Aircraft having an aft engine

Patent metadata

Field	Value
Publication number	US-11299283-B2
Application number	US-201916512730-A
Country	US
Kind code	B2
Filing date	Jul 16, 2019
Priority date	Sep 21, 2016
Publication date	Apr 12, 2022
Grant date	Apr 12, 2022

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, the fuselage defining a surface;
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; and
a stabilizer attached to the fuselage and extending between a leading edge and a trailing edge,
wherein the surface of the fuselage defines:
a first point located in a plane perpendicular to the longitudinal direction and positioned where the leading edge of the stabilizer meets the fuselage;
a second point located in a plane perpendicular to the longitudinal direction and positioned where the trailing edge of the stabilizer meets the fuselage;
an inflection point;
a first portion of the surface, the first portion extending between the first point and the inflection point, the first portion being convex; and
a second portion of the surface, the second portion extending between the inflection point and the second point, the second portion being concave.

2. The aircraft of claim 1 , wherein the surface of the fuselage is a bottom surface of the fuselage.

3. The aircraft of claim 1 , wherein the surface of the fuselage is a top surface of the fuselage.

4. The aircraft of claim 1 , wherein the stabilizer is a vertical stabilizer.

5. The aircraft of claim 1 , wherein the inflection point is defined at a halfway point between the leading edge of the stabilizer and the trailing edge of the stabilizer.

6. The aircraft of claim 1 , wherein the inflection point is positioned upstream of an inlet of the boundary layer ingestion fan.

7. The aircraft of claim 1 , wherein the first portion defines a first radius of curvature and the second portion defines a second radius of curvature, the second radius of curvature being smaller than the first radius of curvature.

8. The aircraft of claim 1 , wherein the first portion defines a first radius of curvature and the second portion defines a second radius of curvature, the second radius of curvature being substantially the same as the first radius of curvature.

9. The aircraft of claim 1 , wherein a tangent line extends parallel to the surface of the fuselage and intersects a forward lip of the boundary layer ingestion fan, wherein the tangent line is parallel to the fuselage approximately halfway between the leading edge and the trailing edge of the stabilizer.

10. 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 surface;
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; and
a stabilizer attached to the fuselage and extending along a junction line between a leading edge and a trailing edge,
wherein the surface of the fuselage defines:
a first region extending between the leading edge of the stabilizer and first point along the junction line, the first region having a first radius of curvature;
a second region extending between the first point and a second point along the junction line, the second region having a second radius of curvature; and
a third region extending between the second point and a third point along the junction line, the third region having a third radius of curvature.

11. The aircraft of claim 10 , wherein the first region and the second region are convex, and the third region is concave.

12. The aircraft of claim 10 , wherein the first region defines an average angle along a length of the first region relative to the longitudinal direction, the average angle being less than 10 degrees.

13. The aircraft of claim 10 , wherein the first radius of curvature is larger than the second radius of curvature.

14. The aircraft of claim 10 , wherein a ratio of the first radius of curvature to the second radius of curvature is greater than 2:1.

15. The aircraft of claim 14 , wherein the ratio is greater than 4:1.

16. The aircraft of claim 10 , wherein the second region defines an average angle along a length of the second region relative to the longitudinal direction, the average angle being less than 20 degrees.

17. The aircraft of claim 10 , wherein the third radius of curvature is substantially the same as the first radius of curvature.

18. The aircraft of claim 10 , wherein the third point is defined along the junction line at a location upstream of the plurality of fan blades of the boundary layer ingestion fan.

19. The aircraft of claim 10 , wherein the third point is at the trailing edge of the stabilizer.

Assignees

• Gen Electric

Inventors

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

Classifications

• Y02T50/10

  Drag reduction · CPC title

• B64C2001/0045

  Fuselages characterised by special shapes · CPC title

• B64C2230/04

  by actively generating fluid flow · CPC title

• B64D27/20

  within, or attached to, fuselages · CPC title

• B64C5/06

  Fins (B64C5/08 takes precedence) · CPC title