Excess thrust control for an aircraft

Patent metadata

Field	Value
Publication number	US-12187443-B2
Application number	US-202117174537-A
Country	US
Kind code	B2
Filing date	Feb 12, 2021
Priority date	Feb 14, 2020
Publication date	Jan 7, 2025
Grant date	Jan 7, 2025

Abstract

Systems and methods for varying excess thrust of an aircraft include: a first electric fan rotatable about a first axis for directing a first air flow along a first air flow path; and a second electric fan rotatable about a second axis different from the first axis for directing a second air flow along a second air flow path fluidly isolated from the first air flow path, wherein the first electric fan and the second electric fan are disposed radially about a roll axis of the aircraft and adjacent an aft end of the aircraft, and the first electric fan and the second electric fan are configured to intake boundary layer air to form the first air flow and the second air flow.

First claim

What is claimed is:

1. A system for varying excess thrust of an aircraft, comprising:
a first electric fan rotatable about a first axis for directing a first air flow along a first air flow path;
a second electric fan rotatable about a second axis different from the first axis for directing a second air flow along a second air flow path fluidly isolated from the first air flow path; and
first and second air intakes in fluid communication with an auxiliary power unit to direct air to the auxiliary power unit,
wherein:
the first electric fan and the second electric fan are disposed radially about a roll axis of the aircraft and adjacent an aft end of the aircraft;
the first electric fan and the second electric fan are disposed in a cavity in a tail cone within the aircraft;
the first electric fan and the second electric fan are configured to intake boundary layer air to form the first air flow and the second air flow; and
the first and second air intakes for the auxiliary power unit are also disposed in the cavity in the tail cone within the aircraft with the first and second electric fans disposed radially about the roll axis of the aircraft.

2. The system of claim 1 , wherein the first electric fan and the second electric fan are coplanar in a single plane that is parallel to a transverse plane containing a pitch axis of the aircraft and a yaw axis of the aircraft.

3. The system of claim 1 , wherein the first electric fan and the second electric fan are bilaterally symmetrical in a plane of symmetry containing the roll axis of the aircraft and a yaw axis of the aircraft.

4. The system of claim 1 , further comprising fairing channels, a first one of the fairing channels surrounding the first electric fan to direct air towards the first air flow path and a second one of the fairing channels surrounding the second electric fan to direct air towards the second air flow path.

5. The system of claim 1 , wherein the first electric fan and the second electric fan are driven by respective electric motors.

6. The system of claim 5 , wherein the electric motors are driven by electric energy from an electric generator of the auxiliary power unit.

7. The system of claim 5 , wherein the electric motors are driven by electric energy supplied by a battery.

8. The system of claim 7 , wherein the electric motors are operable as generators to convert mechanical energy into electric energy to supply to the battery.

9. The system of claim 5 , wherein the electric motors are driven by electric energy from an electric generator of one or more engines of the aircraft.

10. The system of claim 5 , further comprising one or more controllers to control the electric motors.

11. The system of claim 1 , wherein the first electric fan and the second electric fan are ducted fans.

12. The system of claim 1 , wherein the first axis and the second axis are parallel to the roll axis of the aircraft.

13. The system of claim 1 , wherein the first electric fan and the second electric fan are fully disposed within a distance from a surface of the aircraft that is less than a boundary layer thickness formed from the surface of the aircraft during take-off and cruising of the aircraft, the boundary layer thickness being a distance from the surface to a point at which a velocity of a local flow is ninety-nine percent of a velocity of a surrounding freestream flow.

14. The system of claim 1 , further comprising:
a first gate actuable between a closed position, to direct a forward flow of the first air flow in the first air flow path from a forward end of the aircraft to the aft end of the aircraft, and an open position, to direct a reverse flow of the first air flow in the first air flow path from the aft end of the aircraft to the forward end of the aircraft; and
a second gate actuable between a closed position, to direct a forward flow of the second air flow in the second air flow path from a second end of the aircraft to the aft end of the aircraft, and an open position, to direct a reverse flow of the second air flow in the second air flow path from the aft end of the aircraft to the forward end of the aircraft.

15. The system of claim 1 , further comprising:
a third electric fan rotatable about a third axis for directing a third air flow along a third air flow path;
a fourth electric fan rotatable about a fourth axis for directing a fourth air flow along a fourth air flow path;
a fifth electric fan rotatable about a fifth axis for directing a fifth air flow along a fifth air flow path; and
a sixth electric fan rotatable about a sixth axis for directing a sixth air flow along a sixth air flow path,
wherein the third electric fan, the fourth electric fan, the fifth electric fan, and the sixth electric fan are disposed radially about the roll axis of the aircraft and adjacent the aft end of the aircraft and configured to intake boundary layer air to form the third air flow, the fourth air flow, the fifth air flow and the sixth air flow,
each of the first axis, the second axis, the third axis, the fourth axis, the fifth axis, and the sixth axis are different from each other, and
each of the first air flow path, the second air flow path, the third air flow path, the fourth air flow path, the fifth air flow path, and the sixth air flow path are fluidly isolated from each other.

16. An aircraft comprising a first engine, a second engine and the system of claim 1 .

17. The aircraft of claim 16 , wherein the system is configured to generate forward takeoff thrust to supplement thrust generated by the first engine and the second engine during takeoff of the aircraft.

18. The aircraft of claim 16 , wherein the system is configured to generate forward cruise thrust to supplement thrust generated by the first engine and the second engine during cruise of the aircraft.

Assignees

• Bombardier Inc

Inventors

• Asselin Mario

Classifications

• B64C21/01 Primary

  Boundary layer ingestion [BLI] propulsion · CPC title

• B64D27/355

  using fuel cells · CPC title

• B64D27/32

  within, or attached to, fuselages · CPC title

• B64D35/025

  of parallel type · CPC title

• B64D27/33

  Hybrid electric aircraft · CPC title