초록 ▼

The present invention is a variable geometry lighter-than-air (LTA) aircraft that is adapted to morph its shape from a symmetric cross-section buoyant craft to an asymmetric lifting body and even to a symmetric zero lift configuration. The basic structure is a semi rigid airship with movable longero

The present invention is a variable geometry lighter-than-air (LTA) aircraft that is adapted to morph its shape from a symmetric cross-section buoyant craft to an asymmetric lifting body and even to a symmetric zero lift configuration. The basic structure is a semi rigid airship with movable longerons. Movement of the longerons adjusts the camber of the upper and/or lower surfaces to achieve varying shapes of the lifting-body. This transformation changes both the lift and drag characteristics of the craft to alter the flight characteristics. The transformation may be accomplished while the craft is airborne and does not require any ground support equipment.

대표청구항 ▼

1. An aircraft comprising: a flexible envelope that encloses a base structure, a pair of upper longeron rods and a pair of lower longeron rods with each longeron rod pivotally connected to the base structure, and a pair of envelope expansion arms;each upper longeron rod in the pair of upper longeron

1. An aircraft comprising: a flexible envelope that encloses a base structure, a pair of upper longeron rods and a pair of lower longeron rods with each longeron rod pivotally connected to the base structure, and a pair of envelope expansion arms;each upper longeron rod in the pair of upper longeron rods further including a curved shape extending between a fore end and an aft end with a vertex at the local maximum of the curved shape, wherein the curved shape extends away from a lateral axis of the aircraft to support the flexible envelope;each upper longeron rod in the pair of upper longeron rods further including being in communication with an upper translation assembly, the upper translation assembly adapted to pivot the upper longeron rod, thereby moving the vertex of the upper longeron rod towards or away from the lateral axis of the aircraft to alter a thickness of the aircraft;each lower longeron rod in the pair of lower longeron rods further including a curved shape extending between a fore end and an aft end with a vertex at a local maximum of the curved shape, wherein the curved shape extends away from the lateral axis of the aircraft to support the flexible envelope;each lower longeron rod in the pair of lower longeron rods further including being in communication with a lower translation assembly, the lower translation assembly adapted to pivot the lower longeron rod, thereby moving the vertex of the lower longeron rod towards or away from the lateral axis of the aircraft to alter the thickness of the aircraft; andthe pair of envelope expansion arms including a first envelope expansion arm located at least partially on a starboard side of the aircraft and a second envelope expansion arm located at least partially on a port side of the aircraft. 2. The aircraft of claim 1, wherein the base structure includes a central core extending generally parallel to a central longitudinal axis of the aircraft, a leading edge strut extending in a direction perpendicular to and in communication with the central core, a trailing edge strut extending in a direction perpendicular to and in communication with the central core, a port side outrigger extending in a direction parallel to the central core and in communication with the leading and trailing edge struts, and a starboard side outrigger extending in a direction parallel to the central core and in communication with the leading and trailing edge struts. 3. The aircraft of claim 2, further including the flexible envelope sealing around a perimeter of an open front end of the core and also sealing around a perimeter an open back end of the core creating an open fluidic passage through the flexible envelope via the central core. 4. The aircraft of claim 1, further comprising a structural connection point having a first fixed connection attached to an outrigger, a second fixed connection attached to a strut, a first pivoting connection attached to one of the upper longeron rods, a second pivoting connection attached to one of the lower longeron rods, and a third pivoting connection attached to one of the envelope expansion arms. 5. The aircraft of claim 3, further including a propulsion system secured within the central core, such that the propulsion system receives incoming air through the open front end of the core to generate thrust, which exits the open back end of the core. 6. The aircraft of claim 1, wherein the pair of upper longeron rods includes a port side longeron rod and a starboard side longeron rod and the pair of lower longeron rods includes a port side lower longeron rod and a starboard side lower longeron rod. 7. The aircraft of claim 1, wherein the envelope expansion arm is an anisotropic beam including two or more composite rods with cross members having a predetermined spring constant embedded into the structure, one of the composite rods is pivotally attached to the aircraft and one or more of the composite rods is anchored against the pivot structure to provide a tension force. 8. The aircraft of claim 1, further including a span that increases when the envelope expansion arms are in an expanded position and decreases when the envelope expansion arms are in a retracted position. 9. The aircraft of claim 1, further comprising a lighter-than-air configuration, the lighter-than-air configuration including: each of the upper longeron rods is positioned so that each respective vertex is a maximum distance from the lateral axis of the aircraft, and each of the lower longeron rods is positioned so that each respective vertex is a maximum distance from the lateral axis of the aircraft, thereby increasing the thickness of the aircraft; andeach envelope expansion arm is in a retracted position and the span of the aircraft is at a minimum value. 10. The aircraft of claim 1, further comprising a gas storage and retrieval system adapted to house, distribute, and retrieve lighter-than-air gas. 11. The aircraft of claim 1, further including a propulsion system having an electrical generator system adapted to convert wind energy into electrical energy while the aircraft is in a lighter-than-air configuration. 12. The aircraft of claim 1, wherein each envelope expansion arm further includes: an adjustable length;a biasing member imparting a constant bias force directed away from the longitudinal axis of the aircraft to increase the length of each envelope expansion arm which in turn increases the span of the aircraft;a retracted position in which the length of the envelope expansion arm is at a minimum value and an expanded position in which the length of the envelope expansion arm is at a maximum value;the retracted position is achieved when a tension force in the flexible envelope overcomes the constant bias force that results from pivoting the vertices of the upper and lower longerons away from the lateral axis of the aircraft; andthe expanded position is achieved when the tension force in the flexible envelope is overcome by the constant bias force that results from pivoting the vertices of the upper and lower longerons towards the lateral axis of the aircraft.