CN105857576A - Noise-reduction slat structure based on jet-flow opening - Google Patents
Noise-reduction slat structure based on jet-flow opening Download PDFInfo
- Publication number
- CN105857576A CN105857576A CN201610124253.9A CN201610124253A CN105857576A CN 105857576 A CN105857576 A CN 105857576A CN 201610124253 A CN201610124253 A CN 201610124253A CN 105857576 A CN105857576 A CN 105857576A
- Authority
- CN
- China
- Prior art keywords
- slat
- jet
- flow
- jet flow
- noise reduction
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C9/00—Adjustable control surfaces or members, e.g. rudders
- B64C9/38—Jet flaps
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C21/00—Influencing air flow over aircraft surfaces by affecting boundary layer flow
- B64C21/02—Influencing air flow over aircraft surfaces by affecting boundary layer flow by use of slot, ducts, porous areas or the like
- B64C21/04—Influencing air flow over aircraft surfaces by affecting boundary layer flow by use of slot, ducts, porous areas or the like for blowing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C2230/00—Boundary layer controls
- B64C2230/14—Boundary layer controls achieving noise reductions
Landscapes
- Engineering & Computer Science (AREA)
- Aviation & Aerospace Engineering (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
Abstract
A noise-reduction slat structure based on a jet-flow opening includes the jet-flow opening and a slat, wherein the jet-flow opening is arranged on the upper surface or the lower surface of the front edge of the slat, the jet-flow opening is slit-shaped, square or round, and the distance between the jet-flow opening and the front edge of the slat is 1-3% of the slat length. The noise-reduction slat structure has the advantages of simple structure and reasonable design, can effectively reduce the noise generated by the slat, especially low-frequency noise.
Description
Technical field
The present invention relates to the technology of a kind of aerospace field, a kind of noise reduction slat structure based on jet flow opening.
Background technology
Aerodynamic noise is one of key issue in airliner development process, and its aerodynamic noise source specifically includes that electromotor, increasing
Rise device, undercarriage, dynamical system and body.
Taking off or landing phases at passenger plane, high lift device expansion can produce stronger aerodynamic noise, and wherein slat noise is lift-rising
The key component of system noise.When slat launches, forming blunt form and reduce passage between slat and main wing, air-flow is subtracting
Accelerate in contracting passage to suppress the flow separation of main wing suction surface, thus obtain and preferably rise resistance performance.Yet with slat and master
The discontinuous transition of the wing, air-flow separates in slat leading edge and forms shear layer, and shear layer is instable at Kelvin-Helmholtz
Effect is lower produces large scale eddy architecture, and final shear layer clashes into slat lower surface and produces the turbulence pulsation of high intensity, thus lures
The raw low-frequency noise of artificial deliviery.It addition, the air-flow mixing of slat upper and lower surface and shearing are also the generation mechanisms of slat noise medium-high frequency part.
Existing slat noise reduction technology specifically includes that layout sound lining and ribbon structure, slat leading edge saw in slat implant, cavity
Tooth.But the noise reduction of these technology is limited, compares active control technology and lack motility, and unadjustable to realize optimum fall
Make an uproar effect.
Injection is a kind of active Flow Control technology, utilizes the injection of local high-energy fluid and the boundary region of Interference Flow or cut
Cut the vortex structures evolution in downstream and development in layer, impact flowing, thus realize flowing or noise control effect.Injection exists
Delay boundary layer flow separation, wake management, aircraft power to have with the aspect such as Torque Control, turbomachine noise reduction preferably should
With.
Through the retrieval of prior art is found, Chinese patent literature CN103010459A, publication date 2013.4.3, open
A kind of method reducing leading edge slat aerodynamic noise based on trailing edge micropunch, at the trailing edge of leading edge slat, opens up to setting along wing
One row's aperture, spaced set between aperture；Described aperture exhibition is 2% to punching rate, i.e. by small hole center along slat exhibition to
A line segment is done in direction, line segment length be slat exhibition to thickness, wherein: length that all hole diameters are occupied on this line segment and be
Whole exhibition is to the 2% of thickness；Described hole diameter is 0.8～1mm, and small hole center is 3～5mm with the distance of trailing edge.But should
Air current flow before technology only local change trailing edge, affects trailing edge vortex shedding behavior, but cannot solve the noise produced when slat launches
Problem.
Summary of the invention
The present invention is directed to deficiencies of the prior art, propose a kind of noise reduction slat structure based on jet flow opening, by
Slat leading edge arranges jet flow opening, and jet flow sprays from jet flow opening with flow in certain direction, belongs to noise impedance technology, with
Disturb slat leading edge shear layer, weaken the large-scale vortex structure effect of impact with slat wall, it is achieved slat noise is greatly reduced.
The present invention is achieved by the following technical solutions:
The present invention includes: jet flow opening and slat, wherein: jet flow opening is arranged at upper surface or the lower surface of slat leading edge.
The jet direction of the jet flow opening being arranged at slat upper surface is 45 °～90 ° with slat wall angle, dimensionless jet flow flow
Coefficient is: Cμ=0.001～0.005；The jet direction of the jet flow opening being arranged at slat lower surface is 0 °～45 ° with carrying out flow path direction angle,
Dimensionless jet flow discharge coefficient is: Cμ=0.002～0.015.
Described jet outlets and distance is slat chord length the 1～3% of slat leading edge.
The shape of described jet outlets includes: bar slit, square or circular.
The length of described bar slit jet outlets is opened up to equivalently-sized with slat, and width is the 1.5～2% of slat chord length.
Described square jet outlets is opened up to being equally spaced along slat, and the length of side is the 1.5～2% of slat chord length.
Described circular jetting flow export is opened up to being equally spaced along slat, the 1.5～2% of a diameter of slat chord length.
Described jet flow is stable state jet flow or pulsed jet.
The producing method of described jet flow includes: external air source is blown or without external air source zero mass jet flow.
Described external air source is blown and is referred to: from electromotor or air accumulator, bleed blows out through gas off-take.
The described jet flow of zero mass without external air source realizes by using synthetic jet activator.
Described synthetic jet activator includes but not limited to: piezoelectric film vibration type, PVDF membrane vibration type, piston shake
Dynamic formula, shape memory alloy make dynamic formula or acoustically-driven formula.
Technique effect
Compared with prior art, the present invention uses noise impedance technology, arranges jet flow opening in slat leading edge surface, interference
Slat leading edge shear layer, weaken the effect of impact of large-scale vortex structure and slat wall, it is achieved the purpose of slat noise is greatly reduced,
Especially low-frequency noise.
Accompanying drawing explanation
Fig. 1 is schematic diagram of the present invention；
In figure: (a) is embodiment 1, (b) is embodiment 2；
Fig. 2 is noise spectrum schematic diagram before and after jet flow of the present invention；
In figure: (a) is embodiment 1, (b) is embodiment 2；
Fig. 3 is embodiment 1 schematic diagram；
Fig. 4 is embodiment 2 schematic diagram；
In figure: 1 is main wing, 2 is slat, and 3 is jet flow opening.
Detailed description of the invention
Elaborating embodiments of the invention below, the present embodiment is implemented under premised on technical solution of the present invention,
Give detailed embodiment and concrete operating process, but protection scope of the present invention is not limited to following embodiment.
Embodiment 1
As shown in Fig. 1 (a), the present embodiment includes: main wing 1, jet flow opening 3 and slat 2, wherein: jet flow opening 3 is arranged
In upper surface the jet flow of slat 2 leading edge, slat 2 is connected with main wing 1.
Described jet direction and slat 2 wall angle are 45 °～90 °.
The dimensionless jet flow discharge coefficient of described jet flow opening 3 is: Cμ=0.001～0.005.
Described dimensionless jet flow flow coefficient Cμ=2d/c (ujet/u∞)2, wherein: d is the width of jet outlets 3, c is
Main wing 1 chord length under cruising condition, u∞For speed of incoming flow, ujetFor effluxvelocity.
As shown in Fig. 2 (a), slat 2 leading edge upper surface is respectively adopted Cμ=2.43e-3 and CμBefore and after the jet flow of=4.32e-3,
By the noise pattern at 3.5 times of chord lengths below the numerical computations acquisition main wing 1 of hydrodynamics and acoustics.As can be seen from Figure,
After jet flow, low-frequency noise and high-frequency noise the most substantially reduce.
The jet flow of described slat 2 leading edge upper surface can lift free shear layer, makes free shear layer at slat 2 cavity wall
Attachment point moves to slat 2 trailing edge, reduces energy and velocity fluctuation after the flowing mixing of slat 2 upper and lower surface, reduces high-frequency noise；
Free shear layer self character changes simultaneously, and vortex structures is limited in free shear layer, hitting of free shear layer and wall
The degree of hitting weakens, and the low-frequency noise that the high intensity turbulent pulsation of knockout process induction produces is lowered.
As it is shown on figure 3, described jet outlets 3 and distance is slat 2 chord length the 2% of slat 2 leading edge.
Described jet outlets 3 be shaped as square.
Described jet outlets 3 is opened up to being equally spaced along slat 2, and the length of side is the 2% of slat 2 chord length.
Described jet flow is without external air source zero mass jet flow.
The described jet flow of zero mass without external air source is realized by synthetic jet activator.
Described synthetic jet activator is piezoelectric film vibration type.
When passenger plane landing, high lift device launches, and jet flow passes through the jet flow opening 3 on slat 2 in a certain direction according to specifying work
Make state and flow ejection, affect slat 2 noise generation mechanism by vortex dynamics in changing slat 2 cavity, thus realize noise reduction
Purpose；When passenger plane enters cruising condition, high lift device is packed up, and the flow-jetting function of jet flow opening 3 is closed.
Embodiment 2
As shown in Fig. 1 (b), the present embodiment includes: main wing 1, jet flow opening 3 and slat 2, wherein: jet flow opening 3 is arranged
In lower surface the jet flow of slat 2 leading edge, slat 2 is connected with main wing 1.
Described jet direction is 0 °～45 ° with carrying out flow path direction angle.
The dimensionless jet flow discharge coefficient of described jet flow opening 3 is: Cμ=0.002～0.015.
Described dimensionless jet flow flow coefficient CμIt is defined as: Cμ=2d/c (ujet/u∞)2, wherein: d is jet outlets 3
Width, c is main wing 1 chord length under cruising condition, u∞For speed of incoming flow, ujetFor effluxvelocity.
As shown in Fig. 2 (b), slat 2 leading edge lower surface is respectively adopted Cμ=2.43e-3 and CμBefore and after the jet flow of=4.32e-3,
By the noise pattern at 3.5 times of chord lengths below the numerical computations acquisition main wing 1 of hydrodynamics and acoustics.As can be seen from Figure,
After jet flow, in the range of 0～0.75kHz, low-frequency noise reduces, and front 4 narrow-band noises reduce the most to some extent；And about
At 3.5kHz, jet flow introduces first new narrow-band noise, introduces second new narrow-band noise, but make an uproar generally at about 8kHz
Sound still reduces.
The jet flow of described slat 2 leading edge lower surface can change the large scale eddy architecture of free shear layer, makes free shear layer
Becoming discrete vortex form after leaving slat 2 leading edge tip, discrete vortex intensity, size and unstability are all remarkably decreased, therefore certainly
Being weakened with collision with wall degree by shear layer, additionally, the flow behavior of cavity recirculating zone also changes, recirculating zone width diminishes,
Back-flow velocity reduces, and acoustic feedback mechanism is suppressed, and therefore low-frequency noise is lowered.
As shown in Figure 4, described jet outlets 3 and distance is slat 2 chord length the 2% of slat 2 leading edge.
Described jet outlets 3 be shaped as bar slit.
The length of described bar slit jet outlets 3 is opened up to equivalently-sized with slat 2, and width is the 2% of slat 2 chord length.
The producing method of described jet flow is that external air source is blown.
Described external air source is blown and is referred to: from electromotor or air accumulator, bleed blows out through gas off-take.
When passenger plane landing, high lift device launches, and jet flow passes through the jet flow opening 3 on slat 2 in a certain direction according to specifying work
Make state and flow ejection, affect slat 2 noise generation mechanism by vortex dynamics in changing slat 2 cavity, thus realize noise reduction
Purpose；When passenger plane enters cruising condition, high lift device is packed up, and the flow-jetting function of jet flow opening 3 is closed.
The present embodiment can arrange probe in detecting pressure fluctuation at slat 2 trailing edge and carry out jet flow amount closed loop control according to testing result.
Claims (8)
1. a noise reduction slat structure based on jet flow opening, it is characterised in that including: jet flow opening and slat, wherein: jet flow
Opening is arranged at upper surface or the lower surface of slat leading edge；
Jet direction and the slat wall angle of the jet flow opening being arranged at slat upper surface are 45 °～90 °, dimensionless jet flow flow system
Number is: Cμ=0.001～0.005；
The jet direction of the jet flow opening being arranged at slat lower surface is 0 °～45 ° with carrying out flow path direction angle, dimensionless jet flow discharge coefficient
For: Cμ=0.002～0.015.
Noise reduction slat the most according to claim 1, is characterized in that, described jet outlets is seam with the distance of slat leading edge
The 1～3% of chord-length.
Noise reduction slat the most according to claim 1, is characterized in that, described dimensionless jet flow flow coefficient Cμ=
2d/c(ujet/u∞)2, wherein: d is the width of jet outlets, c is the main wing chord length under cruising condition, u∞For speed of incoming flow, ujetFor
Effluxvelocity.
4. according to the noise reduction slat described in any of the above-described claim, it is characterized in that, the shape of described jet outlets includes: bar stitches
Shape, square or circular.
Noise reduction slat the most according to claim 4, is characterized in that, the length of described bar slit jet outlets and slat exhibition
To equivalently-sized, width is the 1.5～2% of slat chord length.
Noise reduction slat the most according to claim 4, is characterized in that, described square jet outlets is opened up to equidistantly along slat
Distribution, the length of side is the 1.5～2% of slat chord length.
Noise reduction slat the most according to claim 4, is characterized in that, described circular jetting flow export divides along slat exhibition to equidistant
Cloth, the 1.5～2% of a diameter of slat chord length.
8. according to the noise reduction slat described in any of the above-described claim, it is characterized in that, described jet flow is stable state jet flow or pulsed jet.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610124253.9A CN105857576A (en) | 2016-03-04 | 2016-03-04 | Noise-reduction slat structure based on jet-flow opening |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610124253.9A CN105857576A (en) | 2016-03-04 | 2016-03-04 | Noise-reduction slat structure based on jet-flow opening |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN105857576A true CN105857576A (en) | 2016-08-17 |
Family
ID=56625248
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610124253.9A Pending CN105857576A (en) | 2016-03-04 | 2016-03-04 | Noise-reduction slat structure based on jet-flow opening |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105857576A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111688890A (en) * | 2020-06-23 | 2020-09-22 | 西北工业大学 | Closed-loop active flow control device of underwater glider based on synthetic jet |
| CN112623196A (en) * | 2020-12-29 | 2021-04-09 | 中国航空工业集团公司西安飞机设计研究所 | Cavity noise control method |
| US11591068B2 (en) | 2019-06-10 | 2023-02-28 | Bombardier Inc. | Wing assembly with slats and aircraft |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3831886A (en) * | 1973-01-26 | 1974-08-27 | Lockheed Aircraft Corp | Airfoil with extendible and retractable leading edge |
| US3917193A (en) * | 1974-01-21 | 1975-11-04 | Boeing Co | Boundary layer control and anti-icing apparatus for an aircraft wing |
| US4326686A (en) * | 1980-02-15 | 1982-04-27 | Runge Thomas M | Fan jet engine bypass air delivery system for blown wing aircraft lift augmentation device |
| US4802642A (en) * | 1986-10-14 | 1989-02-07 | The Boeing Company | Control of laminar flow in fluids by means of acoustic energy |
| US20120187254A1 (en) * | 2011-01-26 | 2012-07-26 | Wollaston Timothy | Aircraft slat assembly with anti-icing system |
-
2016
- 2016-03-04 CN CN201610124253.9A patent/CN105857576A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3831886A (en) * | 1973-01-26 | 1974-08-27 | Lockheed Aircraft Corp | Airfoil with extendible and retractable leading edge |
| US3917193A (en) * | 1974-01-21 | 1975-11-04 | Boeing Co | Boundary layer control and anti-icing apparatus for an aircraft wing |
| US4326686A (en) * | 1980-02-15 | 1982-04-27 | Runge Thomas M | Fan jet engine bypass air delivery system for blown wing aircraft lift augmentation device |
| US4802642A (en) * | 1986-10-14 | 1989-02-07 | The Boeing Company | Control of laminar flow in fluids by means of acoustic energy |
| US20120187254A1 (en) * | 2011-01-26 | 2012-07-26 | Wollaston Timothy | Aircraft slat assembly with anti-icing system |
Non-Patent Citations (2)
| Title |
|---|
| 鲍国华: "《风洞特种实验》", 31 May 1990, 西北工业大学出版社 * |
| 黄华: "基于前缘射流的缝翼噪声控制研究", 《中国优秀硕士学位论文全文数据库工程科技Ⅱ辑》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11591068B2 (en) | 2019-06-10 | 2023-02-28 | Bombardier Inc. | Wing assembly with slats and aircraft |
| CN111688890A (en) * | 2020-06-23 | 2020-09-22 | 西北工业大学 | Closed-loop active flow control device of underwater glider based on synthetic jet |
| CN112623196A (en) * | 2020-12-29 | 2021-04-09 | 中国航空工业集团公司西安飞机设计研究所 | Cavity noise control method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Gregory et al. | A review of fluidic oscillator development and application for flow control | |
| CN108001669B (en) | Leading edge slat noise suppression method based on zero-mass jet control | |
| CN111929026B (en) | Low-frequency pressure pulsation suppression method for wind tunnel 3/4 opening test section | |
| US10358208B2 (en) | Hybrid flow control method for simple hinged flap high-lift system | |
| CN106151113B (en) | A kind of self-loopa multi stage axial flow compressor | |
| Pandey et al. | Numerical modeling of internal flow in a fluidic oscillator | |
| Liu et al. | Wake development of airfoils with serrated trailing edges | |
| CN103835810B (en) | Acoustic liner for air-inlet nacelle of aircraft engine and aircraft engine | |
| Hong | Effectiveness of micro synthetic jet actuator enhanced by flow instability in controlling laminar separation caused by adverse pressure gradient | |
| CN105857576A (en) | Noise-reduction slat structure based on jet-flow opening | |
| CN113859515A (en) | Aircraft wing flap | |
| Hossain et al. | Enhancement of aerodynamic properties of an airfoil by co flow jet (CFJ) flow | |
| CN106873647A (en) | A kind of array variable element jet flow flow control method based on zero-net-mass-flux jet | |
| CN107054673A (en) | It is a kind of to synthesize dual-jet driver and hypersonic flow flowing control method from maintenance | |
| CN216185999U (en) | Aircraft wing flap | |
| Mishra et al. | Numerical investigation of a finite wing section with a bleed hole allowing boundary layer suction | |
| Zhao et al. | Rectangular cavity flow noise suppression using chevron treatment to the front edge at subsonic speeds | |
| Zaman et al. | Synthetic Jets in Cross-Flow. Part I: Round Jet | |
| US9500161B2 (en) | Nozzle, structural element, and method of producing a nozzle | |
| Itsariyapinyo et al. | NACA0015 circulation control airfoil using synthetic jets at low angles of attack and low reynolds number | |
| Czech et al. | Cavity noise generation for circular and rectangular vent holes | |
| EP2337738B1 (en) | Bluff body noise control | |
| Uruba | Flow control using synthetic jet actuators | |
| Viswanath | Some thoughts on separation control strategies | |
| Sharma et al. | Numerical investigations on flow control over blended-wing-body transonic aircraft using synthetic-jet actuators |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20160817 |