Center fuel tank assembly with partitioned center fuel tank for an aircraft and methods of sequencing fuel for the same

Patent metadata

Field	Value
Publication number	US-10807702-B2
Application number	US-201815961838-A
Country	US
Kind code	B2
Filing date	Apr 24, 2018
Priority date	Apr 24, 2018
Publication date	Oct 20, 2020
Grant date	Oct 20, 2020

Abstract

There is provided a center fuel tank assembly for an aircraft. The assembly includes a center fuel tank disposed in a central part of the aircraft. The assembly further includes one or more fuel barrier members partitioning the center fuel tank into two or more separate volume sections comprising two or more separate sub-tanks arranged in a fore-to-aft alignment to form a partitioned center fuel tank. The assembly further includes a fuel flow control assembly coupled to each of the two or more separate sub-tanks, each fuel flow control assembly operating independently. A sequential fuel burn of fuel in the two or more separate sub-tanks is made in a fore-to-aft sequence while the aircraft is in flight, to assist in shifting aftward a center of gravity (CG) of the aircraft, to reduce aircraft drag.

First claim

What is claimed is:

1. A center fuel tank assembly for an aircraft, the center fuel tank assembly comprising:
a center fuel tank disposed in a central part of the aircraft;
one or more fuel barrier members partitioning the center fuel tank into two or more separate volume sections comprising two or more separate sub-tanks arranged in a fore-to-aft alignment to form a partitioned center fuel tank, each of the two or more separate sub-tanks defining a closed interior fuel containment region configured to contain fuel for use by the aircraft; and
a fuel flow control assembly coupled to each of the two or more separate sub-tanks, each fuel flow control assembly operating independently, and the fuel flow control assembly configured to control a sequential fuel burn of the fuel in the two or more separate sub-tanks in a fore-to-aft sequence while the aircraft is in flight, to assist in shifting aftward a center of gravity (CG) of the aircraft, to reduce aircraft drag.

2. The center fuel tank assembly of claim 1 , further comprising a fuel pickup element coupled to each of the two or more separate sub-tanks, the fuel pickup element further coupled to a fuel scavenge system for the aircraft, wherein the fuel pickup element is configured to transport any residual fuel from each of the two or more separate sub-tanks to the fuel scavenge system.

3. The center fuel tank assembly of claim 1 , further comprising one or more access openings formed through each of the two or more separate sub-tanks.

4. The center fuel tank assembly of claim 1 , further comprising a fuel quantity indicator coupled to each of the two or more separate sub-tanks, the fuel quantity indicator further coupled to a fuel quantity indication system (FQIS) for the aircraft that calculates a usable fuel quantity in each of the two or more separate sub-tanks.

5. The center fuel tank assembly of claim 1 , further comprising one or more nitrogen generation system (NGS) distribution elements coupled to each of the two or more separate sub-tanks, the one or more NGS distribution elements configured to distribute nitrogen-enriched air (NEA) for a nitrogen generation system (NGS) for the aircraft.

6. The center fuel tank assembly of claim 1 , wherein the one or more fuel barrier members comprise one or more of, a structural wall partition, a rigid divider structure, a span wise beam, a rib, a spar, a stringer, and a panel.

7. The center fuel tank assembly of claim 1 , wherein the one or more fuel barrier members form one or more substantially linear fuel barriers between the two or more separate sub-tanks.

8. The center fuel tank assembly of claim 1 , wherein the one or more fuel barrier members form one or more nonlinear fuel barriers between the two or more separate sub-tanks.

9. The center fuel tank assembly of claim 1 , wherein the center fuel tank has one fuel barrier member, and two separate sub-tanks comprising a forward sub-tank and an aft sub-tank.

10. The center fuel tank assembly of claim 1 , wherein the center fuel tank has two fuel barrier members, and three separate sub-tanks comprising a forward sub-tank, an aft sub-tank, and an intermediate sub-tank.

11. The center fuel tank assembly of claim 1 , further comprising a sealing material applied to each of the one or more fuel barrier members, to seal each of the one or more fuel barrier members, so as to prevent the fuel from passing between the two or more separate sub-tanks.

12. An aircraft comprising:
a fuselage;
a first wing and a second wing, each attached to the fuselage;
a first main fuel tank disposed in the first wing;
a second main fuel tank disposed in the second wing; and
a center fuel tank assembly disposed in a central part of the aircraft, and positioned between the first main fuel tank and the second main fuel tank, the center fuel tank assembly comprising:
a center fuel tank comprising a body with a center section within a central fuselage area of the fuselage, a first portion extending laterally from the center section and positioned within a first wing portion of the first wing, and a second portion extending laterally from the center section opposite the first portion and positioned within a second wing portion of the second wing;
one or more fuel barrier members partitioning the center fuel tank into two or more separate volume sections comprising two or more separate sub-tanks arranged in a fore-to-aft alignment to form a partitioned center fuel tank, each of the two or more separate sub-tanks defining a closed interior fuel containment region configured to contain fuel for use by the aircraft;
a sealing material applied to each of the one or more fuel barrier members, to seal each of the one or more fuel barrier members, so as to prevent the fuel from passing between the two or more separate sub-tanks;
a fuel flow control assembly coupled to each of the two or more separate sub-tanks, each fuel flow control assembly operating independently, and the fuel flow control assembly configured to control a sequential fuel burn of the fuel in the two or more separate sub-tanks in a fore-to-aft sequence while the aircraft is in flight, to assist in shifting aftward a center of gravity (CG) of the aircraft, to reduce aircraft drag;
a fuel pickup element coupled to each of the two or more separate sub-tanks and further coupled to a fuel scavenge system for the aircraft;
one or more access openings formed through each of the two or more separate sub-tanks;
a fuel quantity indicator coupled to each of the two or more separate sub-tanks and further coupled to a fuel quantity indication system (FQIS) for the aircraft that calculates a usable fuel quantity in each of the two or more separate sub-tanks; and
one or more nitrogen generation system (NGS) distribution elements coupled to each of the two or more separate sub-tanks, and configured to distribute nitrogen-enriched air (NEA) for a nitrogen generation system (NGS) for the aircraft.

13. The aircraft of claim 12 , wherein the one or more fuel barrier members comprise one or more of, a structural wall partition, a rigid divider structure, a span wise beam, a rib, a spar, a stringer, and a panel.

14. A method of sequencing loading of fuel in an aircraft, the method comprising the steps of:
assembling a center fuel tank assembly in a central part of the aircraft between a first main fuel tank disposed in a first wing of the aircraft and a second main fuel tank disposed in a second wing of the aircraft, the center fuel tank assembly comprising:
a center fuel tank partitioned with one or more fuel barrier members into two or more separate sub-tanks arranged in a fore-to-aft alignment to form a partitioned center fuel tank, each of the two or more separate sub-tanks defining a closed interior fuel containment region configured to contain fuel for use by the aircraft, and each of the one or more fuel barrier members sealed with a sealing material; and
a fuel flow control assembly coupled to each of the two or more separate sub-tanks, each fuel flow control assembly operating independently;

determining a fuel quantity load of fuel needed for the aircraft prior to a planned flight of the aircraft;
loading a portion of the needed fuel evenly into the first main fuel tank and the second main fuel tank, until both the first main fuel tank and the second main fuel tank are fully loaded; and
loading any remaining needed fuel into each separate sub-tank of the two or more separate sub-tanks of the partitioned center fuel tank, starting with an aft-most unloaded sub-tank, and continuing in an aft-to-fore sequence until any remaining needed fuel is loaded, such that a

Assignees

• Boeing Co

Inventors

• Baron Lennard T
• Schulze Todd W
• Rydell Theodore N
• Purcell Timothy W
• Mulvaney Patrick J

Classifications

• B65D90/44

  by use of inert gas for filling space above liquid or between contents · CPC title

• B64D37/04

  Arrangement thereof in or on aircraft · CPC title

• B64C3/34

  Tanks constructed integrally with wings, e.g. for fuel or water · CPC title

• B60K15/077

  with means modifying or controlling distribution or motion of fuel, e.g. to prevent noise, surge, splash or fuel starvation · CPC title

• B64C17/10 Primary

  Transferring fuel to adjust trim · CPC title