Aircraft having an aft engine

Patent metadata

Field	Value
Publication number	US-10370110-B2
Application number	US-201615271776-A
Country	US
Kind code	B2
Filing date	Sep 21, 2016
Priority date	Sep 21, 2016
Publication date	Aug 6, 2019
Grant date	Aug 6, 2019

Abstract

An aircraft is provided including a fuselage that extends along a longitudinal direction between a forward end and an aft end. A boundary layer ingestion fan is mounted to the fuselage at the aft end and is configured for ingesting boundary layer airflow off the surface of the fuselage. The fuselage defines a profile proximate the boundary layer ingestion fan that is optimized for ingesting a maximum amount of boundary layer air and improving propulsive efficiency of the aircraft. More specifically, the fuselage defines a cross sectional profile upstream of the boundary layer ingestion fan that has more cross sectional area in a top half relative to a bottom half as defined relative to a centerline of the boundary layer ingestion fan.

First claim

What is claimed is:

1. An aircraft defining a longitudinal direction, a vertical direction, and a lateral direction, the aircraft comprising:
a fuselage extending between a forward end and an aft end along the longitudinal direction; and
a boundary layer ingestion fan mounted to the fuselage at the aft end of the fuselage, the boundary layer ingestion fan defining a centerline and comprising a plurality of fan blades rotatable about the centerline and a nacelle surrounding the plurality of fan blades,
wherein the fuselage defines a cross section upstream of the boundary layer ingestion fan, the cross section defining a horizontal reference line extending through the centerline of the boundary layer ingestion fan to define a top half having a top half cross sectional area and a bottom half having a bottom half cross sectional area, wherein the top half cross sectional area of the cross section is greater than the bottom half cross sectional area of the cross section.

2. The aircraft of claim 1 , further comprising:
a stabilizer attached to the fuselage and extending between a leading edge and a trailing edge, and wherein the cross section is defined between the leading edge of the stabilizer and the trailing edge of the stabilizer.

3. The aircraft of claim 2 , wherein the cross section is defined at a halfway point between the leading edge of the stabilizer and the trailing edge of the stabilizer.

4. The aircraft of claim 2 , wherein the stabilizer is a vertical stabilizer.

5. The aircraft of claim 1 , wherein the cross section of the fuselage defines a circumference, wherein the fuselage defines a reference circle at the cross section of the fuselage, wherein the reference circle defines a centerpoint at the centerline of the boundary layer ingestion fan, wherein at least a portion of the circumference of the top half of the cross section of the fuselage is located outside the reference circle, and wherein at least a portion of the circumference of the bottom half of the cross section of the fuselage is located inside the reference circle.

6. The aircraft of claim 5 , wherein a circumference of the reference circle is substantially the same as the circumference of the cross section.

7. The aircraft of claim 1 , wherein a maximum displacement of the top half of the cross section relative to the reference circle is equivalent to a maximum displacement of the bottom half of the cross section relative to the reference circle.

8. The aircraft of claim 7 , wherein the maximum displacement of the top half of the cross section relative to the reference circle and the maximum displacement of the bottom half of the cross section relative to the reference circle are positioned at approximately 45 degrees and 135 degrees from the vertical direction, respectively.

9. The aircraft of claim 1 , wherein a top surface of the fuselage defines a tangent line at the cross section, the tangent line intersecting a forward lip of the nacelle.

10. The aircraft of claim 2 , wherein a top surface of the fuselage defines:
a first point located in a plane perpendicular to the longitudinal direction, wherein the first point is positioned at or aft of where the leading edge of the stabilizer meets the fuselage;
a second point located in a plane perpendicular to the longitudinal direction and positioned at or forward of where the trailing edge of the stabilizer meets the fuselage;
an upper midpoint;
a first portion of the top surface, the first portion extending between the first point and the upper midpoint, the first portion being convex and having a first radius of curvature; and
a second portion of the top surface, the second portion extending between the upper midpoint and the second point, the second portion being convex and having a second radius of curvature, the second radius of curvature being smaller than the first radius of curvature.

11. The aircraft of claim 10 , wherein the upper midpoint is located on the top surface of the fuselage approximately at a halfway point between the leading edge of the stabilizer and the trailing edge of the stabilizer.

12. The aircraft of claim 2 , wherein a bottom surface of the fuselage defines:
a first point located in a plane perpendicular to the longitudinal direction, wherein the first point is positioned at or aft of where the leading edge of the stabilizer meets the fuselage;
a second point located in a plane perpendicular to the longitudinal direction and positioned at or forward of where the trailing edge of the stabilizer meets the fuselage:
a lower midpoint;
a first portion of the bottom surface, the first portion extending between the first point and the lower midpoint, the first portion being convex and having a first radius of curvature; and
a second portion of the bottom surface, the second portion extending between the lower midpoint and the second point, the second portion being convex and having a second radius of curvature, the second radius of curvature being smaller than the first radius of curvature.

13. The aircraft of claim 12 , wherein the lower midpoint is located on the bottom surface of the fuselage approximately at a halfway point between the leading edge of the stabilizer and the trailing edge of the stabilizer.

14. An aircraft defining a longitudinal direction, a vertical direction, and a lateral direction, the aircraft comprising:
a fuselage extending between a forward end and an aft end along the longitudinal direction, the fuselage defining a top surface and a bottom surface; and
a boundary layer ingestion fan mounted to the fuselage at the aft end of the fuselage, the boundary layer ingestion fan defining a centerline and comprising a plurality of fan blades rotatable about the centerline and a nacelle surrounding the plurality of fan blades,
wherein the fuselage defines a cross section upstream of the boundary layer ingestion fan, the cross section defining a circumference and a horizontal reference line, wherein the horizontal reference line extends across a widest portion of the cross section along the lateral direction, the fuselage further defining a reference circle at the cross section and having the horizontal reference line as a diameter of the reference circle, wherein at least a portion of the circumference at a top half of the cross section of the fuselage is located outside the reference circle, and wherein at least a portion of the circumference at a bottom half of the cross section of the fuselage is located inside the reference circle.

15. The aircraft of claim 14 , further comprising:
a stabilizer attached to the fuselage and extending between a leading edge and a trailing edge, and wherein the cross section is defined between the leading edge of the stabilizer and the trailing edge of the stabilizer.

16. The aircraft of claim 14 , wherein a circumference of the reference circle is substantially the same as the circumference of the cross section.

17. The aircraft of claim 14 , wherein a top surface of the fuselage defines a tangent line at the cross section, the tangent line intersecting a forward lip of the nacelle.

Assignees

• Gen Electric

Inventors

• Ramakrishnan Kishore
• Yao Jixian
• Pastouchenko Nikolai N
• Malcevic Ivan

Classifications

• B64D27/20

  within, or attached to, fuselages · CPC title

• B64C2001/0045

  Fuselages characterised by special shapes · CPC title

• B64C1/16

  specially adapted for mounting power plant · CPC title

• B64D27/14 Primary

  within, or attached to, fuselages · CPC title

• B64C2230/04

  by actively generating fluid flow · CPC title