Claims
- 1. A wing, comprising:
a body having adequate camber to achieve a lift coefficient of approximately 1.5 at the Reynolds number experienced by flexible-winged stratospheric aircraft, the body defining a leading edge and a trailing edge, wherein the body defines a trailing edge including at least one feature from the group of a reflexed trailing edge and a flapped trailing edge, and wherein the at least one feature of the trailing edge provides the body with a pitching moment greater than or equal to zero in spite of the camber; and an extendable slat at the leading edge of the body, wherein when the slat is extended, it permits the maximum coefficient of lift of the wing to be increased by more than 0.3 at airspeeds just above the stall speed, and wherein when the slat is not extended, it becomes part of a low-drag airfoil otherwise defined by the body's camber.
- 2. The wing of claim 1, wherein the body is characterized by an aspect ratio of at least 20; and wherein when body is not configured with additional pitch-angle stabilization devices.
- 3. An aircraft, comprising:
a flying wing extending laterally to two ends from a center point, substantially without a fuselage or an empennage, wherein the wing is swept, having a relatively constant chord; a power module configured to provide power for the aircraft; and a support structure including a plurality of supports, wherein the supports form a tetrahedron having comers in supportive contact with the wing at points laterally intermediate between the center point and each end, and wherein the tetrahedron also has a corner in supportive contact with the wing's center point; wherein the wing is configured with a highly cambered airfoil and with reflex at a trailing edge of the wing; and wherein the wing is configured with a slat.
- 4. The aircraft power system of claim 3, and further comprising a second power module configured to provide power for the aircraft, wherein the first and second power modules are located laterally along the wing at approximately the location where the tetrahedron comers are in supportive contact with the wing at points laterally intermediate between the center point and each end.
- 5. An aircraft power system for generating power form a reactant, comprising:
a fuel cell configured to generate power using a gaseous form of the reactant, the fuel cell being configured to operate at a power-generation rate requiring the gaseous reactant to be supplied at an operating-rate of flux; and a tank configured for containing a liquid form of the reactant, wherein the tank includes a heat source for increasing a boiling-rate of the reactant; wherein the tank is configured to supply the reactant in gaseous form to the fuel cell at a rate determined by the boiling-rate of the reactant; and wherein the heat source is configured to increase the boiling rate ofthe reactant to a level appropriate to supply the gaseous reactant to the fuel cell at substantially the operating-rate of flux.
- 6. The aircraft power system of claim 5, wherein the power system is configured for use in predetermined ambient conditions having a higher temperature than the temperature of the liquid reactant, and wherein the tank in insulated such that the boiling rate of the liquid reactant due to heat flux through the insulation is lower than the boiling-rate necessary to supply the gaseous reactant to the fuel cell at substantially the operating-rate of flux.
- 7. The aircraft power system of claim 6, wherein the power system is configured for use in stratospheric flight conditions.
- 8. The aircraft power system of claim 5, wherein the tank is configured to contain cryogenic hydrogen, and where the fuel cell is configured for a reactant of gaseous hydrogen.
- 9. The aircraft power system of claim 5, wherein the heat source is an electrical heating element.
- 10. The aircraft power system of claim 5, wherein the tank comprises:
an inner aluminum tank liner having an outer carbon layer; an outer aluminum tank liner having an outer carbon layer; and connectors extending between the inner and outer aluminum tank liners to maintain their relative positions with respect to each other; wherein the volume between the inner and outer tank liners is evacuated to minimize heat transfer between the contents of the tank and the outside environment; and wherein the connectors are configured with holes in their walls to minimize direct heat-conduction between the contents of the tank and the outside environment.
- 11. A stratospheric aircraft to be powered by a reactant, comprising:
an airframe configured for stratospheric flight; and a power system for generating power form the reactant, the power system including:
a fuel cell configured to generate power using a gaseous form of the reactant, the fuel cell being configured to operate at a power-generation rate requiring the gaseous reactant to be supplied at an operating-rate of flux; and a tank configured for containing a liquid form of the reactant, wherein the tank includes a heat source for increasing a boiling-rate of the reactant; wherein the tank is configured to supply reactant to the fuel cell at a rate determined by the boiling-rate of the reactant; and wherein the heat source is configured to increase the boiling rate ofthe reactant to a level appropriate to supply the gaseous reactant to the fuel cell at substantially the operating-rate of flux.
- 12. A method of supplying a gaseous reactant to a fuel cell at a desired operating-rate of flux, comprising:
providing the reactant in liquid form in a tank configured for containing the liquid form of the reactant, wherein the tank includes a heat source for increasing a boiling-rate of the reactant, and wherein the tank is configured to supply the reactant to the fuel cell at a rate determined by the boiling-rate of the reactant; and triggering the heat source to supply heat to increase the boiling rate of the reactant to a level appropriate to supply the resulting gaseous reactant to the fuel cell at substantially the operating-rate of flux.
- 13. An aircraft, comprising:
a hydrogen source; an oxygen source; and a fuel cell configured to combine hydrogen from the hydrogen source and oxygen from the oxygen source to generate power, wherein the fuel cell is configured to combine the hydrogen and the oxygen at less than one atmosphere of pressure.
- 14. The aircraft of claim 13, and further comprising an aircraft engine configured to provide thrust from the power generated by the fuel cell.
- 15. The aircraft of claim 13, wherein the aircraft is configured to operate in conditions equivalent to an altitude of 55,000-70,000 feet.
- 16. The aircraft of claim 13, wherein the fuel cell is configured to internally operate at approximately 2-3 psia.
- 17. An aircraft as recited in any of claims 11 and 13-16, and further comprising wing-mounted solar cells configured to support the fuel cell or battery power of the aircraft when the sun is illuminating the plane.
Parent Case Info
[0001] The present application claims priority from two U.S. provisional patent applications, Ser. No. 60/194,137, filed Apr. 3, 2000, and Ser. No. 60/241,713, filed Oct. 18, 2000, which are both incorporated herein by reference for all purposes.
Provisional Applications (2)
|
Number |
Date |
Country |
|
60194137 |
Apr 2000 |
US |
|
60241713 |
Oct 2000 |
US |