CN103010459A

CN103010459A - Method for reducing pneumatic noise of leading edge slat based on trailing edge micro-perforation

Info

Publication number: CN103010459A
Application number: CN2012105318736A
Authority: CN
Inventors: 刘沛清; 李芳丽; 屈秋林; 郭昊; 田云; 刘晓斌
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2012-12-11
Filing date: 2012-12-11
Publication date: 2013-04-03
Anticipated expiration: 2032-12-11
Also published as: CN103010459B

Abstract

The invention discloses a method for reducing the pneumatic noise of a leading edge slat based on trailing edge micro-perforation. The method particularly comprises the steps as follows: setting a row of small holes at equal intervals in the wing unfolding direction at the trailing edge of the leading edge slat, wherein the perforation rate of the small holes in the unfolding direction is 2%, namely a line segment is made in the slat unfolding direction through the center of the small holes and the length of the line segment is the thickness of the slat in the unfolding direction; the sum of the lengths of all the small holes on the line segment is 2% of the whole thickness of the slat in the unfolding direction; the diameters of the small holes are 0.8-1 mm; and the distance between the center of the small holes and the trailing edge is 3-5 mm. According to the method, part of energy of sound waves is consumed in the small holes, a small amount of air stream on the lower surface of the slat flows to the upper surface of the slat through the small holes due to the pressure difference of the upper surface and the lower surface, and the vortex-shedding behavior of the trailing edge is influenced by locally changing the flow direction of the air stream in front of the trailing edge, so that the purpose of reducing the high-frequency sharp-frequency pneumatic noise generated by the slat is achieved, the pneumatic force is guaranteed to be not influenced basically at the same time; and the method is convenient to realize in engineering application.

Description

A kind of method that reduces the leading edge slat aerodynamics noise based on the trailing edge micropunch

Technical field

The present invention relates to a kind of method based on trailing edge micropunch reduction leading edge slat aerodynamics noise, belong to aviation engine body noise technical field.

Background technology

Along with the development of society and the progress of industrial technology, people have proposed more and more stricter environmental demands to Civil Aviation Industry.International Civil Aviation Organization has formulated the recommended standard of aircraft noise certification, and the U.S., Europe etc. has formulated a series of aircraft noise air worthiness regulations based on this, and the seating plane noise level is limited.These are undoubtedly huge challenge for the large-scale seating plane that China is developing, can noise level become it and obtain airworthiness certificate and following occupy one of key factor of one seat at world's aviation field.

Modern large-scale civil aircraft is in the take-off and landing stage, and after considering lift-rising effect and mechanism complexity, three sections wing formulas that generally adopt reach the lift-rising effect.Wherein, high lift device comprises leading edge slat and trailing edge flap.Fig. 1 has shown that the wing of three sections wing configurations forms, and comprises leading edge slat 1,

main wing

2 and 3 three parts of trailing edge flap.

Nowadays, take off and the landing stage at large-scale civil aircraft, along with motor noise reduces gradually, engine body noise is dominate gradually, and its noise source comprises aircraft high lift device and alighting gear.The high lift device aerodynamics noise mainly is comprised of leading edge slat aerodynamics noise and trailing edge flap side source aerodynamics noise.Flight test is consistent with wind tunnel experiment to be shown, in the aircraft landing stage, the leading edge slat aerodynamics noise can not be ignored.

Leading edge slat aerodynamics noise frequency spectrum is typical broadband noise spectrum, is comprising the single-tone noise of different frequency therebetween.Wherein, in the high frequency aerodynamics noise forms, obvious spike appears in the noise pattern.For the appearance of high frequency aerodynamics noise kurtosis, nowadays generally owing to the behavior of slat trailing edge vortex shedding.Therefore, changing the behavior of slat trailing edge vortex shedding will inevitably exert an influence to the high frequency aerodynamics noise.

Summary of the invention

To the objective of the invention is in order addressing the above problem, to propose a kind of method that reduces the leading edge slat aerodynamics noise based on the trailing edge micropunch.

A kind of method based on trailing edge micropunch reduction leading edge slat aerodynamics noise is specially: at the trailing edge place of leading edge slat, along the wing exhibition to row's aperture, spaced set between the aperture are set.

The exhibition of described aperture is 2% to punching rate, namely does a line segment along the slat exhibition to direction by the aperture center, line segment length be the slat exhibition to thickness, wherein, all hole diameters occupied length and be that whole exhibition is to 2% of thickness on this line segment.

Described hole diameter is 0.8 ~ 1mm, and the distance of aperture center and trailing edge is 3 ~ 5mm.

The invention has the advantages that:

(1) the present invention is by arranging aperture along exhibition to getting through one near the leading edge slat trailing edge, because slat upper and lower surface pressure reduction, so that a small amount of air-flow of lower surface flows to upper surface by aperture, the air current flow before the local change trailing edge, and then affect the behavior of trailing edge vortex shedding.

(2) among the present invention not only sound wave in aperture, can consume portion of energy, and mainly reach the sharp frequently purpose of aerodynamics noise of high frequency that reduction is produced by slat by changing the behavior of slat trailing edge vortex shedding, guarantee that simultaneously aerodynamic force is substantially unaffected, and be convenient to realize in the engineering application.

Description of drawings

Fig. 1 is three sections wing mechanism scheme drawings of the prior art;

Fig. 2 is near the aperture scheme drawing the slat trailing edge of the present invention;

Fig. 3 a is that wing exhibition of the present invention is to the hole knockout overall schematic;

The local enlarged diagram of Fig. 3 b Fig. 3 a.

Among the figure: the 1-leading edge slat; The 2-main wing; The 3-trailing edge flap; The 4-aperture.

The specific embodiment

The present invention is described in further detail below in conjunction with drawings and Examples.

The present invention is a kind of method based on trailing edge micropunch reduction leading edge slat aerodynamics noise, is specially: at the trailing edge place of leading edge slat 1, along the wing exhibition to row's aperture 4, spaced set between the aperture 4 are set.

Aperture 4 diameters are 0.8 ~ 1mm, the distance of aperture center and trailing edge is 3 ~ 5mm, exhibition is 2% to punching rate, namely do a line segment along the slat exhibition to direction by aperture 4 centers, line segment length is that the slat exhibition is to thickness, wherein, all aperture 4 diameters occupied length and be that whole exhibition is to 2% of thickness on this line segment.

As shown in Figure 2, near the trailing edge of leading edge slat 1, along the wing exhibition to getting through row's aperture 4, because pressure reduction can be so that a small amount of air-flow of leading edge slat 1 lower surface flows to the upper surface of leading edge slat 1 by aperture 4, air current flow before the local change trailing edge, and then affect the behavior of trailing edge vortex shedding.Sound wave can consume portion of energy in aperture 4, and the consumption of trailing edge vortex shedding energy also can increase, and reaches thus to reduce the frequently purpose of aerodynamics noise of the high frequency point that produced by leading edge slat 1.In addition, because punch position is very near apart from leading edge slat 1 trailing edge, and the position is very little to the contribution of aerodynamic force near leading edge slat 1 trailing edge, and on the less basis of control punching rate, is to guarantee that aerodynamic force is substantially impregnable by the mode of getting through aperture 4 noise reductions.And, punch aperture 4 and be convenient to realize in the engineering application.

Embodiment:

If leading edge slat 1 trailing edge thickness is 4mm, the wing exhibition is 600mm to thickness.Concrete exhibition is seen Fig. 3 a to hole knockout, and getting aperture 4 diameters is 1mm, per two aperture 4 centers be spaced apart 53mm, altogether 12 apertures 4.Fig. 3 b is the part punching enlarged drawing of Fig. 3 a, has shown position and the size of edge aperture 4, and the distance of aperture 4 centers and trailing edge is 4mm, is 8mm with opening up extrorse distance.The punching rate that obtains thus is 2%.

Invention is based near the method for the reduction leading edge slat aerodynamics noise of boring a hole large-scale civil aircraft leading edge slat trailing edge, guaranteeing on the substantially impregnable basis of aerodynamic force, can reach the purpose that reduces the high frequency point frequency aerodynamics noise that is produced by slat, and the method is convenient to realize in the engineering application.

Claims

1. the method based on trailing edge micropunch reduction leading edge slat aerodynamics noise is specially: at the trailing edge place of leading edge slat, along the wing exhibition to row's aperture, spaced set between the aperture are set.

2. a kind of method that reduces the leading edge slat aerodynamics noise based on the trailing edge micropunch according to claim 1, described aperture exhibition is 2% to punching rate, namely do a line segment along the slat exhibition to direction by the aperture center, line segment length is that the slat exhibition is to thickness, wherein, all hole diameters occupied length and be that whole exhibition is to 2% of thickness on this line segment.

3. according to claim 1 or 2 describedly a kind ofly reduce the methods of leading edge slat aerodynamics noise based on the trailing edge micropunch, described hole diameter is 0.8 ~ 1mm, and the distance of aperture center and trailing edge is 3 ~ 5mm.