Hydrogen powered aircraft

• US 8,011,616 B2
• Filed: 10/05/2007
• Issued: 09/06/2011
• Est. Priority Date: 04/03/2000
• Status: Expired due to Fees

• Current Assignee: Aerovironment
• Original Assignee: Aerovironment
• Inventors: Hibbs, Bart D., Curtin, Robert F., MacCready, Paul B.
• Primary Examiner(s): Dinh; Tien
• Assistant Examiner(s): Green; Richard R
• Application Number:
  US11/973,092
• Publication Number:
  US 20080203219A1
• Time in Patent Office: 1,432 Days
• Field of Search: 244/59, 244/53.R, 244/62, 244/58
• US Class Current: 244/59
• CPC Class Codes: B64C 1/26 Attaching the wing or tail units or stabilising surfaces
• CPC Class Codes: B64C 3/10 Shape of wings
• CPC Class Codes: B64C 3/14 Aerofoil profile
• CPC Class Codes: B64C 39/024 of the remote controlled vehicle type, i.e. RPV
• CPC Class Codes: B64C 39/10 All-wing aircraft
• CPC Class Codes: B64C 9/24 by single flap
• CPC Class Codes: B64D 2041/005 Fuel cells
• CPC Class Codes: B64D 27/02 Aircraft characterised by the type or position of power plants fuselages specially adapted for mounting power plants B64C1/16; wings specially adapted for power plants B64C3/32
• CPC Class Codes: B64D 27/24 using steam or spring force jet aircraft B64D27/16
• CPC Class Codes: B64D 37/30 Fuel systems for specific fuels
• CPC Class Codes: B64U 10/25 Fixed-wing aircraft VTOL aircraft B64U10/20
• CPC Class Codes: B64U 2101/20 for use as communications relays, e.g. high-altitude platforms
• CPC Class Codes: B64U 2201/10 autonomous, i.e. by navigating independently from ground or air stations, e.g. by using inertial navigation systems [INS]
• CPC Class Codes: B64U 2201/20 Remote controls
• CPC Class Codes: B64U 30/10 Wings
• CPC Class Codes: B64U 30/40 Empennages, e.g. V-tails foldable or collapsible UAVs B64U20/50
• CPC Class Codes: B64U 50/13 using external fans or propellers
• CPC Class Codes: B64U 50/19 using electrically powered motors
• CPC Class Codes: B64U 50/31 generated by photovoltaics
• CPC Class Codes: B64U 50/32 generated by fuel cells
• CPC Class Codes: B64U 70/60 : Take-off or landing of UAVs from a runway using their own power
• CPC Class Codes: Y02T 50/10 : Drag reduction
• CPC Class Codes: Y02T 50/30 : Wing lift efficiency
• CPC Class Codes: Y02T 50/40 : Weight reduction
• CPC Class Codes: Y02T 50/60 : Efficient propulsion technologies, e.g. for aircraft
• CPC Class Codes: Y02T 90/40 : Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

Disclosed is an aircraft, configured to have a wide range of flight speeds, consuming low levels of power for an extended period of time, while supporting a communications platform with an unobstructed downward-looking view. The aircraft includes an extendable slat at the leading edge of the wing, and a reflexed trailing edge. The aircraft comprises a flying wing extending laterally between two ends and a center point. The wing is swept and has a relatively constant chord. The aircraft also includes a power module configured to provide power via a fuel cell. The fuel cell stores liquid hydrogen as fuel, but uses gaseous hydrogen in the fuel cell. A fuel tank heater is used to control the boil-rate of the fuel in the fuel tank. The fuel cell compresses ambient air for an oxidizer, and operates with the fuel and oxidizer at pressures below one atmosphere. The aircraft of the invention includes a support structure including a plurality of supports, where the supports form a tetrahedron that affixes to the wing.

Claims

1. An aircraft, comprising:

a hydrogen source;

an oxygen source;

one or more aircraft engines configured to provide all necessary thrust for the aircraft to fly; and

a fuel cell configured to react hydrogen from the hydrogen source with oxygen from the oxygen source to generate power, wherein the fuel cell is configured to react the hydrogen with the oxygen, each being supplied at reaction pressures of less than one atmosphere absolute;

wherein power generated by the fuel cell powers the one or more aircraft engines; and

wherein the fuel cell is further configured to provide sufficient power for the one or more aircraft engines to enable the aircraft to loiter at altitude with the hydrogen and the oxygen being supplied for reaction in the fuel cell at reaction pressures of less than one atmosphere absolute;

wherein the fuel cell is configured to react the hydrogen with the oxygen at pressures of approximately 2-3 psia;

and further comprising a control system configured to actively control and vary the pressures at which the hydrogen and oxygen are supplied for reaction in the fuel cell;

wherein the control system is configured to actively control the reaction pressures of the fuel cell based on the altitude of the aircraft.

2. The aircraft of claim 1, wherein the aircraft is configured for continuous operation in conditions equivalent to an altitude of 55,000-70,000 feet.

3. The aircraft of claim 1, and further comprising solar cells configured to provide power to the aircraft when the sun illuminates the solar cells.

4. The aircraft of claim 1, wherein the control system is configured to actively control and vary the reaction pressures of the fuel cell based on the power requirements of the aircraft.

5. The aircraft of claim 1, wherein the control system is configured to actively control and vary the reaction pressures of the fuel cell such that fuel is reacted at the minimum rate necessary to meet a power-generation requirement.

6. The aircraft of claim 5, wherein the control system is configured to actively control and vary both the rate at which fuel is supplied and the pressure at which oxidizer is supplied.