LEADING-EDGE DEVICE FOR AN AIRCRAFT

Abstract

A leading-edge device for an aircraft, the device comprising a flow body having a front skin, a back skin, a spar and an air inlet. The front skin is curved around a spanwise axis to form a bottom section and a top section.

A leading edge of the flow body is arranged between the bottom section and the top section. The spar extends from the bottom section to the top section. The front skin, the back skin and the spar enclose at least one air chamber that is in fluid communication with the air inlet. An outlet portion is arranged at least directly adjacent to the bottom section of the front skin. The outlet portion comprises a plurality of air outlets for letting air from the at least one air chamber exhaust through the air outlets.

Claims

1. A leading-edge device for an aircraft, comprising a flow body having a front skin, a back skin, a spar and an air inlet, wherein the front skin is curved around a spanwise axis to form a bottom section and a top section, wherein a leading edge of the flow body is arranged between the bottom section and the top section, wherein the spar extends from the bottom section to the top section, wherein the front skin, the back skin and the spar enclose at least one air chamber that is in fluid communication with the air inlet, wherein an outlet portion is arranged at least directly adjacent to the bottom section of the front skin, and wherein the outlet portion comprises a plurality of air outlets for letting air from the at least one air chamber exhaust through the air outlets.

2. The leading-edge device according to claim 1, wherein the air outlets extend through the front skin in the bottom section.

3. The leading-edge device according to claim 1, wherein the air outlets extend through a lower flange of the spar.

4. The leading-edge device according to claim 1, wherein the air outlets are formed as dimples in a bottom section of the back skin.

5. The leading-edge device according to claim 1, wherein the spar comprises a lower flange attached to the bottom section of the front skin, wherein the back skin is attached to the lower flange, such that the back skin and the bottom section enclose the lower flange, wherein the lower flange comprises a plurality of slots extending underneath the back skin as the air outlets.

6. The leading-edge device according to claim 1, wherein the back skin is attached to the spar, wherein a lower end edge of the back skin and the spar enclose a gap, wherein the back skin comprises a plurality of dimples in fluid communication with the air inlet, wherein the dimples have lower openings that face into the gap and act as the air outlets.

7. The leading-edge device according to claim 6, wherein the dimples extend between the back skin and a part of the spar and comprise upper openings facing into the at least one air chamber.

8. The leading-edge device according to claim 1, further comprising a girder attached to the spar and the back skin, wherein the girder comprises an upper edge in a distance to the front skin and a lower edge adjacent to the bottom section of the front skin, and wherein the girder comprises a plurality of slots extending between the upper edge and the lower edge, such that lower ends of the slots adjacent the bottom section form the air outlets.

9. The leading-edge device according to claim 8, wherein flow directions of the lower ends are arranged transverse to the girder.

10. The leading-edge device according to claim 1, wherein the air outlets are configured to form an exhaust flow that is attached to and runs along the front skin in the bottom section.

11. A wing for an aircraft, having a fixed leading edge and a leading-edge device according to claim 1, wherein the leading-edge device is movable between a retracted position directly forward of the fixed leading edge and at least one extended position at a further distance to the fixed leading edge.

12. The wing of claim 11, wherein the air outlets are configured to exhaust the air in a region in front of a lowermost part of the fixed leading edge in the retracted position the leading-edge device.

13. The wing of claim 11, wherein the air outlets are arranged in front of the fixed leading edge.

14. An aircraft having at least one wing of claim 11, wherein the air inlet is in fluid communication with a source of heated air.

15. The aircraft of claim 14, further comprising at least one turbofan engine having at least one bleed air port, wherein the air inlet is in fluid communication with the at least one bleed air port, such that bleed air delivered by the at least one turbofan engine is the source of heated air.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Other characteristics, advantages and potential applications of the present invention result from the following description of the exemplary embodiments illustrated in the figures. In this respect, all described and/or graphically illustrated characteristics also form the object of the invention individually and in arbitrary combination regardless of their composition in the individual claims or their references to other claims. Furthermore, identical or similar objects are identified by the same reference symbols in the figures.

[0028] FIGS. 1 and 2 show a first exemplary embodiment of a leading-edge device with outlets extending through the bottom section of the front skin in two different viewing directions.

[0029] FIGS. 3 and 4 show a second exemplary embodiment of a leading-edge device with dimples in the back skin in two different viewing directions.

[0030] FIGS. 5 and 6 show a third exemplary embodiment of a leading-edge device with slots in a flange of the spar in two different viewing directions.

[0031] FIG. 7 shows a schematic view of the air flow in the third exemplary embodiment.

[0032] FIG. 8 shows a fourth exemplary embodiment of a leading-edge device with a dimple in the back skin.

[0033] FIG. 9 shows a fifth exemplary embodiment of a leading-edge device with dimples in a girder and a back skin.

[0034] FIG. 10 shows a sixth exemplary embodiment of a leading-edge device with a slot in a girder.

[0035] FIG. 11 shows an aircraft having at least one leading-edge device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] FIG. 1 shows a leading-edge device 2 for an aircraft in a first exemplary embodiment. The device 2 comprises a flow body 4 having a front skin 6, a back skin 8, a spar 10 and an air inlet 12. The front skin 6 is curved around a spanwise axis 14 to form a bottom section 16 and a top section 18. A leading edge 20 is arranged between the bottom section 16 and the top section 18 and extends in a spanwise direction. The spar 10 extends between the bottom section 16 and the top section 18 and is connected to the front skin 6 in both sections 16 and 18. By arranging the spar 10 in this manner, a first air chamber 22 is created between the spar 10 and the front skin 6, which first air chamber 22 is located in front of the spar 10, i.e., adjacent the leading edge 20.

[0037] The spar 10 comprises an upper flange 24, which is arranged to be parallel to the top section 18 of the front skin 6. Behind the upper flange 24, the back skin 8 is coupled with the front skin 6. Opposite to the upper flange 24, a lower flange 34 of the spar 10 is provided, which is coupled with the bottom section of the front skin 6. Hence, the spar 10 is arranged to extend between the bottom section 16 and the top section 18. The back skin 8, in turn, is arranged at a side of the spar 10 that is opposite the leading edge 20. It may comprise a bottom flange 26, which is also coupled with the bottom section 16 of the front skin 6. The back skin 8 is also curved around the spanwise axis 14 or an axis parallel thereto and encloses a second air chamber 28 with the front skin 6 and the spar 10.

[0038] In this exemplary embodiment, the air inlet 12 is a part of a tubular member 30, through which air can flow into the first air chamber 22. By using air that has an elevated temperature, the first air chamber 22, and thus a respective part of the front skin 6, is heated up and ice accumulations on the front skin 6 around the leading edge 20 can be prevented or removed. By providing a fluid communication between the first air chamber 22 and the second air chamber 28, air is forced to flows into the second air chamber 28 to also heat up a rear part of the flow body 4. From there, the air is allowed to exit the flow body 4. For this, several air outlets 32 are provided that extend through the spar 10 and the bottom section 16 of the front skin 6. The resulting air flows are substantially perpendicular to the front skin 6 in this region.

[0039] The spar 10 comprises a lower flange 34 that is arranged at an angle to a main part 36 of the spar 10 and rests flushly on the front skin 6 in the bottom section 16. Hence, the air outlets 32 extend through two material layers. While the air outlets 32 are provided in the form of slots in the lower flange 34, they may comprise a different shape in the front skin 6. In the following, the region or portion of the flow body 4 where the air exits the flow body 4 is referred to as outlet portion 38. By placing the outlet portion 38 in the bottom section 16 of the front skin 6, air exits the flow body 4 in a manner that prevents hot air to impinge a fixed leading edge of the wing (not shown), to which the leading-edge device 2 is attached.

[0040] In FIG. 2 another viewing direction is chosen and lower ends 40 of the air outlets 32 are shown. The lower ends 40 may comprise a circular shape. It is clearly apparent that an airflow 42 is routed from the second air chamber 28 through the air outlets 32 in a direction perpendicular to the bottom section 16 at the outlet portion 38.

[0041] As described further above, the lower flange 34 may also face in a forward direction, such that the air outlets 32 only extend through the front skin 6 in the bottom section 16.

[0042] In FIGS. 3 and 4, another exemplary embodiment in the form of a leading-edge device 43 is shown. While the basic arrangement is similar to the leading-edge device 2 of FIGS. 1 and 2, a different outlet portion 44 is created. Here, the back skin 8 comprises a lower flange 46, which comprises several dimples 48 that bulge away from the front skin 6 in the bottom section 16. Each dimple creates a flow channel between the front skin 6 and the back skin 8 in fluid communication with the second air chamber 28. The outer ends of the flow channels opposite to the second air chamber 28 thus create air outlets 50. Due to the given shape an orientation of the dimples, air that exits the second chamber 28 leaves the leading-edge device 43 in a direction parallel to the bottom section 16 of the front skin 6.

[0043] This is further shown in FIG. 4 from another viewing direction. Here, the dimples 48 are offset to the lower flange 34 of the spar 10 and allow an airflow 42 to change its direction to flow along the bottom section 16 towards the air outlets 50.

[0044] Instead of dimples, also simple holes 49 (shown in dashed lines) may be arranged in the back skin 8 and act as air outlets. It is reasonable to place these holes 49 as close to the lower flange 46 or the lower end of the back skin 8 as possible. When using the holes 49 as shown, at least the lower flange 46 may be designed more simply.

[0045] FIGS. 5 and 6 show another exemplary embodiment in form of a leading-edge device 55. Here, the spar 10 comprises a lower flange 51, which is attached to the bottom section 16 of the front skin 6. The bottom flange 26 of the back skin 8 is attached to a top side of the lower flange 51. The lower flange 51 comprises a plurality of slots 52 that extend from the second air chamber 28 underneath a chordwise extension of the bottom flange 26 of the back skin 8 and thus provide flow channels both in fluid communication with the second air chamber 28 and the environment. Hence, an outlet portion 54 is created, through which air leaves the second air chamber 28. The air flows through the slots 52, wherein distal ends 53 of the slots 52 opposite the spar 10 act as air outlets leading the air into the environment.

[0046] In FIG. 7, a resulting air flow in the device 55 according to FIGS. 5 and 6 is schematically shown. Here, air enters the tubular member 30 through the air inlet 12 and afterwards exits the tubular member 30 through a plurality of openings (not shown) to impinge onto an inner side of the front skin 6. The air flows through a passage 57 into the second chamber 28 and is thus directed to the outlet portion 54. From there, it exits the leading-edge device 55 and flows into the environment away from a fixed leading edge 56. The air flow 42 hardly touches the fixed leading edge 56.

[0047] FIG. 8 shows a further exemplary embodiment in the form of a leading-edge device 58 with a spar 60 that comprises a kink 62, which substantially extends in a spanwise direction. The back skin 8 is attached to the spar 60 and comprises several dimples 64 that form individual flow channels 66, which are in fluid communication with both the second air chamber 28 and the environment. The flow channels 66 extend along the spar 60 towards the bottom section 16 of the front skin 6.

[0048] The back skin 8 and, consequently, the flow channels 66 end at a slight distance from the bottom section 16 of the front skin 6. This allows air to exit from the flow channels 66 in a direction perpendicular to the bottom section 16 through air outlets 68 in the form of open ends of the flow channels 66. By impinging the bottom section 16, the air flow is bent to flow along the bottom section 16 in a backwards direction substantially chordwise. A detail in FIG. 8 shows a section A-A through the spar 60 and a dimple 64. As an example, the dimple 64 creates a flow channel 66 with a trapezoidal cross-section.

[0049] A longitudinal seal 65 is arranged between the flow body 4 and the fixed leading edge 56. The seal 65 is arranged directly above the dimples 64.

[0050] FIG. 9 shows a leading-edge device 70, which has some similarities with the device 58 of FIG. 8. Here, a lower girder 72 is provided, to which the spar 60 is attached. The spar 60 has several dimples 74 in a section between the kink 62 and the girder 72, wherein the dimples 74 bulge into the direction of the leading edge 20. In a region behind the girder 72, the back skin 8 has associated dimples 76, which face away from the leading edge 20 and are arranged behind the girder 72. Similar to FIG. 8, the back skin 8 ends at a distance from the bottom section 16 of the front skin 6 to form an air outlet 78. The longitudinal seal 65 can be arranged above the dimples 76, which is below the position possible in the exemplary embodiment of FIG. 9.

[0051] FIG. 10 shows a further leading-edge device 79 having a lower girder 80, which comprises an internal air channel 82, which is open at a side facing away from the leading edge 20 form an air outlet 84. Here, the longitudinal seal 65 is arranged approximately in a position comparable to the position in FIG. 9.

[0052] Finally, FIG. 11 shows aircraft 86 having wings 88, which exemplarily comprise at least one leading-edge device 2. However, the other leading-edge devices 43, 58 or 70 may also be arranged on the wings 88 as an alternative or as an addition. The aircraft 86 further comprises engines 90, which are exemplarily realized as turbofan engines. They comprise bleed air ports (not shown), which may deliver air at an elevated temperature to the leading-edge device 2.

[0053] In addition, it should be pointed out that characteristics or steps which have been described with reference to one of the above exemplary embodiments may also be used in combination with other characteristics or steps of other exemplary embodiments described above.

[0054] 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.

REFERENCE NUMERALS

[0055] 2 leading-edge device [0056] 4 flow body [0057] 6 front skin [0058] 8 back skin [0059] 10 spar [0060] 12 air inlet [0061] 14 spanwise axis [0062] 16 bottom section [0063] 18 top section [0064] 20 leading edge [0065] 22 first air chamber [0066] 24 upper flange of spar [0067] 26 bottom flange of back skin [0068] 28 second air chamber [0069] 30 tubular member [0070] 32 air outlet [0071] 34 lower flange of spar [0072] 36 main part of spar [0073] 38 outlet portion [0074] 40 lower end of air outlet 32 [0075] 42 airflow [0076] 43 leading-edge device [0077] 44 outlet portion [0078] 46 lower flange of back skin [0079] 48 dimple [0080] 49 hole/air outlet [0081] 50 air outlet [0082] 51 lower flange of spar [0083] 52 slot [0084] 53 air outlet/distal end [0085] 54 outlet portion [0086] 55 leading-edge device [0087] 56 fixed leading edge [0088] 57 passage [0089] 58 leading-edge device [0090] 60 spar [0091] 62 kink [0092] 64 dimple [0093] 65 seal [0094] 66 flow channel [0095] 68 air outlet [0096] 70 leading-edge device [0097] 72 lower girder [0098] 74 dimple [0099] 76 dimple [0100] 78 air outlet [0101] 79 leading-edge device [0102] 80 girder [0103] 82 air channel [0104] 84 air outlet [0105] 86 aircraft [0106] 88 wing [0107] 90 engine