High-aspect ratio hybrid airship

• US 20050269441A1
• Filed: 05/24/2004
• Published: 12/08/2005
• Est. Priority Date: 05/24/2004
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Cassidy, Patrick F., Barocela, Edward
• Granted Patent: US 7,137,592 B2
• Time in Patent Office: Days
• US Class Current: 244/25
• CPC Class Codes: B64B 1/06 Rigid airships; Semi-rigid airships B64B1/58 takes precedence
• CPC Class Codes: B64B 1/24 Arrangement of propulsion plant B64B1/34 takes precedence
• CPC Class Codes: B64B 2201/00 Hybrid airships, i.e. airships where lift is generated aerodynamically and statically
• CPC Class Codes: B64D 2211/00 Arrangements of solar panels on aircraft
• CPC Class Codes: B64D 27/353 using solar cells
• CPC Class Codes: Y02T 50/50 On board measures aiming to increase energy efficiency

Abstract

In one aspect, a hybrid airship including an outer shell, a plurality of helium filled gas envelopes, and an all-electric propulsion system can have a high-aspect ratio wing shape. In some embodiments, the hybrid airship may be launched using buoyancy lift alone and aerodynamic lift may be provided by the all-electric propulsion system. In one aspect, a photovoltaic array and a high energy density power storage system may be combined to power the propulsion system making the propulsion system regenerative. The high-aspect ratio wing shape provides low drag, and can allow the hybrid airship to fly at an altitude of at least about 100,000 ft. By continuously recharging the power storage system, the hybrid airship in accordance with some embodiments can stay aloft for months or even years. The hybrid airship may function as a military intelligence, surveillance, and reconnaissance and communications relay platform.

Claims

1. A high-aspect ratio hybrid airship, comprising:

an outer shell;

a plurality of gas envelopes within said outer shell, wherein said gas envelopes store helium and provide buoyancy lift to said hybrid airship; and

an all-electric propulsion system connected with said outer shell, wherein said all-electric propulsion system is operable to provide aerodynamic lift to said hybrid airship.

2. The high-aspect ratio hybrid airship of claim 1, wherein said outer shell is made out of a semi-rigid material, is inflatable to a wing shape having a high-aspect ratio, and defines an internal volume when inflated.

3. The high-aspect ratio hybrid airship of claim 1, wherein said outer shell is made out of a rigid material having a high-aspect ratio wing shape and defining an internal volume.

4. The high-aspect ratio hybrid airship of claim 1, wherein said outer shell includes an upper skin, a lower skin, a rounded leading edge, and a sharp trailing edge.

5. The high-aspect ratio hybrid airship of claim 4, further comprising a plurality of vertical tails located along said trailing edge.

6. The high-aspect ratio hybrid airship of claim 4, wherein said all-electric propulsion system includes a plurality of propulsion pods located along said trailing edge, a high energy density power storage system located within said internal volume, a photovoltaic array located on said upper skin, and a power conditioning unit located within said internal volume.

7. The high-aspect ratio hybrid airship of claim 6, wherein each of said propulsion pods includes an electric motor and a propeller.

8. The high-aspect ratio hybrid airship of claim 7, wherein said propeller comprises a low Reynolds number propeller.

9. The high-aspect ratio hybrid airship of claim 1, wherein said gas envelopes comprise conformal gas envelopes.

10. The high-aspect ratio hybrid airship of claim 1, wherein said gas envelopes comprise cylindrical gas envelopes.

11. The high-aspect ratio hybrid airship of claim 1, further comprising reservoir gas envelopes, wherein said reservoir gas envelopes receive excess helium during ascent of said hybrid airship.

12. An all-electric propulsion system, comprising:

a high energy density power storage system including a lightweight energy storage medium, wherein said energy storage medium has a high energy density;

an electric motor that receives power from said power storage system during nighttime hours;

a low Reynolds number propeller that is coupled and configured to be driven by said electric motor;

a photovoltaic array, wherein said photovoltaic array is configured to provide power to said electric motor during daylight hours, and to recharge said power storage system; and

a power conditioning unit that distributes electrical power between said photovoltaic array, said energy storage system, and said electric motor.

13. The all-electric propulsion system of claim 12, wherein said energy storage medium comprises a lithium-ion battery.

14. The all-electric propulsion system of claim 12, wherein said energy storage medium comprises a lithium-ion battery system that includes polymer sheets.

15. The all-electric propulsion system of claim 12, wherein said energy storage medium comprises a capacitor bank.

16. The all-electric propulsion system of claim 12, also including a propulsion pod that houses said electric motor and said propeller.

17. The all-electric propulsion system of claim 12, wherein said power conditioning unit further controls the charge/discharge cycle of said power storage system.

18. The all-electric propulsion system of claim 12, wherein said power storage system, said electric motor, said propeller, said photovoltaic array, and said power conditioning unit provide propulsion to a high-aspect ratio hybrid airship.

19. An airfoil for a hybrid airship, said airfoil comprising:

an outer shell having a high-aspect ratio wing shape; and

a plurality of conformal gas envelopes within said outer shell, wherein each of said conformal gas envelopes is inflatable to form a chamber having at least one flat side, wherein each of said conformal gas envelopes stores helium, and wherein said helium at least substantially fills said outer shell.

20. The airfoil of claim 19, further comprising structural elements within said outer shell that restrict the horizontal expansion of said conformal gas envelopes.

21. The airfoil of claim 19, wherein said gas envelopes when inflated support the shape and rigidity of said outer shell.

22. The airfoil of claim 19, wherein said conformal gas envelopes are made out of a thin, non-porous, and lightweight material.

23. The airfoil of claim 19, wherein said conformal gas envelopes provide buoyancy lift to said hybrid airship.

24. An airfoil for a hybrid airship, said airfoil comprising:

an outer shell having a high-aspect ratio wing shape when inflated; and

a plurality of independent cylindrical gas envelopes within said outer shell, wherein each of said cylindrical gas envelopes stores helium, and wherein said cylindrical gas envelopes do not expand or contract with altitude change.

25. The airfoil of claim 24, further comprising an electrically driven impeller that provides pressurized air, wherein said pressurized air keeps said cylindrical gas envelopes inflated after said helium contained within said cylindrical gas envelopes leaked out.

26. The airfoil of claim 24, wherein the outer shell is a semi-rigid outer shell covering said cylindrical gas envelopes.

27. The airfoil of claim 24, wherein the outer shell is a rigid outer shell covering said cylindrical gas envelopes.

28. An unmanned reconnaissance aerial vehicle, comprising:

an outer shell including an upper skin, a lower skin, a rounded leading edge and a sharp trailing edge, wherein said outer shell is made out of a semi-rigid material, wherein said outer shell is inflatable to a wing shape having a high-aspect ratio and a thick airfoil cross-section and defines an internal volume when inflated;

a plurality of vertical tails located along said trailing edge;

a plurality of cylindrical gas envelopes within said internal volume, wherein said gas envelopes receive and store helium and provide buoyancy lift to said aerial vehicle;

an all-electric propulsion system including a plurality of propulsion pods located along said trailing edge, a high energy density power storage system located within said internal volume, a photovoltaic array located on said upper skin, and a power conditioning unit located within said internal volume, wherein each of said propulsion pods includes a low Reynolds number propeller driven by an electric motor, wherein said power storage system includes an energy storage medium selected from the group of lithium-ion batteries and capacitor banks, wherein said power conditioning unit distributes the electrical power between said photovoltaic array, said energy storage system, and said electric motor, and wherein said all-electric propulsion system is operable to provide aerodynamic lift to said aerial vehicle; and

a plurality of reservoir gas envelopes, wherein said reservoir gas envelopes receive excess helium from said cylindrical gas envelopes during an ambient atmospheric pressure decrease.

29. The unmanned reconnaissance aerial vehicle of claim 28, wherein said propellers are used to steer said aerial vehicle through differential thrusting.

30. The unmanned reconnaissance aerial vehicle of claim 28, further comprising an avionics suite located within said internal volume of said outer shell, wherein said avionics suite is capable of satellite communications and of line-of-sight communications.

31. The unmanned reconnaissance aerial vehicle of claim 28, wherein said electric motor receives power from said power storage system during nighttime hours.

32. The unmanned reconnaissance aerial vehicle of claim 28, wherein said photovoltaic array provides power to said electric motors during daylight hours.

33. The unmanned reconnaissance aerial vehicle of claim 28, wherein said photovoltaic array continuously recharges said power storage system.

34. A method for using a high-aspect ratio hybrid airship as an unmanned reconnaissance aerial vehicle, including the steps of:

providing a high-aspect ratio hybrid airship including an all-electric propulsion system;

preparing said hybrid airship for launch;

launching said hybrid airship using buoyancy lift alone;

letting said hybrid airship ascend vertically to an equilibrium altitude;

transitioning said hybrid airship to forward flight by activating said propulsion system;

bringing said hybrid airship up to an operational altitude using said buoyancy lift and aerodynamic lift; and

moving said hybrid airship to a theater of operations using mainly said aerodynamic lift.

35. The method for using a high-aspect ratio hybrid airship as an unmanned reconnaissance aerial vehicle of claim 34, further comprising the steps of:

assigning said hybrid airship to provide surveillance and reconnaissance capability;

establishing satellite communication between said hybrid airship and a strategic satellite;

establishing line-of-sight communications between said hybrid airship and a ground station;

cruising with said hybrid airship over said theater of operations for an extended period of time; and

providing uninterrupted intelligence, surveillance, and reconnaissance information with said hybrid airship over an extended period of time.

36. The method for using a high-aspect ratio hybrid airship as an unmanned reconnaissance aerial vehicle of claim 34, wherein said operational altitude is at least about 100,000 ft.

37. The method for using a high-aspect ratio hybrid airship as an unmanned reconnaissance aerial vehicle of claim 34, wherein said extended period of time is at least about 1 year.

38. The method for using a high-aspect ratio hybrid airship as an unmanned reconnaissance aerial vehicle of claim 34, further comprising the step of:

providing helium filled gas envelopes integrated within said hybrid airship to provide said buoyancy lift.

39. The method for using a high-aspect ratio hybrid airship as an unmanned reconnaissance aerial vehicle of claim 34, further comprising the step of:

providing said aerodynamic lift with said propulsion system.

40. The method for using a high-aspect ratio hybrid airship as an unmanned reconnaissance aerial vehicle of claim 34, further comprising the steps of:

providing a photovoltaic array, a high energy density power storage system, a plurality of a low Reynolds number propellers, and a plurality of electric motors integrated within said propulsion system;

providing power to said electric motor with said photovoltaic array during daylight hours;

providing power to said electric motor with said power storage system during nighttime hours; and

continuously recharging said power storage system with said photovoltaic array.