Aircraft fuel system

Patent metadata

Field	Value
Publication number	US-10654581-B2
Application number	US-201615342514-A
Country	US
Kind code	B2
Filing date	Nov 3, 2016
Priority date	Nov 5, 2015
Publication date	May 19, 2020
Grant date	May 19, 2020

Abstract

An aircraft fuel system having a fuel tank and a baffle dividing the fuel tank into a primary fuel containing space and a secondary fuel containing space. A fuel drain is provided through which fuel flows from the primary fuel containing space into the secondary fuel containing space. A primary fuel outlet draws fuel from the primary fuel containing space and a secondary fuel outlet draws fuel from the secondary fuel containing space, wherein fuel flow through the primary fuel outlet causes fuel flow through the secondary fuel outlet. The mass flow rate of fuel through the fuel drain is restricted so that the allowable mass flow rate of fuel through the secondary fuel outlet is configured to be greater than the allowable mass flow rate of fuel through the fuel drain in the baffle.

First claim

The invention claimed is:

1. An aircraft fuel system comprising:
a fuel tank configured to contain liquid fuel, wherein the fuel tank includes walls defining a fuel containing chamber;
a baffle dividing the fuel containing chamber into a primary fuel containing space and a secondary fuel containing space,
a fuel drain through which the liquid fuel flows from the primary fuel containing space into the secondary fuel containing space, wherein the fuel drain is configured to allow fuel to drain into the secondary fuel containing space from the primary fuel containing space at a rate no greater than a maximum mass flow drain rate;
a primary fuel outlet configured to draw the liquid fuel from the primary fuel containing space, and
a secondary fuel outlet configured to draw the liquid fuel from the secondary fuel containing space, wherein the secondary fuel outlet is configured to draw the liquid fuel at an allowable mass flow rate of the liquid fuel greater than the maximum mass flow drain rate;
wherein the secondary fuel outlet is configured so that the liquid fuel flow through the primary fuel outlet causes the liquid fuel flow to be drawn through the secondary fuel outlet, and
an auxiliary duct connects the secondary fuel outlet with the primary fuel outlet so that the secondary fuel outlet receives pressurized fuel from the primary fuel outlet.

2. The aircraft fuel system according to claim 1 , wherein the primary fuel outlet comprises a fuel pump in fluid communication with the primary fuel outlet.

3. The aircraft fuel system according to claim 2 , wherein the primary fuel outlet comprises a fuel drawing end in fluid communication with the primary fuel containing space.

4. The aircraft fuel system according to claim 3 , wherein the baffle extends proximate to the fuel drawing end of the primary fuel outlet.

5. The aircraft fuel system according to claim 3 , wherein the fuel pump is at the fuel drawing end of the primary fuel outlet.

6. The aircraft fuel system according to claim 1 , further comprising an injector configured to draw fuel through the secondary fuel outlet in response to fuel drawn through the primary fuel outlet.

7. The aircraft fuel system according to claim 6 , wherein the injector is configured to feed fuel passing through the injector to the primary fuel containing space.

8. The aircraft fuel system according to claim 1 , wherein at least part of the secondary fuel containing space is below the primary fuel containing space.

9. The aircraft fuel system according to claim 1 , wherein at least part of the secondary fuel outlet is below the primary fuel outlet.

10. The aircraft fuel system according to claim 9 , wherein the fuel drain is in the baffle.

11. The aircraft fuel system according to claim 10 , wherein the baffle comprises a diaphragm and the fuel drain is in the diaphragm.

12. The aircraft fuel system according to claim 10 , wherein at least part of the baffle is porous, and the fuel drain is formed by the at least part of the baffle that is porous.

13. The aircraft fuel system according to claim 1 , wherein the fuel drain is at least one orifice.

14. The aircraft fuel system according to claim 13 , wherein the baffle comprises a structural component of the aircraft and the fuel drain is in the structural component.

15. The aircraft fuel system according to claim 1 , further comprising a vent, the vent communicating with the secondary fuel containing space.

16. The aircraft fuel system according to claim 15 , wherein the vent is configured to allow the flow of fuel from the primary fuel containing space into the secondary fuel containing space in a first condition, and the vent is restricted from allowing the flow of fuel from the primary fuel containing space into the secondary fuel containing space in a second condition.

17. An aircraft wing comprising the aircraft fuel system according to claim 1 .

18. An aircraft comprising the aircraft fuel system according to claim 1 .

19. The aircraft fuel system of claim 1 , wherein the baffle and the walls entirely separate the secondary fuel containing space from the primary fuel containing space.

20. The aircraft fuel system of claim 1 wherein the fuel drain is at or below an elevation of a fuel pump in the primary fuel containing space.

21. The aircraft fuel system of claim 20 , including a vent having an inlet open to the primary fuel containing space and an outlet open to the secondary fuel containing space, wherein the opening is above the elevation of the fuel pump.

22. The aircraft fuel system of claim 1 , wherein the secondary fuel outlet includes an inlet in a region of the secondary fuel containing space below a lowermost region of the primary fuel containing space.

23. A method of drawing fuel from an aircraft fuel tank of an aircraft fuel system, the fuel tank having a primary fuel containing space, a secondary fuel containing space, a baffle dividing the fuel tank into the primary fuel containing space and the secondary fuel containing space, the method comprising:
drawing fuel from the primary fuel containing space through a primary fuel outlet,
drawing fuel from the secondary fuel containing space through a secondary fuel outlet,
draining fuel from the primary fuel containing space into the secondary fuel containing space, wherein the draining of the fuel is through a drain between the secondary fuel containing space and the primary fuel containing space, and the drain is configured to permit fuel flowing at most at a maximum mass flow drain rate, and
supplying pressurized fuel from the primary fuel outlet to the secondary fuel outlet to cause fuel flow through the secondary fuel outlet,
wherein the maximum mass flow drain rate of fuel is less than an allowable mass flow rate of fuel drawn from the secondary fuel containing space through the secondary fuel outlet.

24. The method of claim 23 , wherein the baffle and the walls entirely separate the secondary fuel containing space from the primary fuel containing space.

25. The method of claim 24 , wherein the secondary fuel outlet includes an inlet in a region of the secondary fuel containing space below a lowermost region of the primary fuel containing space.

26. The method of claim 23 , wherein the drain is at or below an elevation of a fuel pump in the primary fuel containing space.

27. The method of claim 26 , further comprising venting fuel between the primary fuel containing space and the secondary fuel containing space through a vent in an upper elevation of the primary fuel containing chamber, wherein the vent has an opening in the primary fuel containing space which is above the elevation of the fuel pump.

Assignees

• Airbus Operations Ltd

Inventors

• Morgan Angus
• Slack Christopher

Classifications

• B64D37/22

  facilitating emptying in any position of tank · CPC title

• B64D37/20

  Emptying systems · CPC title

• B64D37/08 Primary

  Internal partitioning · CPC title

• B64D37/04

  Arrangement thereof in or on aircraft · CPC title

• B64D37/14

  Filling or emptying (transferring fuels to adjust aircraft trim B64C17/10) · CPC title