraft bearing the jet engines, to the method for producing the rear section, and to the aircraft having such a rear section. It applies more particularly to commercial airplanes.
The present invention relates to aircraft equipped with two jet engines, also referred to as turbofans, that are fitted in the rear section of the fuselage on either side of the fuselage.
The rear section of the fuselage comprises a section of variable cross section that bears the empennage and is situated at the rear of the aircraft at the opposite end from the cockpit in a configuration of the conventional type.
The application EP 11382409.8, filed by the present applicant on Dec. 28, 2011, describes an aircraft in which two engines are arranged at the rear on either side of the fuselage.
However, because they are partially buried, the distance between them decreases. As a result, the risk of being impacted by an event of the UERF (Uncontained Engine Rotor Failure) type increases. An event of the UERF type is characterized by the detachment of an internal part of the jet engine, which will directly or indirectly strike the fuselage or the opposite engine. A solution for avoiding this that has been proposed by the present applicant in another patent application comprises providing an internal shield positioned in a vertical plane of symmetry of the fuselage.
However, the addition of a shield having a sufficiently solid structure increases the weight of the airplane. It also makes it necessary, given its bulk, to revise the internal organization of the tail of the airplane so as to allow it to be fitted.
The applications WO2014/074149 and US2014/025216 describe an air intake zone and an exhaust zone, the axis of the air intake zone not being coincident with the axis of the exhaust zone. In the application WO2014/074149, the air intake zone corresponds to a simple opening in the fuselage of the airplane. In the application US2014/0252161, the two parts of the engine of non-coincident axes are connected by a shaft which drives propellers located on the axis of the exhaust zone.
The aim of the present invention is to propose a novel type of jet engine providing an alternative that makes it possible to increase the ingestion of the boundary layer and thus the performance of the engine, while remedying the problem of UERF or any equivalent problem without resorting to fitting a shield.
To this end, the present invention proposes a jet engine comprising at least three zones including an air intake zone and an exhaust zone, wherein the axis of the air intake zone is not coincident with the axis of the exhaust zone of the engine, the engine as a result having at least two intersecting axes and being referred to as a multiaxial engine.
Thus, the jet engine has at least two parts with different longitudinal orientations: by choosing the orientation of the zones of the engine that are more sensitive to the detachment or breakage of elements of the gas generator, this makes it possible to also choose the direction of the possible paths of these detached elements. Thus, when the engine is positioned on the rear section of an aircraft in the region of its variable cross section, a suitable orientation having been chosen for certain zones of the engine, the direction of the paths of the detached elements does not meet the engine disposed on the other side of the rear section of the fuselage.
The jet engine has at least one of the following optional features, considered in isolation or in combination.
The axis of the air intake zone and the axis of the exhaust zone are parallel.
The jet engine comprises a driving zone; the axis of the driving zone is neither parallel to nor coincident with the axes of the air intake zone and of the exhaust zone, the engine thus having three different axes.
The jet engine comprises a compression zone and a combustion zone; the axes of the driving zone, of the compression zone and of the combustion zone are coincident.
The present invention also relates to an aircraft rear section having a fuselage section of variable cross section comprising at least two jet engines positioned on either side of the section and comprising at least three zones including an air intake zone and an exhaust zone, the axis of the air intake zone not being coincident with the axis of the exhaust zone of the engine, the engine as a result having at least two intersecting axes and being referred to as a multiaxial engine, wherein the axis/axes of further zones of the multiaxial jet engine is/are oriented such that one or more surface(s) delineating trajectories of detached elements of each jet engine do(es) not meet the opposite jet engine.
The aircraft rear section has at least one of the following optional features, considered in isolation or in combination.
The surface comprises a cone representative of a UERF event that is established for a driving zone of the engine.
The shape of the fuselage and/or the shape and position of the various means for securing the jet engines to the fuselage are determined so as to allow the zone(s) contained between the air intake zone and the exhaust zone of the motors to follow the contour of the fuselage and to orient the delineating surface(s).
The exhaust zone of the engine and the exhaust zone of the other engine are merged so as to form only one exhaust zone positioned at the rear end of the section.
The exhaust zone is provided with a thrust reverser system.
The present invention also relates to the aircraft provided with such a rear section.
The present invention also relates to a method for producing an aircraft rear section having a variable cross section, bearing at least two jet engines comprising at least three zones including an air intake zone and an exhaust zone, the axis of the air intake zone not being coincident with the axis of the exhaust zone of the engine, the engine as a result having at least two intersecting axes and being referred to as a multiaxial engine, wherein the method comprises a step in which the engines are positioned on either side of the variable section such that one or more surface(s) delineating trajectories of detached elements of each jet engine do(es) not meet the opposite jet engine.
The method comprises a step in which the orientation of the axes of the multiaxial engines is chosen and the shape of the fuselage and/or the shape and position of the various means for securing the jet engines to the fuselage is/are modified in order to make it possible to orient the delineating surface(s) and the engines with respect to the contour of the fuselage.
Further aims, advantages and features of the invention will become apparent from reading the following description of the jet engine and of the rear section of an aircraft provided with such an engine according to the invention, given by way of nonlimiting example with reference to the appended drawings, in which:
As shown in
Throughout the following description, by convention, the direction X-X corresponds to the longitudinal direction of the aircraft, which is akin to the longitudinal direction of the rear section 2 thereof.
Moreover, the terms “front” and “rear” should be considered with respect to a direction of forward travel of the aircraft encountered as a result of the thrust exerted by the jet engines 1, this direction being represented schematically by the arrow 4.
The jet engine 1 has at least five zones:
an air intake zone 6 comprising an air intake 8 which orients the penetration of air into the engine, represented by the arrows 10, and in which a propeller 12, referred to as a fan, for drawing in air is housed;
a compression zone 14 provided with a compressor 16 for progressively increasing the pressure of the air drawn in;
a combustion zone 18 including a combustion chamber 20 in which the fuel is injected into the compressed air, causing the combustion thereof and the violent rearward ejection of hot gases, represented by the arrows 22;
a driving zone 24 comprising a turbine 26 that is driven by the ejection 22 of hot gases and in turn allows the propeller 12 and the compressor 16, to which the turbine is linked by a shaft 28, to be set in motion;
an exhaust zone 30 having an exhaust nozzle 32 that regulates the outlet of the gases 22 providing the thrust for moving the aircraft forward, represented by the arrow 4.
In the rest of the description, an axis of a zone will be considered to be the longitudinal central axis of partial or full symmetry of the components or of a part of the components of this zone. If a zone happens not to have any components having an axis of partial or total central symmetry, the axis of an adjacent zone will be considered.
Thus, for example, the axis A-A of the air intake zone 6 in the examples illustrated in
The axis B-B of the compression zone 14 is formed by the axis of the compressor 16 and more specifically the axis of rotation of the vanes 38 (blade or the like) that it bears.
The axis C-C of the combustion zone 18 is the axis of longitudinal symmetry of the combustion chamber 20. When the chamber has a shape without a central longitudinal axis of symmetry, the axis of the combustion chamber is the axis of the compression zone 14 and/or of the driving zone 24.
The axis D-D of the driving zone 24 is formed by the axis of the turbine 26 and more specifically by the axis of the blades 40 of the turbine 26.
The axis E-E of the exhaust zone 30 is formed by the axis of the outlet of the nozzle 32.
In motors of known type, the axes A-A of the air intake zone, B-B of the compression zone, C-C of the combustion zone, D-D of the driving zone and E-E of the exhaust zone are all coincident along one and the same axis F-F, as shown in
In order to afford a novel configuration engine that makes it possible to address the problem set out above, the axis of the air inlet zone 6 is not coincident with the axis of the exhaust zone 30. As a result, if the axes of these end zones are not coincident, it follows that there is at least one zone in which the axis intersects at least one of the axes of the end zones in order to be connected up. As a result, the jet engine is therefore multiaxial since the various zones of which it is made up have at least two different non-coincident axes which intersect one another. The jet engine 1 does not have an elongate shape centered on a single axis (F-F in the prior art illustrated). The various components of the jet engine are not centered on one and the same axis. The axis of one or more zones is different than the axis of one or more other zones. The engine has at least two zones that are oriented in a different longitudinal direction.
The engine has zones at which elements can break or detach given, for example, the vibrations or other thermomechanical effects produced in these zones during operation of the engine. Thus, for example, the rotational movement of the turbine of a very high speed engine can cause the detachment by breakage or unsticking or the like, of elements, pieces, debris or the like, these being referred to as detached elements in the following text. The analysis of these zones leads to the identification of the paths followed by these detached elements. Thus, for the turbine of a jet engine, for example, it is known that the detached elements are contained in a geometric surface having a conical shape known as a cone. The surface could have any other shape and will be referred to in a general manner in the following text as a surface delineating the paths of detached elements.
According to one embodiment, such as those illustrated in
The present invention relates to the field of aircraft of which the rear section 2 has a variable cross section. The rear section 2 of the aircraft according to the invention that is shown schematically in
In all of the configurations illustrated in
As shown in
One or more zones of the jet engine corresponding to the sensitive zone(s) of the engine are positioned along one or more axes making it possible to orient the delineating surface(s) such that they do not meet the opposite jet engine.
It is also possible to modify other parameters, such as the shape of the fuselage and more specifically the curvature of the variable cross section or the shape, and notably the length, of the various means for securing the jet engine to the fuselage or the positions thereof thereon.
According to the embodiments shown on
In this way, the air intake zone 6 is substantially parallel to the axis X-X of the rear section 2 and can be positioned closest thereto in order to increase the ingestion of the boundary layer.
As shown in
In the present invention, as shown in
The shape of the cone 41 representative of a UERF event depends on the jet engine 1. Depending on the shape of the cone, the axis of the driving zone 24 of the corresponding jet engine 1 or 1′ is determined such that the cone does not meet the other jet engine 1′ or 1, respectively, and is thus positioned entirely upstream of the jet engine. It is also possible, as seen above, to modify other parameters such as the shape of the rear section, like the curvature of the variable cross section 42 of the fuselage, or the shape, and notably the length, of the various means 43, 43′, 44, 45, 44′, 45′ for securing the jet engine to the fuselage or the positions thereof thereon. All of these parameters are chosen so as to make it possible to position the cone as desired while positioning the jet engine along the rear section of variable cross section.
In all of the embodiments illustrated in
The first fastener allows the driving zone 24 of the jet engine 1, 1′ to be directly secured, by way of a link 43, 43′, to the rear section 42 of variable cross section of the fuselage. The fasteners 43, 43′ are connected by a link rod 46 passing through the inside of the rear section 42 of variable cross section of the fuselage.
The second fastener allows the compression zone 14 of the jet engine 1, 1′ to be secured by way of a link rod 44, 44′ to the rear section 42 of variable cross section of the fuselage.
The third fastener allows the air intake zone 6 of the jet engine 1, 1′ to be secured by way of a link rod 45, 45′ to the rear section 42 of variable cross section of the fuselage.
In the embodiment in
The second fastener can be removed: it makes it possible to strengthen the retention of the jet engine.
The additional and distinctive features of the embodiments of
the exhaust zones 30 of the jet engines 1, 1′ are merged to form only one: the exhaust zone is thus positioned at the rear end of the rear section on the axis X-X thereof. The axis E-E of the exhaust zone 30 is coincident with the axis X-X of the rear section.
This makes it possible to have only one nozzle rather than two. This results in a saving of weight, of bulk, of manufacturing cost, maintenance, etc.
In the embodiment of
While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1562341 | Dec 2015 | FR | national |
