CN216185999U

CN216185999U - Aircraft wing flap

Info

Publication number: CN216185999U
Application number: CN202122712308.7U
Authority: CN
Inventors: 张颖哲; 柏宝红; 林大楷
Original assignee: Commercial Aircraft Corp of China Ltd; Beijing Aeronautic Science and Technology Research Institute of COMAC
Current assignee: Commercial Aircraft Corp of China Ltd; Beijing Aeronautic Science and Technology Research Institute of COMAC
Priority date: 2021-11-08
Filing date: 2021-11-08
Publication date: 2022-04-05
Anticipated expiration: 2031-11-08

Abstract

The utility model relates to an aircraft flap, not comprising an actuating structure providing an air jet, comprising at least one lateral edge opening connecting one or more air passages, which extend through a first surface and a second surface of the flap, a first lateral edge opening being formed on the first surface and a second lateral edge opening being formed on the second surface, one of the first surface and the second surface being a lateral surface of the flap, one of the first lateral edge opening and the second lateral edge opening being a lateral surface opening. The flap provided by the utility model has a simple structure, can be applied to airplane noise reduction, reduces aerodynamic loss while reducing noise, and can also reduce pulsating pressure load on the local wall surface of the side edge of the flap so as to improve the safety of the airplane.

Description

Aircraft wing flap

Technical Field

The utility model relates to the field of aircraft high lift systems, in particular to an aircraft flap with a noise reduction structure.

Background

The external noise level of a large passenger plane is a core index of environmental protection and is also an important evaluation standard for airworthiness evidence obtaining. Noise airworthiness regulations of the international civil aviation organization stipulate noise control standards for approach and takeoff of aircraft. Since 12 months 2017, europe and the united states have begun to implement the fifth phase civil aircraft noise airworthiness regulation, which requires a further reduction in the cumulative noise margin by 7EPNdB over the fourth phase standard. The term is suitable for the model which applies for airworthiness qualification certificate 12 months and 31 days later in 2017, and provides more severe requirements for airworthiness evidence obtaining of C919 large passenger aircraft and CR929 remote wide-body passenger aircraft in China. Aircraft external noise is primarily from the engines and the aircraft airframe. The flap skirt is a significant source of aircraft body noise and is typical of flow sounding problems. The main functions of the airplane flap are to improve the low-speed characteristic of the airplane, improve the aerodynamic performance of the airplane during takeoff and landing and ensure the stability and safety of the airplane during takeoff and landing. However, when the aircraft flap is opened, strong aerodynamic noise radiation is generated at the flap side edge, and flap side edge noise is generated.

The main mechanisms of flap skirt noise are: because of the great pressure difference existing on the upper surface and the lower surface of the aircraft flap, a high-strength lateral edge double vortex structure is formed on the lateral edge of the flap, the self instability of the lateral edge double vortex structure and the interference and impact of the double vortex structure and the flap solid wall surface induce and generate strong unsteady surface pulsating pressure, the strong surface pulsating pressure can radiate noise outwards, and the noise is mainly concentrated in a high-frequency range; in addition, the conventional flap side edge is mostly a right-angled edge, so that sound scattering easily occurs with a double vortex flow structure, and very strong radiation noise is generated, and part of the noise is mainly concentrated in a low-frequency range.

The main idea of flap skirt noise control is to weaken the flap skirt vortex structures and to weaken the interaction between the vortex structures and the wall surface. Currently, there are mainly passive control techniques and active control techniques. Passive control techniques to reduce noise by changing and modifying the skirt configuration include (1) adding a porous material; (2) the side edge of the flap is provided with a fence (similar to a wingtip winglet), the side edge fence can increase the stability of a side edge shear layer, avoid the mutual interference of side edge vortex system structures and sharp side edges and delay the fusion of the vortex system structures; (3) the method adopts a flexible material configuration continuous molded line method to eliminate the side edge of the flap, so that the flap is smoothly connected with the main wing, thereby eliminating the shear vortex structure at the side edge, changing the discontinuity of the spanwise lift force at the side edge of the flap and fundamentally eliminating the noise of the side edge of the flap. The active control technique includes blowing high-speed air flow into the side edge flow field to blow vortex systems off the wall surface to reduce the noise intensity, but the method has limited noise reduction effect and complex structure, and needs additional energy. The prior art for controlling the noise of the side edge of the flap is still immature, and the further reduction of the whole noise of a large passenger plane is restricted.

The search of the prior art finds that the technology which is relatively close to the scheme provided by the utility model is as follows:

patent document 1: CN101454202A discloses a trailing edge flap for noise reduction, which is cut from the middle section structure of the outer edge of the trailing edge flap to form several parts that are not communicated with each other, so as to form an air passage between the upper and lower wing surfaces, thereby reducing the noise of the flap side edge. The large open area of this solution results in significant flow separation in the cruise air path, which results in high drag.

Patent document 2: 2020116272656 discloses a trailing edge flap in which one or more air passages that penetrate between the upper and lower wing surfaces of a flap body are formed in the midsection portion of the outer edge portion of the flap body, the air passages are open to the outside in the wing length direction, and porous media are filled in the air passages. However, the up-down through hole opening mode can cause a large amount of pneumatic loss, and the porous medium is easy to cause the blockage of the porous medium in the severe flying environment in the practical use of the airplane, so that the purpose of air flow passing through cannot be achieved, the control effect is greatly reduced, and the maintenance cost is increased.

Therefore, there is a need for an aircraft flap that has a simple structure and that reduces aerodynamic loss and cruise drag while reducing aerodynamic noise at the flap side edges.

SUMMERY OF THE UTILITY MODEL

The utility model provides an aircraft flap, which aims to solve the problems of high aerodynamic loss, high cruising resistance, complex structure and the like in the prior art.

An embodiment of the utility model provides an aircraft flap, comprising no actuating structure providing an air jet, characterized in that the aircraft flap comprises at least one lateral edge opening connecting one or more air passages; the air passageway extends through a first surface and a second surface of the flap, forming a first side edge opening on the first surface and a second side edge opening on the second surface; one of the first and second surfaces is a side surface of the flap and one of the first and second side edge openings is a side surface opening. The side edges comprise the flap side edges and/or regions close to the flap side edges. The flap side edge comprises the flap outer side edge and/or a position close to the flap outer side edge. Since the flap side edge vortex structures are mostly concentrated on the flap side surface, the flap side edge side surface is a main source area of noise sources, and the opening in the side surface can reduce the strength of the vortex structures, meaning that the opening effect is better in the side surface.

The flap is in an operating state, and the first surface pressure is greater than the second surface pressure. The working state comprises the situations of taking off, landing and the like which need to improve the lift force. The first surface has a higher pressure than the second surface in the pressure distribution, and the air passage extends through the first surface and the second surface of the flap, so that aerodynamic loss can be reduced while noise is reduced, and the influence on the lift force is smaller.

The first side edge opening has a cross-sectional area greater than a cross-sectional area of the second side edge opening. Since the first surface pressure is greater than the second surface and there is a pressure difference between the first surface and the second surface, the first side edge opening on the first surface forms an air suction groove, the second side edge opening on the second surface forms an air blowing groove, the air suction groove is an air inlet of air entering the air passage, and the air blowing groove is an air outlet of air flowing out of the air passage. The suction groove cross sectional area is greater than the gas blow groove cross sectional area, the suction groove can play stable effect to the high-pressure draught of first surface promptly high-pressure surface department, and the gas blow groove then can produce obvious strong efflux, strong efflux is just regional to the core of flap flank vortex system structure, consequently strong efflux can blow away flap flank vortex system structure from the flap surface better, weakens the interact of flap flank vortex system structure and wall simultaneously, also can dissipate flap flank vortex system structure more effectively.

The cross-sectional area of one of the side surface openings accounts for more than 1% of the total area of the side surface of the flap.

The sum of the cross-sectional areas of the side surface openings accounts for 5% to 30% of the total area of the side surfaces of the flap.

The sum of the cross-sectional areas of the second side edge openings accounts for 5% -20% of the sum of the cross-sectional areas of the first side edge openings, and the first side edge openings are the side surface openings.

The sum of the sectional areas of the first side edge openings is 5 to 15 times that of the second side edge openings, and the second side edge openings are the side surface openings. The noise reduction effect depends mainly on the airflow speed and flow rate in the air passage. Because the air passageway connects the high pressure region and the low pressure region, the pressure differential between the two regions determines the velocity of the air flow in the air passageway. The size of the air passage determines the flow rate. Therefore, the larger the size is, the better the noise reduction effect is, but the size is not too large, and the flap structure is damaged.

The plurality of air passages are not in communication with each other.

The first and second side edge openings are shaped differently.

The at least one side edge opening is located at the flap leading edge; the at least one side edge opening is located at the flap outboard edge leading edge. The flap leading edge comprises a flap side edge leading edge portion comprising the flap outer side edge leading edge and/or a portion proximate to the flap outer side edge leading edge. The side edge opening is arranged on the front edge of the side edge of the flap, and according to the flow structure of the side edge of the flap, the vortex structure of the side edge of the flap is generated from the front edge of the side edge of the flap and then continuously grows and becomes stronger in the downstream flow process. Therefore, the control vortex system structure generating source can achieve better control flap side edge flow structure, and further better control flap side edge noise.

The utility model discloses a beneficial effect:

the embodiment of the utility model selects the opening on the side surface of the flap, because the side surface plays a very important role in the generation and development processes of the vortex structure on the side edge of the flap, and does not penetrate through the upper surface and the lower surface of the flap, thereby reducing the aerodynamic loss while reducing the noise.

The embodiment of the utility model does not need an additional airflow control device and an airflow supply device, and has simple structure. In the takeoff or landing stage of the airplane, the side edge of the flap is opened, and the load on the side edge of the flap is relatively strong, so that the pressure difference between two sides of the air passage is large, and the noise reduction effect of the air passage is better. During the cruising stage of the airplane, the flap is retracted, the load on the lateral edge of the flap is smaller, and the pressure difference between two sides of the air passage is smaller, so the cruising resistance is small.

The air passage of the embodiment of the utility model does not need to be filled with porous media, because the porous media are easy to cause the blockage of the porous media in the severe flying environment in the practical use of an airplane, the aim of passing the airflow cannot be achieved, the control effect is greatly reduced, and the maintenance cost is increased.

The air passage of the utility model can not only reduce the noise of the side edge of the flap, but also weaken the pulsating pressure load on the local wall surface of the side edge of the flap, and the safety flight of the airplane can be influenced because the flap is buffeted due to the overlarge pressure load of the wall surface, and the structure of the flap can be damaged under serious conditions, so the utility model can improve the safety of the airplane.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below, and it is apparent that the drawings in the following description are only some embodiments of the present invention.

FIG. 1 is a schematic view of the structure of the upper and side surfaces of the outer edge of the flap of embodiment 1 of the present invention;

in fig. 1: 10-a flap; 13-upper surface; 11-side surface; 120-a suction slot; 130-air blowing grooves; 110-air blowing grooves;

FIG. 2 is a schematic view of the structure of the lower surface and the side surface of the outer edge of the flap in embodiment 1 of the present invention;

in fig. 2: 10-a flap; 15-lower surface; 11-side surface; 140-a suction slot; 110-air blowing grooves; 120-a suction slot;

FIG. 3 is a schematic cross-sectional view of the outer side edge of the flap of embodiment 1 of the present invention;

in fig. 3: 10-a flap; 15-lower surface; 11-side surface; 13-upper surface;

FIG. 4 is a schematic view of the outer edge of the flap of embodiment 2 of the present invention;

FIG. 5 is a comparison of the structure of the flap side edge of example 3 of the present invention with a conventional flap side edge;

FIG. 6 is a root mean square cloud of pulsating pressure between the side edges of the flap and the side edges of the plain flap of example 3 of the present invention;

FIG. 7 is a cloud of the average pressure distribution of the flap side edge versus the plain flap side edge of example 3 of the present invention;

fig. 8 is a noise spectrum diagram of the flap side edge and the normal flap side edge of embodiment 3 of the present invention, with the flap side edge being directly below the flap side edge as an observation point.

Detailed Description

Technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, however, it should be understood that the embodiments disclosed herein are merely typical examples of the present invention, and may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed manner, including employing various features disclosed herein and including features that may not be disclosed herein.

It should be noted that the directional references used herein to disclose the structure and action of the various parts of the disclosed embodiments, such as upper surface, lower surface, inward, outward, etc., are not absolute, but relative. These representations are suitable when the various parts of the disclosed embodiments are in the positions shown in the figures. If the position or frame of reference of the disclosed embodiments changes, these representations also change in accordance with the change in position or frame of reference of the disclosed embodiments.

The structure of an aircraft flap provided by an embodiment of the utility model will now be described with reference to the accompanying drawings, in which like reference numerals identify like elements.

An embodiment of the utility model provides an aircraft flap, comprising: a deployable flap 10, said flap 10 having an upper surface 13, a side surface 11 and a lower surface 15, and at least one side edge opening located near an outer edge of the flap, the side edge opening connecting an air passage extending through a first surface and a second surface of the flap, the first surface pressure being greater than the second surface pressure.

Example 1

An embodiment of the utility model provides an aircraft flap, and fig. 1 and 2 are schematic views of the outer edge portion of the flap of this embodiment. Since the air passage of the embodiment of the present invention connects the first surface and the second surface, the first surface pressure is greater than the second surface pressure, and the known flap lower surface pressure > flap side surface pressure > flap upper surface pressure, the air passage of the embodiment connects the lower surface and the side surface of the flap or connects the side surface and the upper surface of the flap, and there are two air passages in the preferred embodiment, one air passage connects the flap upper surface 13 and the side surface 11, the air blowing groove 130, i.e., the second side edge opening connecting the air passages, is formed on the flap upper surface 13, and the air suction groove 120, i.e., the first side edge opening connecting the air passage, is formed on the flap side surface 11; the other air passage connects the flap lower surface 15 and the side surface 11, an air suction groove 140, i.e., a first side edge opening connecting the air passage, is formed on the flap lower surface 15, an air blowing groove 110, i.e., a second side edge opening connecting the air passage, is formed on the flap side surface 11, the first side edge opening and/or the second side edge opening of the side surface, the upper surface and the lower surface are/is square in shape, and the flap outer side edge portion of this embodiment has a cross-sectional shape as shown in fig. 3. The air suction grooves 140 on the flap lower surface 15 and the air suction grooves 120 on the side surface 11 play a role in stabilizing high-pressure airflow at the flap lower surface 15 and the side surface 11, and reduce the strength of the flap side edge vortex system structure. In addition, strong jet flow can be formed at the positions of the air blowing grooves 130 on the upper surface 13 of the flap and the air blowing grooves 110 on the side surface 11 of the flap, so that the dissipation of the flap side edge vortex structure is enhanced, the flap side edge vortex structure can be blown away from the flap side edge surface, and the interaction between the flap side edge vortex structure and the flap side edge surface is reduced. Finally, the effect of reducing the noise of the side edge of the flap is achieved.

Example 2

An embodiment of the utility model provides an aircraft flap, and FIG. 4 is a schematic view of the outboard edge portion of this embodiment having an air passage extending through the flap connecting the flap side and lower surfaces, the side edge opening being square in shape on the side and lower surfaces.

Example 3

A particular embodiment of the utility model provides an aircraft flap having an air passage connecting a high pressure surface and a low pressure surface, in this embodiment the air passage connecting a lower flap surface and a side surface, a second side opening connecting the side surfaces of the air passage being elongate in shape and a first side opening of the lower surface being rectangular in shape. FIG. 5 is a comparison of the geometry of a plain flap side edge and a flap side edge of example 3. The flap of the embodiment 3 is subjected to noise reduction effect evaluation by adopting a numerical simulation means, wherein figure 6 is a root mean square cloud chart of pulsating pressure of the side edge of the plain flap and the side edge of the flap of the embodiment 3, and figure 7 is a cloud chart of average pressure distribution of the side edge of the plain flap and the side edge of the flap of the embodiment 3. As can be seen from fig. 6 and 7, the air passage connecting the lower surface and the side surface of the flap side edge significantly changes the flap surface pulsating pressure distribution, and the pulsating pressure of the flap side edge of example 3 is significantly suppressed, which not only reduces the load of the flap side edge, but also reduces the noise radiated from the flap side edge, and the air passage also reduces the pressure amplitude on the flap side edge trailing edge. Far-field flap skirt noise is also reduced. Fig. 8 shows noise spectra of the plain flap side edge and the flap side edge of example 3, which are observed from the point just below the flap side edge. It can be seen that the flap skirt of example 3 significantly reduces flap skirt noise, especially in the low frequency range by about 5 dB.

The utility model is not limited to the number of air passages, but too many air passages affect the flap structure, so in the embodiment provided by the utility model the number of air passages is more than 1, less than 4, preferably 2. The shape of the opening of the side edge opening on the side surface or the upper surface or the lower surface can be any, including square, round and strip. The cross-sectional area of one of the side surface openings accounts for more than 1% of the total area of the side surface of the flap. The sum of the cross-sectional areas of the side surface openings accounts for 5% to 30% of the total area of the side surfaces of the flap. The sum of the cross-sectional areas of the second side edge openings accounts for 5% -20% of the sum of the cross-sectional areas of the first side edge openings, and the first side edge openings are the side surface openings. The sum of the sectional areas of the first side edge openings is 5 to 15 times that of the second side edge openings, and the second side edge openings are the side surface openings.

The technical contents and technical features of the present invention have been disclosed above, and the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit the same. The flap provided by the utility model can reduce the noise and the aerodynamic loss at the same time, does not need an additional airflow control device and an airflow supply device, has a simple structure, can reduce the noise of the flap side edge, can weaken the pulsating pressure load on the local wall surface of the flap side edge, and improves the safety of the airplane.

Claims

1. An aircraft flap, comprising no actuating structure providing an air jet, characterized in that it comprises at least one lateral edge opening connecting one or more air passages; the air passageway extends through a first surface and a second surface of the flap, forming a first side edge opening on the first surface and a second side edge opening on the second surface; one of the first surface and the second surface is a side surface of a flap; one of the first side edge opening and the second side edge opening is a side surface opening.

2. The aircraft flap of claim 1 wherein the first surface pressure is greater than the second surface pressure in the flap operating condition.

3. The aircraft flap of claim 1 wherein the first side edge opening has a cross-sectional area greater than a cross-sectional area of the second side edge opening.

4. The aircraft flap of claim 1 wherein the cross-sectional area of one of the side surface openings accounts for more than 1% of the total area of the side surface of the flap.

5. The aircraft flap of claim 1 wherein the sum of the cross-sectional areas of the side surface openings is between 5% and 30% of the total area of the side surface of the flap.

6. The aircraft flap of claim 1 wherein the sum of the second side edge opening cross-sectional areas is from 5% to 20% of the sum of the first side edge opening cross-sectional areas; the first side edge opening is the side surface opening.

7. The aircraft flap of claim 1 wherein the sum of the first side edge opening cross-sectional areas is 5 to 15 times the sum of the second side edge opening cross-sectional areas; the second side edge opening is the side surface opening.

8. The aircraft flap of claim 1 wherein the first and second side edge openings are shaped differently.

9. The aircraft flap of claim 1 wherein the at least one side edge opening is located at a flap leading edge.