DE102008027275A1 - Air-breathing nacelle for aircraft engine, has circular front contour and sucking unit that is provided for sucking air into nacelle, where sucking unit comprises turbocharger with fan and turbine - Google Patents

Abstract

The present invention relates to aircraft engines and more particularly relates to an air-breathing gondola with integrated turbocharger and / or core engine. It relates in particular to a nacelle for an aircraft engine with a substantially annular front contour, wherein at least one opening is provided as an inlet in the front contour, characterized in that means are provided in the nacelle for sucking the air into the nacelle. According to a preferred embodiment, the nacelle according to the invention comprises at least one gas generator.

Description

The The present invention relates to aircraft engines and relates in particular an air-breathing gondola with integrated turbocharger and / or core engine

A Aeroengine nacelle or fairing is common a circumferentially extending housing, the one centered circular air inlet and outlet Has. In an engine with fan device comprises this gondola the fan device. Here is the outer one Diameter of the nacelle up to 25% larger than the diameter the actual fan device. This enlargement has its origin in the outer contour of the Gondola. This contour strongly influences aerodynamic drag and the airflow characteristics. It comes first of all then to bear, if large bypass conditions from Z. B. 10: 1 and greater should be achieved. In which the propulsion efficiency common in the art flows only the air velocity at the air inlet and outlet a, which is accompanied by a larger gondola Increase in aerodynamic drag, however, takes place no consideration. In contrast, it affects this increase significantly on fuel consumption, so for a bypass ratio that over 10: 1, no improvement despite improved propulsion efficiency fuel consumption, sometimes even deterioration. For the sake of the required reduction of noise emission But high bypass conditions are necessary.

Especially during high speed or cruise operation The aircraft is therefore a nacelle with lower aerodynamic Resistance desirable to the higher propulsion efficiency for a reduction in fuel consumption can. Apart from the accumulating on the contour of the gondola Resistance are the gondola losses directly proportional to the grinding Outer surface. To reduce the resistance the rubbing surface of the gondola be scaled down, what's most effective with a smaller outside diameter the gondola can be realized. An air inlet into the gondola interior, the a part of the throughput of the engine sucks, allows a reduced diameter to the aerodynamic drag to reduce. In the context of this description is called Gondelinneres the part designated by the profile of the contour is. In contrast, the area which encloses the nacelle rotationally symmetric, referred to as the engine interior.

At the Start, in which a pitch of up to 25 ° certainly occurs or when landing and operating at low speed The aircraft is a gondola with a thick, blunt contour the leading edge necessary to a separation of the flow to avoid oblique flow, resulting in a larger nacelle diameter leads. at a gondola with air intake at the front edge, can be on the thick, blunt contour at the front edge are dispensed with, because the incoming air entering the gondola and not to a large elevation the flow rate with subsequent strong delay is forced.

One known way of choosing the nacelle inlet contour is to provide means for changing or adjusting the configuration of the inlet. For example, variable closable inlets can be provided in the contour itself. This is for example in US 3222863 revealed and in DE 4104201 A1 further developed. The resulting versatility and flexibility, however, leads to more complexity. Although this significantly reduces the aerodynamic drag of the nacelle, these measures do not allow the use of a fan or gondola of smaller diameter.

One another problem of the aircraft engines known from the prior art, lies in the incompatibility of thick low pressure wave and small volume flow of the core engine for its aerodynamic and constructive design. Usually you have to a very high hub ratio, making it difficult to split in the compressor and accept unnecessarily heavy weight to to get to the desired bypass ratio.

One Another problem of known from the prior art aircraft engines lies in the fact that with increasing technical load the compressor blades more and more often so-called blisks be used. Blisks are blades that hold the blades fixed with a rotating disc (disk) are connected. Run all Waves of the engine into each other, so does a damage the blisk requires a complete disassembly of the engine.

Of the The present invention is therefore based on the object, an aircraft engine indicate that the above-mentioned problems of the prior art at least partially overcomes.

Especially The present invention therefore has the object, a Specify nacelle, which, with a given by-pass ratio one significantly reduced compared to gondolas of the prior art Diameter has.

In addition, according to a preferred variant of the present invention, the problem of the high hub ratio, the gap attitude in Overcome compressor and excessive weight.

Furthermore should, according to a particularly preferred variant the present invention, a simple replacement of Blisks be possible without having to disassemble the whole engine.

According to the invention this task by an engine with a nacelle of the genus according to the preamble of claim 1, characterized in that in the nacelle at least a turbocharger is integrated.

Further Preferred aspects of the present invention are defined by the subclaims described.

When Gondola is in the context of the present invention, the housing an engine, which at least one fan and whose turbine encloses. A gondola according to the invention is referred to in this description as a breathing gondola. Gondolas, which at the front contour an inlet for air are known from the prior art as described above. An inventive breathing gondola has a such enema on the front contour, wherein in addition, integrated in the housing, at least one turbocharger provided is. With the help of this turbocharger, air becomes active in the housing pulled in and compressed so that this air, downstream, after the turbocharger can be admixed with the secondary flow and after the fan. According to the invention, at least 10%, but preferably 20% or more, of the air flow rate through the gondola accomplished. The turbocharger can, for example by means of powered by the working gas, as a subset of the central arranged low-pressure turbine is tapped, which the fan drives.

It should be noted that the above-mentioned US Patent US 3222863 no breathing nacelle in the sense of the present invention is because the throughput sucked through the nacelle before the fan rotor is supplied to the engine flow to the engine. The US 3222863 Rather discloses a gondola with variable inlet, which can adapt to the airspeed.

Also in the above-mentioned German Offenlegungsschrift DE 4104201 A1 There is no breathing nacelle for the purposes of the present invention. Since there is no loader in the nacelle, any given throughput passing through the nacelle will not significantly add to the thrust. Due to the flow caused in the nacelle, frictional losses are more likely. In contrast, turbocharger in the nacelle is advantageous according to the invention, which build up a compressor pressure ratio comparable to that of the fan apparatus, that is, for example, between 1.3: 1 and 1.5: 1. For this purpose, not much throughput and residual pressure ratio for the drive of the supercharger turbine is needed, so it can be tapped relatively far back in the power turbine of the main engine and directed by the sidestream out to the nacelle. A bleed at the outlet of the power turbine is not sufficient in contrast, because there the pressure is too low.

A additional possibility is in the breathing gondola a core engine with at least one low-pressure compressor, a high pressure compressor, a fuel cell, a high pressure turbine and at least provide a low-pressure turbine. The resulting Air flows can then be diverted so that driven the turbine of the centrally located fan becomes. In this way, on the one hand, the one with one another Axis-related problems avoided. Because the axes are not anymore On the other hand, the replacement is damaged Blisks greatly simplified.

at This gondola integrated gas generator becomes a pressure ratio from 40: 1-50: 1 needed, which is only in two stages or more can be represented - so a low pressure system (ND system) and a high-pressure system (HD system) is required. In the ND system, a pressure ratio of about 8: 1-9: 1 build up and in the HD system a pressure ratio of 6: 1, but because of the higher inlet temperature about the same turbine power needed.

It should be reiterated at this point that the breathing gondola necessary condition for the use of one in the Gondola integrated gas generator is. The inventive breathing gondola can also be used in a normal engine with centrally located around the low pressure shaft core engine (gas generator) Find application.

The Invention will now be described by way of example with reference to FIGS various embodiments described in detail.

1 shows an aircraft engine according to the prior art

2 shows a TS diagram for a closed ideal Joule process as well as an open real gas turbine process

3 shows an aircraft engine with a breathing nacelle according to a first embodiment of the present invention.

4 shows roughly schematically a detail of 3

5 shows the front view of an aircraft engine according to the invention breathing gondola

6 shows the TS diagram of an engine according to an embodiment of the present invention

7 shows a gas generator with its circumferentially arranged in the nacelle components for an engine with gondola according to the invention in one embodiment and the flow directions.

8th schematically shows gas flow connections between a fan motor and a breathing nacelle according to the invention according to an embodiment according to 7

9 shows a gas generator with its circumferentially arranged in the nacelle components for an engine with gondola according to the invention in one embodiment and the flow directions and the required in the main engine second combustion chamber.

10 schematically shows gas flow connections between a blower unit and a breathing nacelle according to the invention according to an embodiment 9

In order to be able to explain the invention in an illustrative manner, it is advantageous first of all to roughly describe the structure of an engine according to the prior art 1 to explain.

1 shows an aircraft engine 1 in cross-section with gondola 3 , fixed parts 5 and rotor parts 7 , The rotor parts 7 include a low pressure system with input hub 9 the blower device 11 , Low-pressure compressor 13 . 13 ' , Low pressure turbine 15 . 15 ' , and output hub 17 all through a brass axis 19 are connected. The low pressure turbine 15 . 15 ' drives the fan and the low-pressure compressor. The rotor parts 5 Also includes a high pressure multi-stage high pressure compressor system 21 . 21 ' . 21 '' and high-pressure turbines 23 . 23 ' all through a high pressure shaft 25 are connected. The high pressure system is between the low pressure compressors 13 . 13 ' and the low-pressure turbine 15 arranged. The high pressure shaft 25 encases the brass axis 19 ,

The fixed parts 5 include flow elements 31 . 31 ' and striving 29 . 29 ' , The flow elements 31 . 31 ' ensure that the cross-section of the air duct passing through the center decreases from compressor stage to compressor stage and increases again downstream at the turbines. In addition, the fixed parts include 5 a burner device which, seen downstream, is arranged after the last high-pressure compressor and before the first high-pressure turbine. Not shown in the drawing are stator blades in the bypass, which belong to the fan and remove the swirl generated by the fan blades again, whereby the pressure increases. Also not shown are the pillars that hold the core engine centered in the nacelle and initiate the thrust forces directly over the pylon in the wing.

The cross section of the gondola 3 is streamlined and chosen so that the air that flows around the engine doing this as possible without detachment - especially in Fehlanströmung, as occurs in hired aircraft and in cross-flow by wind at takeoff and landing.

During operation of the engine, the fan device rotates 11 and sucks air into the engine. Part of the air enters the area of the compressors and is now exposed to different pressures and temperatures, which can be described thermodynamically approximated by means of the Joule process, consisting of two isentropes and two isobars:
From the compressors, the air is first compressed at substantially constant entropy. This increases the temperature or the enthalpy. In the TS diagram of the 2 this is the transition from A to B. The air thus compressed comes into the area of the burner and is burnt together with injected fuel under almost constant pressure (B to C). Combustion produces temperatures of up to 1700 ° C. The hot combustion gases flow through the system of high-pressure and low-pressure turbines, with the turbine stator of each turbine stage generating a high-speed spin which is taken out of the rotor by the transition from the stationary to the rotating system and then back into the stationary system, releasing mechanical work. The fluid is expanded and the enthalpy contained in the fluid is converted into mechanical energy, ie drives the turbines. As a result, the temperature drops at a substantially constant entropy (C to D). The processes in the gas turbine are best described by an open process, since no cooling of the fluid takes place after the turbine, but only new air is sucked. In the 2 Additionally shown with a dashed line is the ideal, closed Joule process.

The through the low pressure turbine 15 rotated blaster device 11 ensures that air is drawn into the engine and mainly into the outer areas of the interior of the gondola and flows as a side stream through the engine and for the actual drive that provides thrust. With a high bypass ratio, thrust of size x is generated at high throughput but relatively small exit velocity, resulting in high propulsion efficiency and thus lower fuel consumption and low noise, but can not be integrated into the aircraft because of its size and creates additional drag.

In contrast, shows 3 a first embodiment of an inventive breathing gondola. The lower part of the nacelle and the rotor system are the same as those in 1 shown engine. For clarity, the corresponding reference numerals have been omitted. However, the front contour of the upper part of the nacelle includes an enema 303 , In addition, the upper part of the nacelle comprises an integrated turbocharger 305 , Such a turbocharger is in 4 only roughly schematic with fan 307 and turbine 309 shown. For reasons of clarity, the illustration of various elements which are directly known to the person skilled in the art, such as, for example, the stator, has been dispensed with.

The turbine of the turbocharger 309 Of course, it has to be designed in such a way that it redirects and can work with it. The turbine is in communication with a channel 313 , Through this channel, a part of the working gas is passed from the engine. This gas acts on the turbine 309 and drives them. The pressurized gas is directed by the turbocharger towards the end of the upper nacelle. The turbocharger thus sucks in air, which flows downstream toward the end of the nacelle and can be efficiently fed into the sidestream. The 3 Here, it becomes immediately clear that the task of the fan device is partly taken over by the air flowing through the nacelle and the turbocharger, and this air also contributes to the thrust of the engine. This can be 10 to 20% of the total engine throughput. But this can be chosen to be much smaller diameter of the fan device.

5 shows the front view of an inventive engine 501 according to the first embodiment. Clearly visible is the centrally located fan apparatus 503 as well as nine in the upper half of the gondola 505 semicircular turbocharger 507 . 509 . 511 . 513 . 515 . 517 ,

8th In contrast, shows a second embodiment of the present invention. Here, not only a turbocharger is integrated into the upper part of the nacelle, but also the core engine (gas generator) with a combustion chamber. Thus, the shaft of the fan device is separated from the shaft of the gas generator.

Of particular interest here is that in addition in the nacelle, the waves of the low pressure system and the high pressure system can be separated with the fuel cell and laid parallel. The low-pressure system can consist of several parallel turbochargers. 7 schematically illustrates how such a system could be interconnected with respect to gas flows:
Air is sucked through the gondola inlet, which then enters the five low-pressure compressors shown in the diagram 701 arrives. Compressed air then becomes the high pressure system 705 directed. The high pressure system 705 includes a high pressure compressor 707 , a fuel cell 709 and a high-pressure turbine 711 , From the high-pressure turbine, the working gas is routed to the lukewarm turbines of the low-pressure system where they drive the sluice compressors. After the low-pressure turbine, the gas is still hot enough and still has enough pressure to drive the power turbine. It should be noted that 7 only a schematic representation of the conditions. For example, unlike the illustrated, the drive shaft between the turbine and compressor must be centrally located. Likewise, the gas flow at the compressor outlet must cover the entire circumference. 6 shows the TS diagram of a corresponding thermodynamic process. This corresponds to the 2 However, at point a, the temperature and entropy of the gas between low pressure compressor and high pressure compressor is given at point c, the temperature and entropy of the gas before the low pressure turbine is given and at point d, the temperature of the gas to the low pressure turbine of the gas generator, or before the power turbine is given.

8th shows a possible cross section of an engine 801 according to this embodiment. The engine 801 includes a gondola 803 and a fan device 805 passing through the brass axis 807 with a useful turbine driving them 809 connected is. The gondola 803 includes at the front of the contour an enema 810 in the form of an opening, through the air in the nacelle 803 is sucked. Provided in the nacelle is the above-described system of low pressure compressors / turbines and a high pressure compressor / turbine with burner. The engine 801 also includes a system of gas guides 813 , the hot gas flowing from the low pressure turbines of the gas generator to the power turbine 809 directs and drives them.

According to the scheme of 9 shown possibility to connect a system gas flow technology is at a number of parts of the low-pressure compressor 901 a portion of the gas branched off directly for the power turbine. But between these low-pressure compressors and the power turbine then still has a fuel cell - indicated in the diagram with a star - be interposed. The restli The gas of the low-pressure compressor enters the high-pressure system 905 and then into the low-pressure turbines 903 guided and drives these. After the low-pressure turbines, the gas is then passed directly into the side stream of the engine.

The Invention has been exemplified by some embodiments and the accompanying pictures explained. These However, examples are not meant to be limiting. Of the The person skilled in the art will become immediately different from the present description However, embodiments can realize that also fall within the scope of the present invention.

Disclosed became an air-breathing gondola, d. H. an engine case with inlet and integrated turbocharger and outlet, which in the Side flow of the engine promotes. The outer diameter the air-breathing gondola according to the invention can in the same Ratio smaller than the outside diameter the fan rotor, which then only 80-90% of the throughput must be able to swallow. About that In addition, the contraction of the nacelle in the rear part is smaller and hence the delay, which reduces the losses.

Around a high percentage of the total engine throughput through the Gondola reach, it may be advantageous to the arrangement of Turbochargers over the full gondola circumference provide because because the relatively small diameter of the loader many parallel units must be accommodated. On the other hand, the offers Limitation of the inlet opening to the upper one 2/3 or the top half benefits.

About that In addition, a nacelle according to the invention has been disclosed with integrated core engine or gas generator. This will do that Problem of incompatibility of thick low pressure wave and small volume flow of the core engine for its aerodynamic and constructive design (very high hub ratio, unfavorable gap position in the compressor and unnecessary high weight) avoided. Besides, you can now Blisks are used without causing blade damage in the core engine a complete engine decomposition would be required.

The Gondelintegrierte core engine can only be used in conjunction with the air-breathing Gondola be realized. About reducing the outer surface of the Gondola beyond the outer radius, comes at gondelin integrated core engine still the area reduction over add the shortened engine length if that Core engine is taken out of the main engine.

905

High pressure system

903

Low-pressure turbines

901

Low-pressure compressor

811

enema

809

power turbine

807

blower axis

805

Blaster device

803

gondola

801

engine

711

High-pressure turbine

709

fireplace insert

707

High-pressure compressors

705

High pressure system

703

Low-pressure turbines

701

Low-pressure compressor

309

turbine

307

fan

305

turbocharger

303

enema

31 31 '

flow elements

29 29 '

pursuit

27

front contour

25

High pressure shaft

23 23 '

High pressure turbine

21 21 ', 21' '

High-pressure compressors

19

blower axis

17

output hub

16

blower turbine

15

Low-pressure turbines

13 13 '

Low-pressure compressor

11

blower device

9

input hub

7

rotor parts

5

fixed parts

3

gondola

1

Jet Engine

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - US 3222863 [0005, 0015, 0015]
• - DE 4104201 A1 [0005, 0016]

Claims (7)

Gondola for aircraft engine with a substantially annular front contour, wherein in the front contour at least one opening is provided as an inlet, characterized in that means are provided for sucking the air into the nacelle in the nacelle Gondola according to claim 1, characterized characterized in that said means for sucking the air at least include a turbocharger with compressor and turbine. Gondola according to one of the claims 1 or 2, characterized in that the opening over the upper third, preferably at least over the upper half the annular front contour and more preferably about the upper 2/3 of the annular front contour extends. Gondola according to one of the preceding Claims, characterized in that opening and means for drawing the air into the nacelle in such a way are that at least 10% preferably 15%, more preferably 20% the entire air intake of the engine through the opening can be accomplished. Gondola according to one of the preceding Claims, characterized in that means provided are those that allow the air sucked into the nacelle and / or their reaction products, the flow, in the area, The gondola surrounds, to mix. Gondola according to one of the preceding Claims, characterized in that the gondola at least includes a gas generator. Gondola according to claim 6, characterized characterized in that the gas generator several in parallel in the nacelle arranged low pressure systems and at least one high pressure system includes.