EP3161271A1

EP3161271A1 - Chevron nozzle

Info

Publication number: EP3161271A1
Application number: EP15771007.0A
Authority: EP
Inventors: Rudolf Ganz
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-06-30
Filing date: 2015-06-26
Publication date: 2017-05-03
Also published as: WO2016000673A1; US20170130672A1; DE102015008204A1

Abstract

The invention relates to a chevron nozzle (13, 14, 21, 22, 30) for an engine (10, 12) of an aircraft (11), comprising at least one nozzle ring (31) and chevrons (32) arranged on the nozzle ring (31). The aim of the invention is to further save fuel and further reduce sound emissions. For this purpose, the nozzle ring (31) together with the chevrons (32) is designed so as to be freely rotating with at least one rotational speed such that a position of the chevrons (32) can be continuously varied.

Description

Cheyrondüse

description

Technical Field The invention relates to a chevron nozzle according to the preamble of claim 1.

Such Chevron nozzles are used in aviation or in modern passenger aircraft, for example the Dreamliner or the Boeing 787 or the Airbus A319.

Chevrons are sawtooth-shaped patterns on the exhaust nozzle of a jet engine. Chevron nozzles have practically teeth and gaps.

Chevrons have the advantage of reducing noise emissions. However, chevrons, according to Wikipedia, may have a minimal but undesirable thrust loss, e.g. 0.25%, result.

State of the art

A Chevrondüse is known from DE 69819441 12.

From WO 2008 045 090 A1 a Chevrondüse known in which two chevron nozzle elements relative to each other around a very limited angle are rotated against each other to change a geometry and to achieve an adaptation to different flight conditions. A

CONFIRMATION COPY rotatable, overlapping nozzle device alters the area and geometry of the flow path during certain flight conditions. These

Publication teaches how fuel savings can be achieved, closely related to various flight conditions such as cargo and takeoff.

Another Chevrondüse is known from WO 2007 122 368 A1. This print D2 describes as in a nozzle at the area

intervening gaps can be reduced. This nozzle should have improved performance and lower noise emissions. This is done by a specific adjustment of the tooth gaps. Large gaps and small gaps can be set.

The document EP 2 444 645 A2 shows an adjusting mechanism or

Control mechanism for a chevron nozzle.

OBJECT OF THE INVENTION The object of the invention is to provide a chevron nozzle of the generic type in which further fuel savings and a further reduction of noise emissions can be achieved.

Solution and advantages of the invention

This object is achieved by a device having the features specified in the characterizing part of claim 1 in conjunction with its generic features. The invention is based on the recognition that by constant rotation of the chevron teeth, vortices are reduced by constantly changing the position of the teeth. The rotation according to the invention thus reduces disturbances and turbulences in the exit region of the nozzle. The reduction of these turbulences or disturbing swirls ensures a fuel saving or an increase in the thrust force over known solutions.

The Chevrondüse invention with rotation is designed for gas turbines. The rotation may be free, thereby adapting to the vortices and / or aerodynamically directed and / or mechanically generating a specific rate of rotation and / or direction. Special openings in the engine mount and / or the housing may be arranged to allow rotational operation. The idea with this nozzle is to form a dense helix between inner and outer flow. This absorbs sound waves and efficiently damps exhaust noise. The rotation reduces upstream disturbances, stabilizing turbulent flows.

Another advantage of the rotation according to the invention is that chevrons can be made smaller, which, among other things, positively influences engine performance or enables higher thrust.

Due to the helix formed by the rotation of the air stream (core stream and side stream) have more surfaces contact with the surrounding air mass, whereby a higher thrust force is possible.

Therefore, such gas turbine engines with rotating exhaust nozzle for gas turbines are very beneficial.

Lower fuel consumption and lower noise emissions are important targets for commercial and equivalent commercial aircraft Aircraft engines. As a result, the turbofan engines described at the beginning have become popular. But even in the military area trying to avoid noise or noise, so that the inventive idea can also be applied there. These goals have been partially achieved by the introduction of chevrons. In principle, cold and hot air streams are mixed. This principle has been taken up in the inventive solution.

In the embodiment of the nozzle according to the invention, various patterns and shapes of the trailing edges or teeth of this nozzle drive can be taken into account. For example, a radius at the tooth tips or at the tooth gaps can be optimized. Also, the height of the teeth can be adjusted. These geometric changes can be adjusted to an adjusted rotational speed. Also, changes in tooth size are possible on the model of the prior art described.

With a nozzle according to claim 1, both a fuel saving and thrust increase as well as a reduction of noise emissions are achieved.

Advantageous embodiments of the invention and further advantages

Further advantageous embodiments of the invention are characterized in the subclaims.

In an advantageous development of the nozzle according to the invention it is provided that the nozzle ring is provided with a bearing which is attached to an engine part, in particular an engine cowling, an engine housing and / or a core shell part. The Bearing mounting allows a free rotation of the chevrorn ring. The rotation can be left or right.

Preferably, the bearing is a sliding bearing, such as a hydrodynamic bearing, a rolling bearing or a magnetic bearing. The slide bearing can be made relatively easy, which has a favorable effect on a moment of inertia and the engine mount. The rolling bearing is relatively low maintenance. A magnetic bearing has virtually no friction, so that fuel can be saved. Also conceivable are other bearings, such as ball bearings and the like.

In order to control a rotational speed of the chevron ring, it is expedient that the nozzle ring is driven by a motor drive. is. The drive can be electric motor and is thus easily controlled or regulated so that always an optimal rotational speed, depending on the flight mode is adjustable. A controlled rotation can thus be achieved by the use of motors.

Alternatively, the nozzle ring may have a free run, wherein the rotation by at least one drive element, in particular by lamellae takes place, which are aerodynamically driven by an engine jet Advantageously, the nozzle ring is independent of an additional motor drive. In this free mode, the rotation of the chevron ring in the direction and / or rotational speed can adjust to the exit flow. However, it may also be aerodynamically biased to rotate in a specific direction and / or rate.

The chevrons may be angular or rounded at the tips and / or depressions. In a further advantageous embodiment of the invention, the chevrons on the chevron tips and / or on the Chevron recesses, preferably in both places, a radius, in particular at least 2 cm, on. This reduces noise emissions.

The engine is preferably provided with an air intake, a fan, a compressor, a combustion chamber, a turbine, a discharge nozzle and a housing. Other engine designs such as turboprop engines are also conceivable.

A particularly preferred embodiment of the invention is characterized in that the engine is provided with an engine mount, wherein the engine mount has at least one recess or opening for at least one nozzle ring. In the recess or opening, the nozzle ring can rotate freely, wherein the engine housing and / or the engine cowling at the end of the nozzle is well fastened to a wing, so that a stable suspension is possible.

Since low noise emissions must be taken into account, especially in widebody aircraft, it is advantageous if the nozzle according to the invention is used in a turbofan engine, wherein the nozzle is used for a core flow and / or a sheath flow.

Because also in the military sector there is also the need to reduce noise emissions, it is favorable if the nozzle according to the invention is used in a jet engine.

Exemplary embodiments are explained in more detail with reference to the drawings, wherein Further advantageous developments of the invention and advantages thereof are described.

Show it:

Fig. 1 is a perspective view of a turbofan engine with two nozzles according to the invention, wherein the engine is arranged on an aircraft by an engine mount and provided with a housing, and wherein a first chevron rotary nozzle for a core stream and a second nozzle for a side stream is provided.

Fig. 2 is a perspective view of a jet engine with a chevron-rotation nozzle according to the invention, Fig. 3 is a perspective view of a nozzle ring of

Chevron rotary nozzle, according to FIG. 1 or FIG. 2 for use in engines with gas turbines, and

Fig. 4 is a schematic representation of an engine with the invention Chevrondüse.

Figures 1 to 4 illustrate chevron rotating nozzle 20 for an engine 10 (Fig. 1) and 19 (Fig. 2) of an aircraft 1 1 (Fig. 1) comprising at least one nozzle ring 25 and arranged on the nozzle ring 25 chevrons 26th The aircraft 1 1 is shown only symbolically.

The nozzle ring 25 is designed to be freely rotatable together with the chevrons 26 (FIG. 3) with at least one rotational speed, so that a position of the chevrons 26 is constantly changeable. 1 illustrates use of the chevron nozzle in an engine 10 having an engine mount 12, wherein the engine mount has at least one recess or opening 15, 16 for at least one nozzle ring 25.

More specifically, there are two Chevron nozzles 13, 14 provided in a turbofan engine 10, wherein the first nozzle 13 is used for a core stream and the second nozzle 14 for a jacket stream. By the engine mount 12, the engine 10 is fixed or mounted in a known manner on a wing of the aircraft 11. Thus, the engine 10 includes a core flow chevron orifice 13 and a shroud chevron rotation nozzle 14. Known suspensions would prevent rotation of the core flow chevron rotating nozzle 13 and the shroud chevron rotating nozzle 14. Therefore, the engine mount 12 for the inventive nozzles 13, 14, the openings 15, 16, through which the nozzle ring 25 extends, so that a free rotation is possible.

Another advantage of the invention in turbofan engines 10 is that interactions between core flow 17 and secondary flow 18 are effectively reduced by the rotation of the invention. An improved performance and low noise emission is the result.

2 shows a churn 20 in a jet engine 19 having a core stream 17. The engine 19 has a single chevron rotating nozzle 20.

FIG. 3 shows that the chevrons 26 at the chevron tips 27 and at the chevron recesses 28, ie in each case rounded off or in each has a radius of more than 2 cm, for example 2 cm to 20 cm is present.

Fig. 4 shows that the nozzle ring 25 is provided with a bearing 42 which is attached to an engine part 29, e.g. an engine cowling, an engine casing or a core shell part, is attached.

As further illustrated in FIG. 4, the nozzle ring 25 is connected to an electromotive drive 30, so that the nozzle ring 25 is motor-driven with the drive. In this case, a first drive element 32 can be fixedly connected to a shaft 31 of the drive. This element 32 drives a second drive element 33, which is fixedly connected to the nozzle ring 25. Both elements 32, 33 may be gears and form a transmission. The wheel 33 is located on the outside of the ring 25 and has approximately the same diameter as the ring 25th

Alternatively, the nozzle ring may have a free run so be executed without a drive motor. The rotation of the ring 25 is effected by a non-motor drive element, for example by inclined slats 34. The slats 34 can act like propellers and are aerodynamically driven by the engine jet. In free mode, the rotation of the nozzle in direction 23 (FIG. 3) and / or rotational speed will adapt to flow 24 (FIG. 3). However, the rotation may also be influenced aerodynamically to rotate in a specific direction 23 and / or rate. More controlled rotation (direction 23) can be achieved by the use of motors 30 (Figure 4). Freely rotatable means that the ring 25 can rotate more than 360 degrees. If the ring 25 could rotate only by a limited angle, that would not be a free rotation. Free running means that no electric motor or the like is used to achieve the rotation of the ring 25. The engine (Fig. 4) has an air inlet 35, a so-called fan 36, a compressor 37, a combustion chamber 38, a turbine 39, the exhaust nozzle 40, a shaft 43 and a housing 41 to which the drive 30 can be attached.

FIGS. 3 and 4 thus show that connections 21 and bearing systems 22 can be used in conjunction with the churn 25 or the discharge nozzle 40.

The invention is not limited to these examples, so other engines such as turboprop engines or other turbofan engines can be used. Also, any feature described or shown of an example having a feature shown or described may be combined with another example. Thus, features of the engine of Fig. 1 with features of the engine of Fig. 4 are combined. For example, a drive 30 according to FIG. 4 can be used for both nozzles 13, 14. Also, one nozzle 13 may have a free run and the other nozzle 14 may have a motor drive and vice versa.

Reference number list

10 turbofan engine

11 plane

12 engine suspension

13 core stream chevron rotating nozzle

14 sheath flow chevron rotating nozzle

15 first opening

16 second opening

17 Kemstrom

18 side stream

19 jet engine

20 core electricity

19 engine

21 Chevron rotary nozzle

22 Chevron rotary nozzle

23 connections

24 storage systems

25 direction

26 flow

27 -

28 -

29 -

30 chevron nozzle

31 nozzle ring

32 chevrons

33 chevron tips 34 chevron depressions

35 engine part

36 electric motor drive

37 wave

38 First drive element

39 Second drive element

40 fins

41 air intake

42 fan

43 compressors

44 combustion chamber

45 turbine

46 exhaust nozzle

47 housing

48 bearings

49 wave

Claims

claims

Chevron nozzle (13, 14, 21, 22, 30) for an engine (10, 12) of an aircraft (11) comprising at least one nozzle ring (31) and arranged on the nozzle ring (31) chevrons (32), characterized in that the Nozzle ring (31) is designed together with the chevrons (32) with at least one rotational speed freely rotatable, so that a position of the chevrons (32) is constantly changeable.

Chevron nozzle according to claim 1, characterized in that the nozzle ring (31) is provided with a bearing (48) which is on an engine part 35, in particular an engine cowling, an engine housing (47) and / or a Kernmantelteil attached.

Chevron nozzle according to claim 2, characterized in that the bearing (48) is a sliding bearing, a rolling bearing or a magnetic bearing.

Chevron nozzle according to one of the preceding claims, characterized in that the nozzle ring (31) with a drive (36) is driven by a motor.

Chevron nozzle according to one of claims 1 to 3, characterized in that the nozzle ring (31) has a free run, the rotation by at least one drive element, in particular by lamellae (40), which are aerodynamically driven by an engine jet.

Chevron nozzle according to one of the preceding claims, characterized in that the chevrons (32) on chevron tips (33) and / or on chevron recesses 34, preferably at both locations, have a radius, in particular at least 2 cm.

7. Use of a chevron nozzle according to one of the preceding claims in an engine (10, 19) with an air inlet (41), a fan (42), a compressor (43), a combustion chamber (44), a turbine (45), a Exhaust nozzle (46) and / or a housing (47).

Use of a chevron nozzle according to one of the preceding claims in an engine (10, 19) with an engine mount (12), wherein the engine mount (12) has at least one recess or opening (15, 16) for at least one nozzle ring

(31).

9. Use of a Chevrondüse according to any one of the preceding claims in a turbofan engine (10), wherein the nozzle (30) for a core stream (13) and / or a sheath flow (14) is used.

10. Use of a Chevrondüse according to any one of claims 1 to 8 in a jet engine (19).