US-12617519-B2 - Airship with self-ballasting airframe

Abstract

The invention features an apparatus for airborne transport of cargo. Such an apparatus includes a controller and an airship having a hull, an airframe that supports the hull, and at least one ballast chamber. The controller is configured to actively ballast the airship by causing the ballast chamber to contain a variable mass of air. The controller thus controls the mass or weight of air in each ballast chamber. In some embodiments, the ballast chamber's mass is the sum of a fixed mass and a variable mass. The variable mass is that of air that has been pressurized by some variable amount to a pressure above atmospheric pressure. The controller causes the variable mass to change by changing the number of air molecules in the ballast chamber, either by causing that number to increase or decrease.

Inventors

• David James Prum
• Gregory Joseph Opas

Assignees

• David James Prum
• Gregory Joseph Opas

Dates

Publication Date

20260505

Application Date

20221207

Claims (19)

1. 1 . An apparatus for airborne transport of cargo, said apparatus comprising a controller, an airship having a hull, and an airframe, a portion of which supports at least a portion of said hull, wherein said airframe comprises a ballast chamber, said ballast chamber having a variable mass, wherein said controller is configured to vary said ballast chamber's mass, wherein said ballast chamber is one of a plurality of ballast chambers, each of said ballast chambers having a variable mass, wherein said controller is configured to vary the mass of each of said ballast chambers, and wherein said ballast chambers comprise longitudinal ballast chambers that extend along an axis of said airship and toroidal ballast chambers having centers that intersect said axis, wherein each of said ballast chambers comprises a bladder that is impermeable to air and a jacket that encloses said bladder to provide radial support to said bladder.
2. 2 . The apparatus of claim 1 , wherein said ballast chamber's mass comprises a fixed mass and a variable mass, wherein said variable mass comprises compressed air, and wherein said controller is configured to change said variable mass by causing a change in pressure of said compressed air.
3. 3 . The apparatus of claim 1 , further comprising a plenum filled with compressed air and an intake valve that connects said ballast chamber to said plenum, wherein said controller is configured to open said intake valve to increase said ballast chamber's mass.
4. 4 . The apparatus of claim 1 , further comprising a compressor that draws air from outside said airship, compresses said air, and fills a plenum with compressed air, wherein said controller causes said ballast chamber to fill with air from said plenum, thereby increasing said ballast chamber's mass.
5. 5 . The apparatus of claim 1 , further comprising a bleed valve that controls gas flow between said ballast chamber and air through which said airship travels, wherein said controller is configured to open said bleed valve to reduce said ballast chamber's mass.
6. 6 . The apparatus of claim 1 , wherein said ballast chamber comprises a bladder made of a urethane and a jacket that encloses said bladder, said jacket comprising polyester.
7. 7 . The apparatus of claim 1 , wherein said airship comprises a bow and a stern, wherein said ballast chamber is a bow ballast chamber, wherein said bow ballast chamber is located at said bow of said airship, wherein said plurality of ballast chambers further comprises a stern ballast chamber having a variable mass, wherein said stern ballast chamber is located at said stern of said airship, and wherein said controller is configured to vary masses of said bow and stern ballast chambers to control pitch of said airship.
8. 8 . The apparatus of claim 1 , wherein each of said ballast chambers comprises a variable mass and wherein said controller is configured to vary the mass of each of said ballast chambers.
9. 9 . The apparatus of claim 1 , wherein said ballast chamber comprises a gas-impermeable bladder and a jacket that encloses said gas-impermeable bladder to provide radial support to the bladder.
10. 10 . The apparatus of claim 1 , wherein said airship further comprises a bow sphere and a stern sphere disposed at a bow and stern, respectively, of said airship, and wherein said bow sphere and said stern sphere provide support for said longitudinal ballast chambers of said frame.
11. 11 . The apparatus of claim 1 , wherein said ballast chamber comprises a metal bladder and a jacket that surrounds said bladder and provides resistance against rupture thereof.
12. 12 . A method comprising controlling lift of an airship having an airframe having a portion that supports at least a portion of a hull thereof, wherein said ballast chamber is one of a plurality of ballast chambers, each of said ballast chambers having a variable mass, wherein said controller is configured to vary the mass of each of said ballast chambers, and wherein said ballast chambers comprise longitudinal ballast chambers that extend along an axis of said airship and toroidal ballast chambers having centers that intersect said axis, wherein each of said ballast chambers comprises a bladder that is impermeable to air and a jacket that encloses said bladder to provide radial support to said bladder, wherein controlling said lift comprises increasing a mass of a ballast chamber aboard said airship.
13. 13 . The method of claim 12 , wherein increasing said mass comprises admitting compressed air into said ballast chamber.
14. 14 . The method of claim 12 , wherein controlling said lift further comprises decreasing said mass of said ballast chamber.
15. 15 . The method of claim 12 , wherein controlling said lift further comprises causing compressed air in said ballast chamber to be bled out.
16. 16 . The method of claim 12 , wherein controlling said lift comprises determining that a change in lift is required, determining that said change in lift is a positive change, and reducing said mass of said ballast chamber.
17. 17 . The method of claim 13 , wherein controlling said lift comprises determining that a change in lift is required, determining that said change in lift is a negative change, and increasing said mass of said ballast chamber.
18. 18 . The method of claim 12 , wherein increasing said mass of said airframe comprising filling a ballast chamber in said airframe with compressed air.
19. 19 . The method of claim 12 , wherein said airframe has a mass and wherein increasing said mass of said ballast chamber comprises increasing said airframe's mass.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a national phase under 35 USC 371 of International Application No. PCT/US2022/052089, filed Dec. 7, 2022, which claims priority to and the benefit of the filing date of U.S. Application No. 63/286,733, filed on Dec. 7, 2021, the contents of all of which are hereby incorporated by reference in their entirety. FIELD OF INVENTION This invention relates to air transport, and in particular, to lighter-than-air vehicles, also known as “airships.” BACKGROUND When transporting cargo by air, it is usual to create an upwardly-directed force. Initially, this lifting force is greater than the cargo's weight. This permits upward acceleration until some desired altitude is reached. At some point, the cargo will have been lifted to the desired altitude, as a result, the lifting force must be reduced to an extent that stops upward acceleration but prevents downward acceleration due to gravity. Most of the cargo's voyage will be in this state. Then, as the cargo approaches its destination, it is usual to reduce the lifting force, thereby causing a controlled downward acceleration. For those aircraft that rely on airfoils to produce lift, it is a simple matter to control the lifting force by controlling forward thrust and angle-of-attack in concert. For those aircraft that rely on buoyancy, controlling the lifting force is not quite as simple. In such cases, the lifting force depends on the relationship between the density of a gas that is within an airship, the total mass of the airship, and the density of the air that the airship travels through. To control lift, one controls this relationship. Because of difficulties inherent in controlling atmospheric pressure, it is usual to control either the density of the gas within the airship or the total mass of the airship. SUMMARY The invention is based on the use of air, the medium through which the airship moves, for controlling the average density of gas within the airship, thereby providing a basis for controlling lifting force. In one aspect, the invention features an apparatus for airborne transport of cargo. Such an apparatus includes a controller and an airship having a hull, an airframe that supports the hull, and at least one ballast chamber. The controller is configured to actively ballast the airship by causing the ballast chamber to contain a variable mass of air. The controller thus controls the mass or weight of air in each ballast chamber. In some embodiments, the ballast chamber's mass is the sum of a fixed mass and a variable mass. The variable mass is that of air that has been pressurized by some variable amount to a pressure above atmospheric pressure. The controller causes the variable mass to change by changing the number of air molecules in the ballast chamber, either by causing that number to increase or decrease. Other embodiments include a plenum filled with compressed air and an intake valve that connects the ballast chamber to the plenum. In such embodiments the controller opens the intake valve to increase the ballast chamber's mass. Still other embodiments include a compressor that draws air from outside the airship, compresses the air, and fills a plenum with compressed air. In such embodiments, the controller causes the ballast chamber to fill with air from the plenum. This increases the ballast chamber's mass. Also among the embodiments are those that include a bleed valve that controls gas flow between the ballast chamber and air through which the airship travels. In such embodiments, the controller opens the bleed valve to reduce the ballast chamber's mass. Embodiments also include those in which the ballast chamber includes a bladder that is impermeable to air and a jacket that encloses the bladder to provide radial support to the bladder. Among these are embodiments in which the bladder is made of a gas impermeable material, such as urethane or mylar, and the jacket comprises a woven textile material. Embodiments include those in which the material's fibers comprise polyester aramid or carbon nanotube fibers and yarns. In other embodiments, the bladder is made of a metal to provide impermeability to gas. A surrounding jacket then provides resistance against rupture. Examples of a suitable metal are light metals such as aluminum. In still other embodiments, the jacket is made of a material or a combination of materials having a strength-to-weight ratio that is sufficient to enable the bladder to sustain a selected internal pressure while being light enough to permit the airship to attain positive buoyancy. Still other embodiments are those in which the ballast chamber is a bow ballast chamber and the frame includes a stern ballast chamber that also has a variable mass. Among these are embodiments in which the controller varies masses of the bow and stern ballast chambers to control the airship's pitch. In some embodiments, the ballast chamber is one of a plurality of ballast chambers.