AERO-ACOUSTIC OPTIMISATION METHOD FOR COMPLEX-SECTION MECHANICAL PARTS AND CORRESPONDING MECHANICAL PART AND LANDING GEAR

• US 20110309193A1
• Filed: 06/20/2011
• Published: 12/22/2011
• Est. Priority Date: 06/21/2010
• Status: Active Grant

• Current Assignee: Airbus Operations (European Aeronautic Defence and Space Company EADS NV)
• Original Assignee: Airbus Operations (European Aeronautic Defence and Space Company EADS NV)
• Inventors: Seror Goguet, Christelle
• Granted Patent: US 8,668,164 B2
• Time in Patent Office: Days
• US Class Current: 244/100.R
• CPC Class Codes: B64C 2025/003 Means for reducing landing gear noise, or turbulent flow around it, e.g. landing gear doors used as deflectors
• CPC Class Codes: B64C 25/001 Devices not provided for in the groups B64C25/02 - B64C25/68
• CPC Class Codes: B64C 25/16 Fairings movable in conjunction with undercarriage elements
• CPC Class Codes: B64C 7/00 Structures or fairings not otherwise provided for
• CPC Class Codes: Y10T 29/49 Method of mechanical manufacture
• CPC Class Codes: Y10T 428/12361 having aperture or cut
• CPC Class Codes: Y10T 428/12375 having member which crosses the plane of another member [e.g., T or X cross section, etc.]

Abstract

The invention is intended to reduce the drag caused by a complex-section part in an airflow, for example the landing gear of an aircraft, making it possible to optimise the lift/drag ratio and to reduce the aerodynamic noise by reducing the local noise source combined with a global optimisation of the aeroplane related to the reduction in drag. To do so, the invention provides for the shaping of the complex part, masking its form with a special casing.

According to one embodiment, the aero-acoustically optimised complex-section metal mechanical part is fitted with an aerodynamically shaped cover made of several longitudinal parts articulated with hinges to facilitate their installation. This cover is attached to at least two supports placed away from one another along the axis of the part, each support is bolted to the cover and mates with the section of the part. The external face of the cover is cylindrical and its internal face bears against the supports. The cover advantageously has a translucent part beside the walls of a remaining opaque part. Stops are provided on the part to limit the translational movement of the cover.

Claims

1. Aero-acoustic optimisation method for a complex-section mechanical part having a longitudinal axis that can be placed in an airflow, this method comprising aerodynamically enveloping the mechanical part, using means not attached to the part but that mate locally with it.

2. Optimisation method according to claim 1, wherein the part is left partially visible to facilitate inspection of the part.

3. Optimisation method according to claim 1, wherein passive noise absorption is provided by partially enveloping it with a mesh.

4. Optimisation method according to claim 1, wherein the part is enveloped by a variable-curvature aerodynamic shape.

5. Complex-section mechanical metal part along an axis that is aero-acoustically optimised according to the method according to claim 1, wherein an aerodynamic envelope is attached to means comprising at least two supports arranged away from one another along the axis of the part, each support having an external contour and an internal contour at least partially applied to the section of the part, and wherein said envelope comprises a cover having an external cylindrical face and an internal face that presses against the external contours of the supports to which the cover is attached using fixing means.

6. Mechanical part according to claim 5, wherein stops are formed on the part and placed on either side of at least one support to stop the cover from moving.

7. Mechanical part according claim 5, wherein each support comprises a plate of constant thickness and an internal contour that at least partially mates with the shape of the part.

8. Mechanical part according to the above claim, wherein each support comprises at least two parts connected to each other.

9. Mechanical part according to claim 5, wherein the external face of the cover has an aerodynamic shape of circular, elliptical, oblong, oval or droplet section that is at least partially cylindrical.

10. Mechanical part according to claim 5, wherein the cover and/or the supports are made of composite or plastic material whose density is significantly lower than that of the metal part.

11. Mechanical part according to claim 5, wherein the cover comprises one or more parts, including a longitudinal hinge between the two parts that can open along the length of the part.

12. Mechanical part according to the above claim, wherein the cover partially covers the part lengthways with locally made apertures.

13. Mechanical part according to claim 11, wherein the cover has a longitudinal part made of plastic or composite translucent material.

14. Mechanical part according to claim 11, wherein the cover has a longitudinal part made of material providing passive noise absorption, which may be a mesh with an appropriate opening size, a bristle surface of suitable density or a sharkskin coating.

15. Landing gear of an aircraft comprising at least one “

H”

shaped complex-section mechanical part according to claim 5 used as a strut in the landing gear.