Aircraft flap

Abstract

An aircraft flap comprises an upper wing surface and a lower wing surface which are opposite to each other, and a cavity is defined by the upper wing surface and the lower wing surface; the noise reduction device is arranged in the cavity and comprises a first noise reduction structure, the first noise reduction structure comprises a perforated plate and an upper part and a lower part, the upper part is embedded in the upper wing surface, and the lower part is embedded in the lower wing surface; a second noise reduction structure including foam metal, disposed between the upper portion and the lower portion of the first noise reduction structure, and attached to the first noise reduction structure; and the third noise reduction structure comprises a super-structure partition plate and is embedded into the second noise reduction structure. According to the composite superstructure design integrating the three noise reduction structures together, the structural stability of the noise reduction device can be guaranteed, and meanwhile, the jet flow installation noise of the aircraft engine can be effectively reduced.

Description

Technical Field

[0001] The present invention relates to the field of noise control. Specifically, the present invention relates to an aircraft flap having a noise reduction device. Background Art

[0002] Engine noise is the main external noise source during the takeoff and landing phases of an aircraft. Reducing engine noise can improve the airworthiness passability and market competitiveness of the aircraft. Increasing the engine bypass ratio is one of the most effective means. However, increasing the engine bypass ratio causes the engine installation position to be closer and closer to the wing, resulting in interference between the engine jet and the wing / flap, and also increasing the reflection of the jet noise by the wing / flap. The wing / flap interference causes an increase in the low-frequency noise level of the jet noise, while the wing / flap reflection causes an increase in the high-frequency band of the jet noise. Among them, the increase amplitude in the low-frequency band is higher than that in the high-frequency band. To reduce noise, especially to reduce the increased low-frequency noise caused by wing / flap interference, the interference between the jet and the flap can be weakened by modifying the trailing edge of the flap, and a certain sound-absorbing structure can be designed for sound absorption to reduce the low-frequency noise.

[0003] However, the commonly used noise reduction materials and / or structures in the prior art have problems such as good noise reduction effect but poor structural strength, or good structural stability but poor noise reduction effect.

[0004] Therefore, it is necessary to propose an improved aircraft flap that can solve the problems and defects existing in the above prior art. Summary of the Invention

[0005] The object of the present invention is to provide an aircraft flap provided with a noise reduction device, the noise reduction device having a stable structure and being capable of effectively reducing the engine jet installation noise.

[0006] According to the present disclosure, an aircraft flap is proposed, which includes: an upper wing surface and a lower wing surface opposite to each other, the upper wing surface and the lower wing surface surrounding to form a cavity; and a noise reduction device disposed in the cavity, including: a first noise reduction structure including an upper part and a lower part, wherein the upper part is embedded in the upper wing surface and the lower part is embedded in the lower wing surface; a second noise reduction structure disposed between the upper part and the lower part of the first noise reduction structure and attached to the first noise reduction structure; and a third noise reduction structure embedded in the second noise reduction structure. Among them, the first noise reduction structure embedded in the upper wing surface and the lower wing surface can ensure the stability of the frame structure of the noise reduction device, and the second noise reduction structure and the third noise reduction structure arranged together enable effective noise reduction. This composite structure in which the three noise reduction structures are integrated enables effective reduction of the engine jet installation noise while ensuring the stability of the structure of the noise reduction device.

[0007] According to another aspect of the present disclosure, the noise reduction device is arranged in a region where the engine jet interference of the aircraft flap is strong. Arranging in a region with strong engine jet interference can effectively achieve the purpose of reducing noise. If the arrangement range is too large, since the structure and material of the noise reduction device are significantly different from those of the aircraft flap, the presence of the noise reduction device may affect the structural strength and aerodynamic performance of the aircraft flap itself.

[0008] According to another aspect of the present disclosure, the upper part of the first noise reduction structure is shaped to be flush with the outer surface of the upper wing surface, while the lower part of the first noise reduction structure is shaped to be flush with the outer surface of the lower wing surface. This arrangement can keep the airfoil of the aircraft flap consistent with that without installing the noise reduction device, thus avoiding affecting the aerodynamic performance of the aircraft flap.

[0009] According to another aspect of the present disclosure, the second noise reduction structure extends from the upper part of the first noise reduction structure to the lower part of the first noise reduction structure, filling the part between the upper part and the lower part of the first noise reduction structure in the cavity. For better noise reduction effect, the upper part and the lower part of the first noise reduction structure sandwich the second noise reduction structure, thus avoiding the existence of cavities that contribute to sound propagation. Additionally, it also helps to support the upper part and the lower part of the first noise reduction structure. The second noise reduction structure preferably uses metal foam, which is mainly used to reduce high-frequency noise.

[0010] According to another aspect of the present disclosure, the third noise reduction structure includes a plurality of noise reduction members arranged in a staggered manner in the chordwise direction in the second noise reduction structure. Among them, one noise reduction member of the plurality of noise reduction members extends from the upper part or the lower part of the first noise reduction structure towards the lower part or the upper part, while its adjacent another noise reduction member extends in the opposite direction from the lower part or the upper part of the first noise reduction structure towards the upper part or the lower part. This staggered arrangement forms a superstructure. Since the noise reduction members themselves block the sound propagation, the sound waves of the engine jet noise entering the noise reduction device are forced to sequentially pass through the gaps between the plurality of noise reduction members and the upper part or the lower part of the first noise reduction structure, extending the propagation path of the sound waves in the noise reduction device, which is beneficial to further reducing low-frequency noise.

[0011] However, the present invention is not limited thereto. In an alternative embodiment, it is also conceivable that the third noise reduction structure includes a plurality of noise reduction members, where each of the plurality of noise reduction members extends from the upper part of the first noise reduction structure to the lower part of the first noise reduction structure. In this way, a plurality of noise reduction compartments are formed between the first noise reduction structures, and these compartments combined with the second noise reduction structure can also effectively reduce noise.

[0012] According to another aspect of the present disclosure, the first noise reduction structure includes a porous structure, the second noise reduction structure is a high-frequency noise reduction structure, and the third noise reduction structure includes a low-frequency noise reduction structure. Further, the porous structure of the first noise reduction structure includes a perforated plate, the high-frequency noise reduction structure of the second noise reduction structure includes metal foam, and the low-frequency noise reduction structure of the third noise reduction structure includes a plurality of partitions. The perforated plate has a stable structure, which helps to maintain the structural stability of the noise reduction device and does not deform even when subjected to high-speed air flow impact during flight, thus ensuring the noise reduction performance of the entire noise reduction device and avoiding affecting the aerodynamic performance of the aircraft flap where the noise reduction device is installed. Metal foam has excellent high-frequency noise reduction performance, and combined with the plurality of partitions with excellent low-frequency noise reduction performance that make up the superstructure, it can effectively absorb engine jet noise in a relatively wide frequency band.

[0013] According to another aspect of the present disclosure, the aircraft flap includes a leading edge and a trailing edge that are opposite to each other along the chordwise direction. In a preferred embodiment of the present invention, the noise reduction device is arranged closer to the trailing edge. However, the present invention is not limited thereto, and the noise reduction device can be arranged at any position as long as it corresponds to the region where the engine jet interference is strong.

[0014] According to another aspect of the present disclosure, the upper and lower portions of the first noise reduction structure of the noise reduction device are shaped into a rectangle. However, the present invention is not limited thereto, and in alternative embodiments, other suitable shapes such as polygons and ovals can be envisaged as long as they cover the region where the engine jet interference is strong and do not significantly affect the aerodynamic profile of the aircraft flap.

[0015] According to another aspect of the present disclosure, the second noise reduction structure is adhered to the upper and lower portions of the first noise reduction structure. Additionally, the first noise reduction structure is firmly connected to the upper wing surface and the lower wing surface of the aircraft flap by means of connectors such as screws and rivets. In this way, the noise reduction device can be firmly installed on the aircraft flap, and the second noise reduction structure can also be prevented from being accidentally displaced due to being sandwiched between the two portions of the first noise reduction structure.

[0016] The noise reduction device used for the aircraft flap according to the present invention has a composite structure. Specifically, it uses a perforated plate as the first noise reduction structure, which is embedded in the upper and lower wing surfaces of the flap to ensure the stability of the frame structure of the noise reduction device; it uses metal foam as the second noise reduction structure, which is filled between the perforated plates to ensure good high-frequency noise reduction effect; further, a superstructure including a plurality of partitions is inserted into the second noise reduction structure to extend the sound propagation path of the noise in the noise reduction device, thereby further reducing low-frequency noise.

[0017] The present invention content is provided to introduce concepts in a simplified form, and these concepts will be further described in the following detailed implementation manners. The present invention content is neither intended to identify the key features or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter. Through the following detailed description of the embodiments and the drawings, other aspects and advantages of the present invention will become apparent. Brief Description of the Drawings

[0018] To more fully understand the present disclosure, reference may be made to the following description of exemplary embodiments in conjunction with the drawings. The drawings are not intended to limit the present disclosure to the specific embodiments depicted, and are not necessarily to scale. In the drawings:

[0019] Figure 1 is a schematic view of an aircraft wing equipped with an engine, in which an aircraft flap with a noise reduction device according to a preferred embodiment of the present invention is shown.

[0020] Figure 2 is viewed from the lower wing surface of the aircraft flap Figure 1 of the enlarged three-dimensional schematic view of the aircraft flap, in which the arrangement of the noise reduction device in the aircraft flap is shown in a perspective form.

[0021] Figure 3 is viewed from the upper wing surface of the aircraft flap Figure 1 of the enlarged three-dimensional schematic view of the aircraft flap, in which the arrangement of the noise reduction device in the aircraft flap is shown in a perspective form.

[0022] Figure 4 is Figure 2 of the cross-sectional view of the aircraft flap, in which the second noise reduction structure is not shown.

[0023] List of Reference Numerals

[0024] 100 Aircraft flap

[0025] 101 Upper wing surface

[0026] 111 Outer surface

[0027] 102 Lower wing surface

[0028] 121 Outer surface

[0029] 103 Cavity

[0030] 104 Leading edge

[0031] 105 Trailing edge

[0032] 1 Noise reduction device

[0033] 2 First noise reduction structure

[0034] 21 Upper part

[0035] Lower part 22

[0036] 3. Second noise reduction structure

[0037] 4. Third noise reduction structure

[0038] 41. Noise reduction component

[0039] 200. Aircraft main wing

[0040] X spanwise direction

[0041] Y chordwise direction Detailed implementation manners

[0042] The following elaboration of the specific implementation manners of the present invention refers to the accompanying drawings, which show specific embodiments in which the present invention can be practiced. The embodiments are intended to describe all aspects of the present invention in sufficient detail to enable those skilled in the art to practice the present invention. Other embodiments can be utilized and changes can be made without departing from the scope of the present invention. Therefore, the following elaboration of the specific implementation manners should not be considered restrictive. The scope of the present invention is defined only by the appended claims and the full scope of equivalents covered by the claims. The same reference numerals are used to refer to the same or similar components in all the drawings and specific implementation manners.

[0043] As used herein, "front", "rear", "upper", and "lower" are relative orientation terms with respect to the working position of the aircraft flap 100 (as Figure 1 shown). Specifically, the component in front of the aircraft flap 100 is closer to the aircraft main wing 200 than the component at the rear, and the component above is above the component below in the working position as Figure 1 shown. The spanwise direction X refers to the direction parallel to the direction extending from the wing root to the wing tip of the aircraft main wing 200, and the chordwise direction Y is perpendicular to the spanwise direction X and refers to the direction extending from the leading edge 104 to the trailing edge 105 of the aircraft flap 100.

[0044] Figure 1 An aircraft wing equipped with an engine is schematically shown, in which the aircraft flap 100 with the noise reduction device 1 is shown, and the position where the noise reduction device 1 is located is generally shown. Specifically, the noise reduction device 1 is arranged in the area where the engine jet interference of the aircraft flap 100 is strong, and this area can be determined by unsteady fluid calculation. In this preferred embodiment, the noise reduction device 1 is shown as being arranged closer to the trailing edge 105 of the aircraft flap 100, but the present invention is not limited thereto, and it can also be arranged at other positions where the calculated engine jet interference is strong.

[0045] Figures 2 to 4Shows an aircraft flap 100 and a noise reduction device 1. Generally, the aircraft flap 100 includes an upper wing surface 101, a lower wing surface 102, and a cavity 103 formed by enclosing the upper wing surface 101 and the lower wing surface 102. In addition, the aircraft flap 100 also includes a leading edge 104 and a trailing edge 105 that are opposite to each other along the chordwise direction Y. The noise reduction device 1 of this preferred embodiment is arranged adjacent to the trailing edge 105.

[0046] The noise reduction device 1 includes a first noise reduction structure 2 having an upper portion 21 and a lower portion 22, a second noise reduction structure 3 filled between the upper portion 21 and the lower portion 22 of the first noise reduction structure 2, and a third noise reduction structure 4 including a plurality of noise reduction members 41 inserted from the first noise reduction structure 2 into the second noise reduction structure 3.

[0047] The first noise reduction structure 2 includes a porous structure such as a perforated plate, the upper portion 21 of which is embedded in the upper wing surface 101 of the aircraft flap 100, and the lower portion 22 of which is embedded in the lower wing surface 102 of the aircraft flap 100. Further, the upper portion 21 and the lower portion 22 are shaped to be flush with the outer surface 111 of the upper wing surface 101 and the outer surface 112 of the lower wing surface 102, respectively, so that the airfoil of the aircraft flap 100 is not changed by the first noise reduction structure 2, thereby avoiding the noise reduction device 1 from affecting the aerodynamic performance of the aircraft flap 100. Connecting members such as rivets or bolts can be used to fix the upper portion 21 and the lower portion 22 of the first noise reduction structure 2 to the surrounding upper wing surface 101 and lower wing surface 102, respectively, to ensure the connection strength. The perforated plate structure is stable, which is beneficial to firmly fixing the noise reduction device 1 in place on the aircraft flap 100, and it also has good noise reduction performance, with a relatively wide noise reduction frequency band. Combining it with other sound absorption structures can achieve a strong noise reduction effect. Such a porous structure with stable structure will not be structurally deformed due to the high-speed airflow flowing through during takeoff, landing, and flight, thereby affecting the aerodynamic performance of the aircraft flap 100.

[0048] The second noise reduction structure 3 includes a structure such as metal foam that can reduce high-frequency noise, which is arranged between the upper portion 21 and the lower portion 22 of the first noise reduction structure 2 and attached to the first noise reduction structure 2. Specifically, the second noise reduction structure 3 fills the portion of the cavity 103 of the aircraft flap 100 that is between the upper portion 21 and the lower portion 22 of the first noise reduction structure 2, and is attached to the upper portion 21 and the lower portion 22 in a manner such as bonding. In other words, the first noise reduction structure 2 sandwiches the second noise reduction structure 3 between its upper portion 21 and lower portion 22. Metal foam has excellent high-frequency noise reduction performance, and sandwiching the metal foam between two layers of stable perforated plates can ensure that the metal foam will not be accidentally displaced.

[0049] The third noise reduction structure 4 is as Figure 4As shown, it includes a plurality of noise reduction members 41 to form a superstructure, mainly used for reducing low-frequency noise. In this preferred embodiment, the third noise reduction structure 4 includes a plurality of partition plates. The noise reduction members 41 are arranged in a staggered manner in the circumferential direction Y in the second noise reduction structure 3. Figure 4 For the sake of clearly expressing the arrangement manner of the noise reduction members 41, the second noise reduction structure 3 is not shown. Specifically, one noise reduction member 41 extends downward from the upper part 21 of the first noise reduction structure 2 towards the lower part 22 and is inserted into the second noise reduction structure 3, but does not contact the lower part 22. The adjacent noise reduction member 41, on the contrary, extends upward from the lower part 22 of the first noise reduction structure 2 towards the upper part 21 and is inserted into the second noise reduction structure 3, but does not contact the upper part 21. According to this rule, a plurality of noise reduction members 41 are arranged in a staggered manner. When the engine jet noise enters the noise reduction device through the perforations on the surface of the first noise reduction structure 2, this arrangement of the plurality of noise reduction members 41 forces the sound waves to propagate through the gaps between the partition plates and the upper part 21 or the lower part 22 of the first noise reduction structure 2, extending the propagation path of the sound waves in the noise reduction device, contributing to the absorption of the low-frequency components of the jet installation noise, and improving the noise reduction bandwidth.

[0050] However, the present invention is not limited thereto. The plurality of noise reduction members 41 of the third noise reduction structure 4 can also be arranged to extend from the upper part 21 to the lower part 22 of the first noise reduction structure 2 at intervals in the circumferential direction Y, thereby forming a plurality of compartments. This compartment structure is also beneficial for reducing noise, especially for reducing low-frequency noise.

[0051] From Figures 1 to 3 It can be seen that the upper part 21 and the lower part 22 of the first noise reduction structure 2 in the preferred embodiment of the present invention are shaped as corresponding rectangles to each other. However, the present invention is not limited thereto. The upper part 21 and the lower part 22 of the first noise reduction structure 2 can be shaped into any suitable shape as long as it includes the region with strong engine jet interference obtained through calculation, and the shape is regular, conducive to manufacturing, and has little influence on the aerodynamic shape of the aircraft flap 100.

[0052] The detailed structural parameter setting logic for the perforated plate of the first noise reduction structure 2, the metal foam of the second noise reduction structure 3, and the multi-partition arrangement of the third noise reduction structure 4 is as follows:

[0053] a) Taking the aerodynamic performance as the constraint condition and the noise reduction performance as the optimization target, using wind tunnel tests or numerical simulation calculations to optimize the shape parameters of the perforated plate and the foam metal, including the aperture of the perforated plate, the hole pitch, and the porosity, flow resistance rate, tortuosity factor, etc. of the foam metal, to maximize the noise reduction effect on the premise of not losing too much aerodynamic performance;

[0054] b) Obtain the main frequency bands of the jet installation noise under the optimal shape parameters of the perforated plate and the metallic foam, determine the working frequency of the superstructure inside the flap, select the sample values of the superstructure shape design parameters, including the gap between the partitions, the thickness of the partitions, the spacing between the partitions, etc. Subsequently, calculate the noise transmission loss under this shape parameter based on the acoustic impedance model of the superstructure, and determine whether it meets the design requirements. If not, generate the next set of superstructure shape parameters and iterate until the required noise reduction effect is achieved.

[0055] The aircraft flap of the present invention uses a noise reduction device that integrates a first noise reduction structure with stable structure, a second noise reduction structure with excellent high-frequency noise reduction performance, and a third noise reduction structure with excellent low-frequency noise reduction performance. The noise reduction bandwidth is relatively wide, and this noise reduction device is arranged in the area where the engine jet interference is strong, so that it can effectively reduce the increased noise of the aircraft flap caused by the interference with the engine jet while ensuring the stable structure of the noise reduction device, and solves the problem in the prior art that the noise reduction material structure and the noise reduction performance that may be used on the aircraft flap cannot have both.

[0056] As used herein, the terms "comprising", "including", "having" or any other variant thereof are intended to cover non-exclusive inclusion. For example, a method, article or device comprising a series of elements is not necessarily limited to those elements, but may also include other elements not expressly listed or inherent to such method, article or device.

[0057] The present invention is not limited to the above embodiments, and the above embodiments are merely illustrative rather than restrictive. Those skilled in the art can make any possible changes and modifications under the inspiration of the present invention without departing from the purpose of the present invention and the scope protected by the claims. Therefore, all modifications, equivalent changes and decorations made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention fall within the protection scope defined by the claims of the present invention.

Claims

1. An aircraft flap, comprising: An upper wing surface and a lower wing surface opposite to each other, wherein the upper wing surface and the lower wing surface surround and form a cavity; as well as A noise reduction device, the noise reduction device is arranged in the cavity, comprising: a first noise reduction structure, the first noise reduction structure comprising an upper portion and a lower portion, wherein the upper portion is embedded in the upper wing surface and the lower portion is embedded in the lower wing surface; a second noise reduction structure disposed between the upper and lower portions of the first noise reduction structure and attached to the first noise reduction structure; and A third noise reduction structure is embedded in the second noise reduction structure.

2. The aircraft flap according to claim 1, characterized in that The noise reduction device is arranged in a region of the aircraft flap which strongly interferes with the engine jet.

3. The aircraft flap according to claim 1, characterized in that The first noise reduction structure includes a porous structure, the second noise reduction structure includes a high frequency noise reduction structure, and the third noise reduction structure includes a low frequency noise reduction structure.

4. The aircraft flap according to any one of claims 1 to 3, characterized in that An upper portion of the first noise reduction structure is shaped to be flush with an outer surface of the upper airfoil, and a lower portion of the first noise reduction structure is shaped to be flush with an outer surface of the lower airfoil.

5. The aircraft flap according to any one of claims 1 to 3, characterized in that The second noise reduction structure extends from the upper portion of the first noise reduction structure to the lower portion of the first noise reduction structure, filling a portion of the cavity between the upper portion and the lower portion of the first noise reduction structure.

6. The aircraft flap according to any one of claims 1 to 3, characterized in that The third noise reduction structure comprises a plurality of noise reduction members staggeredly arranged in the second noise reduction structure along the chord direction, Among them, one of the multiple noise reduction members extends from the upper part or the lower part of the first noise reduction structure toward the lower part or the upper part, while another adjacent noise reduction member extends from the lower part or the upper part of the first noise reduction structure toward the upper part or the lower part in the opposite direction.

7. The aircraft flap according to any one of claims 1 to 3, characterized in that The third noise reduction structure includes a plurality of noise reduction members, wherein each of the plurality of noise reduction members extends from an upper portion of the first noise reduction structure to a lower portion of the first noise reduction structure.

8. The aircraft flap according to claim 3, characterized in that: The porous structure includes a perforated plate, the high-frequency noise reduction structure includes foamed metal, and the low-frequency noise reduction structure includes a plurality of baffles.

9. The aircraft flap according to claim 1, characterized in that: The aircraft flap comprises a leading edge and a trailing edge opposite to each other in a chordwise direction, wherein the noise reduction device is arranged closer to the trailing edge.

10. The aircraft flap according to claim 1, characterized in that The upper portion and the lower portion of the first noise reduction structure of the noise reduction device are shaped as a rectangle.

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