Search

EP-4242112-B1 - FAIRING FOR WING-MOUNTED ENGINES

EP4242112B1EP 4242112 B1EP4242112 B1EP 4242112B1EP-4242112-B1

Inventors

  • HOWE, SEAN P.
  • Hoisington, Zachary C.

Dates

Publication Date
20260513
Application Date
20230307

Claims (15)

  1. An aircraft (100) defining a longitudinal centerline axis (AL) and comprising: a wing (120) having a leading edge (122), a trailing edge (124) aft of the leading edge (122), a wing thickness (TW), and a wing chord (126); an engine (110) defining a longitudinal axis (AL) vertically aligned with the wing chord (126) and parallel with the longitudinal centerline axis (A) of the aircraft (100); a pylon (140) connecting the wing (120) to the engine (110); a fairing (130) positioned over the pylon (140), the fairing (130) defining a horizontal plane (PH), a first plane (P1) settable perpendicular to the longitudinal axis (AL), and a second plane (P2) settable perpendicular to the longitudinal axis (AL), the second plane (P2) being aft of the first plane (P1) with respect to a direction from the leading edge (122) to the trailing edge (124) of the wing (120), a reference line (LR) being defined on the horizontal plane (PH) as a projection of the longitudinal axis (AL), wherein the fairing (130) comprises: a fairing body (136) defining an aerodynamic surface (136'), the aerodynamic surface (136') comprising an outboard portion (132) and an inboard portion (134), the inboard portion (134) being configured such that: the first plane (P1) intersects the horizontal plane (PH) and the aerodynamic surface (136') of the inboard portion (134) at a first intersection point (I1), the first intersection point (I1) is laterally displaced from the reference line (LR) by a first distance (D1), the second plane (P2) intersects the horizontal plane (PH) and the aerodynamic surface (136') of the inboard portion (134) at a second intersection point (I2), the second intersection point (I2) is laterally displaced from the reference line (LR) by a second distance (D2), the second distance (D2) is greater than the first distance (D1), wherein the first intersection point (I1) and the second intersection point (I2) define a line (S), and wherein the line (S) intersects the reference line (LR) at an angle (θ) of about 1 degree to about 10 degrees, wherein a reference segment (C) is defined on the horizontal plane (PH) as a projection of the wing cord (126), the reference segment (C) having a leading end (CL), an aft end (CA), and a length (CW) from the leading end (CL) to the aft end (CA), and wherein the first plane (P1) intersects the reference segment (C) at a point located approximately 5% to approximately 15% along the length (CW) of the reference segment (C), and wherein the second plane (P2) intersects the reference segment (C) at a point located approximately 20% to approximately 40% along the length (CW) of the reference segment (C).
  2. The aircraft (100) of Claim 1, wherein the inboard portion (134) of the aerodynamic surface (136') has a different geometry than the outboard portion (132) of the aerodynamic surface (136').
  3. The aircraft (100) of Claim 1, wherein the angle (θ) is about 2 degrees to about 7 degrees.
  4. The aircraft (100) of any one of Claims 1-3, wherein the angle (θ) is about 3 degrees to about 6 degrees.
  5. The aircraft (100) of any one of Claims 1-4, wherein the first plane (P 1 ) intersects the reference segment (C) at a point located approximately 10% along the length (C W ) of the reference segment (C).
  6. The aircraft (100) of any one of Claims 1-5, wherein the second plane (P 2 ) intersects the reference segment (C) at a point located approximately 30% along the length (C W ) of the reference segment (C).
  7. The aircraft (100) of any one of Claims 1-6, wherein the horizontal plane (P H ) is vertically displaced along a vertical axis (A V ) from a wing surface lowest point (128) by a distance of at least 0.5 times the wing thickness (T W ) when the fairing (130) is received over a pylon (140), the vertical axis (A V ) being perpendicular to the horizontal plane (P H ).
  8. The aircraft (100) of any one of Claims 1-7, wherein the horizontal plane (P H ) is vertically displaced along a vertical axis (A V ) from a wing surface lowest point (128) by a distance of at least 1 times the wing thickness (T W ) when the fairing (130) is received over a pylon (140), the vertical axis (A V ) being perpendicular to the horizontal plane (P H ).
  9. The aircraft (100) of any one of Claims 1-8, wherein the horizontal plane (P H ) is vertically displaced along a vertical axis (A V ) from a wing surface lowest point (128) by a distance of at least 1.5 times the wing thickness (T W ) when the fairing (130) is received over a pylon (140), the vertical axis (A V ) being perpendicular to the horizontal plane (P H ).
  10. The aircraft (100) of any one of Claims 1-9, wherein the horizontal plane (P H ) is vertically displaced along a vertical axis (A V ) from a wing surface lowest point (128) by a distance of at least 2 times the wing thickness (T W ) when the fairing (130) is received over a pylon (140), the vertical axis (A V ) being perpendicular to the horizontal plane (P H ).
  11. The aircraft (100) of any one of Claims 1-10, wherein the outboard portion (132) is configured such that: the first plane (P 1 ) intersects the horizontal plane (P H ) and the aerodynamic surface (136') of the outboard portion (132) at a third intersection point (I 3 ), the third intersection point (I 3 ) is laterally displaced from the reference line (L R ) by a third distance (D 3 ), the second plane (P 2 ) intersects the horizontal plane (P H ) and the aerodynamic surface (136') of the outboard portion (132) at a fourth intersection point (I 4 ), the fourth intersection point (I 4 ) is laterally displaced from the reference line (L R ) by a fourth distance (D 4 ), and the third distance (D 3 ) is greater than the fourth distance (D 4 ).
  12. The aircraft according to Claim 1, wherein the engine (110) further defines a center axis (A C ), and preferably: the center axis (A C ) is aligned with the longitudinal axis (A L ); or the center axis (A C ) is offset from the longitudinal axis (A L ) by between about 1 degree to about 10 degrees.
  13. A method (200) for reducing drag on an aircraft (100) defining a longitudinal centerline axis (A), the aircraft (100) comprising a wing (120) having a leading edge (122), a trailing edge (124) aft of the leading edge (122), a wing thickness (TW), and a wing chord (126), an engine (110) having a longitudinal axis (AL) vertically aligned with the wing chord (126) and parallel to the longitudinal centerline axis (A) of the aircraft (100), a pylon (140) connecting the wing (120) to the engine (110), the method (200) comprising positioning a fairing (130) over the pylon (140), the fairing (130) defining a horizontal plane (PH), a first plane (P 1 ) settable perpendicular to the longitudinal axis (AL), and a second plane (P2) settable perpendicular to the longitudinal axis (AL), the second plane (P2) being aft of the first plane (P1) with respect to a direction from the leading edge (122) to the trailing edge (124) of the wing (120), a reference line (LR) being defined on the horizontal plane (PH) as a projection of the longitudinal axis (AL), and the fairing (130) comprising: a fairing body (136) defining an aerodynamic surface (136'), the aerodynamic surface (136') comprising an outboard portion (132) and an inboard portion (134), the inboard portion (134) being configured such that: the first plane (P1) intersects the horizontal plane (PH) and the aerodynamic surface (136') of the inboard portion (134) at a first intersection point (I1), the first intersection point (I1) is laterally displaced from the reference line (LR) by a first distance (D1), the second plane (P2) intersects the horizontal plane (PH) and the aerodynamic surface (136') of the inboard portion (134) at a second intersection point (I2), the second intersection point (I2) is laterally displaced from the reference line (LR) by a second distance (D2), the second distance (D2) is greater than the first distance (D1), wherein the first intersection point (I1) and the second intersection point (I2) define a line (S), and wherein the line (S) intersects the reference line (LR) at an angle (θ) of about 1 degree to about 10 degrees, wherein a reference segment (C) is defined on the horizontal plane (PH) as a projection of the wing cord (126), the reference segment (C) having a leading end (CL), an aft end (CA), and a length (CW) from the leading end (CL) to the aft end (CA), and wherein the first plane (P1) intersects the reference segment (C) at a point located approximately 5% to approximately 15% along the length (CW) of the reference segment (C), and wherein the second plane (P2) intersects the reference segment (C) at a point located approximately 20% to approximately 40% along the length (CW) of the reference segment (C).
  14. The method (200) of Claim 13, wherein the inboard portion (134) of the aerodynamic surface (136') has a different geometry than the outboard portion (132) of the aerodynamic surface (136').
  15. The method (200) of Claim 13 or 14, wherein the angle (θ) is about 2 degrees to about 7 degrees, preferably about 3 degrees to about 6 degrees.

Description

FIELD The present disclosure is generally related to aerospace structures and, more particularly, to fairings and methods for reducing drag on an aircraft. BACKGROUND Aircraft having wing-mounted engines typically utilize support structures, such as pylons, to support engines relative to the wings. Many aircraft experience high amount of interference, such as drag, around the engine and pylon juncture, thus risking damage and detrimental effects to the aircraft. Current solutions for reducing drag and interference include moving the engine location, slowing the travel speed of the aircraft, or changing geometry of the wing. These solutions are not ideal because they may increase weight, increase time to complete a flight, and changing the wing shape may not be possible for different airplane configurations. Document US 2009/032639 A1, in accordance with its abstract, states an aircraft wing arrangement including a wing and at least one strut for attaching the aircraft engine suspended under the wing and including a front zone situated projecting towards the front with respect to a leading edge of the wing. The front zone includes a lateral projection delimiting a lateral air flow channel while being projected towards a proximal end of the wing. Document FR 2898336A1, in accordance with its abstract, states a fairing having lateral flanges spaced along a transversal direction, where the flanges are arranged on both sides of a vertical plane passing through a longitudinal axis. A waist is arranged along the direction and is formed on the flanges using respective reinforcements, where the reinforcements are situated opposite to each other. The reinforcements are not forcibly symmetrical with respect to a plane passing through the axis. Document XP 001247865 "Reduction of drag rise on Convair 990 Airplane" by Kutney J et Al., in accordance with its abstract, states modifications to Convair 990 airplane for delaying the drag rise, said modifications including a forward pylon fairing, an aft pylon fairing, and four terminal fairings added to the inboard sides of the nacelles. Document US 2008/001036 A1, in accordance with its abstract, states an aerospace vehicle fairing systems and associated methods, including fairings that house flap surface drive mechanisms on aircraft. The method includes adjusting lift distribution across an airfoil. The airfoil includes a first inboard portion and a second outboard portion. The method can include locating a point of maximum curvature of a first fairing approximately forward of a trailing edge of the airfoil proximate to the first inboard portion. The method can also include locating a point of maximum curvature of a second fairing approximately aft of a trailing edge of the airfoil proximate to the second outboard portion. The locations of the points of maximum curvature for the first and second fairings are based on a target lift distribution. In view of the foregoing, those skilled in the art continue with research and development efforts in the field of improving structures and methods for reducing drag on aircraft. SUMMARY In a first aspect, an aircraft according to claim 1 is provided. In a second aspect, a method for reducing drag on an aircraft according to claim 13 is provided. Preferred embodiments are provided in the dependent claims. Other examples of the disclosed fairings and methods will become apparent from the following detailed description, the accompanying drawings, and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic top cross-sectional view of a portion of an aircraft;FIG. 2 is a schematic side perspective view of the portion of the aircraft of FIG. 1;FIG. 3 is a schematic view of a plane with projected intersection points of the portion of the aircraft of FIG. 1;FIG. 4 is a schematic cross-sectional view of a portion of a wing of the portion of the aircraft of FIG. 1;FIG. 5 is a flow diagram of a method for reducing drag on an aircraft;FIG. 6 is a flow diagram of an aircraft manufacturing and service methodology; andFIG. 7 is a schematic block diagram of an example of an aircraft. DETAILED DESCRIPTION The following detailed description refers to the accompanying drawings, which illustrate specific examples described by the present disclosure. Like reference numerals may refer to the same feature, element, or component in the different drawings. Illustrative, non-exhaustive examples, which may be, but are not necessarily, claimed, of the subject matter according to the present disclosure are provided below. Reference herein to "example" means that one or more feature, structure, element, component, characteristic, and/or operational step described in connection with the example is included in at least one aspect, embodiment, and/or implementation of the subject matter according to the present disclosure. Thus, the phrases "an example," "another example," "one or more examples," and similar language throughout the present disc