System, method and apparatus for widespread commercialization of hydrogen as a carbon-free alternative fuel source

Abstract

A lighter than air craft having an airframe that has at least one tank in the airframe for holding compressed or liquid hydrogen or helium and at least one compartment in the airframe holding an inflatable bladder. The inflatable bladder can be inflated with hydrogen or helium gas from the first tank. There is a vent in the compartment allowing air to exit the compartment when the bladder is inflated and allowing air to enter the compartment when the bladder is deflated. Inflating and deflating the bladder partially controls buoyancy of the craft. Inflating bladders in compartments fore and aft controls pitch and trim.

Claims

1. A lighter-than-air craft comprising: an airframe having an outer surface; a first tank in the airframe for holding compressed or liquid hydrogen or helium; a plurality of compartments in the airframe, each holding an inflatable bladder, wherein said inflatable bladder can be inflated with hydrogen or helium gas from the first tank; a vent in the compartment allowing air to exit said compartment when the bladder is inflated and allowing air to enter the compartment when the bladder is deflated; wherein, inflating and deflating the bladder partially controls buoyancy of said lighter-than-air craft; and wherein, inflating and deflating bladders in different compartments fore and aft partially control pitch and trim.

2. The craft of claim 1 further comprising a second tank and a pump connecting the bladder to the second tank, wherein gas from the bladder is stored in the second tank as the bladder is deflated.

3. The craft of claim 2 further comprising a high pressure pump connected between the second tank and the first tank, wherein gas from the first tank is compressed and injected into the first tank.

4. The craft of claim 1 further comprising at least one engine providing thrust.

5. The craft of claim 3 further comprising at least one engine providing thrust, wherein the first and second tanks contain hydrogen and said engine is fueled with hydrogen from the second tank.

6. The craft of claim 4 wherein said engine can pivot to point in a plurality of directions away from said craft.

7. The craft of claim 5 wherein said engine can pivot to point in a plurality of directions away from said craft.

8. The craft of claim 1 further comprising at least one airfoil.

9. The lighter-than-air craft of claim 1 wherein said outer surface is a fluorocarbon polymer.

10. An airship having an airframe comprising: a first tank in the airframe holding compressed or liquid hydrogen or helium; a plurality of compartments in the airframe, each holding an inflatable bladder, wherein said inflatable bladder can be inflated with hydrogen or helium lift gas from the first tank; a vent in the compartment allowing air to exit said compartment when the bladder is inflated and allowing air to enter the compartment when the bladder is deflated; a second tank in the airframe; a pump connected between the bladder and the second tank, wherein gas from the bladder is pumped into the second tank to deflate the bladder; wherein, inflating and deflating the bladder partially controls buoyancy of said airship; and wherein, inflating and deflating bladders in different compartments fore and aft partially controls pitch and trim.

11. The airship of claim 10 further comprising at least one engine providing thrust.

12. The airship of claim 11 wherein said engine can pivot to point in a plurality of directions away from said craft.

13. The airship of claim 10 further comprising at least one airfoil.

14. The airship of claim 10 further comprising a high pressure pump connected between the second tank and the first tank, wherein gas from the second tank is compressed and injected into the first tank.

15. The airship of claim 12 wherein the first and second tank contain hydrogen and the engine uses hydrogen from the first or second tank as fuel.

16. A lighter-than-air craft comprising: an airframe: a plurality of compartments in said airframe, each compartment vented to the atmosphere; each of said compartments containing an inflatable bladder; at least one high pressure tank containing lift gas; each of said bladders being gas connected to said at least one high pressure tank, wherein at least some of said bladders can be inflated in the compartments by the lift gas to increase lift, and inflated bladders can be deflated to decrease lift; and wherein, different bladders can be inflated fore and aft to control pitch and trim.

17. The craft of claim 16 further comprising at least one low pressure tank connected to at least some of said bladders through at least one pump, wherein the bladders discharge into the low pressure tank through the pump when being deflated.

18. The craft of claim 17 further comprising a second pump between the low pressure tank and the high pressure tank, wherein gas in said low pressure tank is compressed and injected into said high pressure tank.

19. The craft of claim 17 further comprising an engine mounted on the airframe, the engine tiltable to a plurality of angles with respect to the craft, the engine burning hydrogen from either the low pressure tank or the high pressure tank the lift gas is hydrogen.

20. The craft of claim 16 further comprising an engine mounted on the airframe tiltable to a plurality of angles with respect to the craft.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG. 1 is a block flow diagram illustrating how the system of the present invention may be used to produce and transport hydrogen from the place where the gas is generated to the area where the hydrogen is needed as an alternative energy source.

[0017] FIG. 2 depicts an exterior side-view of an embodiment of an airship according to the present invention.

[0018] FIG. 2A shows a possible embodiment of the mounting of a flap.

[0019] FIG. 2B shows an embodiment of the mounting of a rotatable engine.

[0020] FIG. 2C shows the use of a drone device to accomplish docking.

[0021] FIG. 3 is an interior side view of the airship of FIG. 2, showing hydrogen storage compartments and a controlled bladder system.

[0022] FIG. 4 shows a tank/bladder system.

DETAILED DESCRIPTION OF THE INVENTION

[0023] The present invention relates to a system and method of using natural locations where the existence of geothermal, wind, solar, wave, tidal or hydropower-based conditions favor the generation of electricity that can be used to generate hydrogen from water using electrolysis, and then employing specially designed airships to transport that hydrogen gas from the location where the gas is produced to the place where it is needed as an alternative fuel source. Because the airship contains hydrogen gas, which is approximately 14 times lighter than air, the craft can carry quite a substantial payload, which in a preferred embodiment is at least a substantial quantity of hydrogen gas itself as a payload.

[0024] The craft's maneuverability in taking off, landing and changing directions is enhanced through one or more engine mounts that permit the preferably hydrogen-fueled engines to rotate and pivot so that they provide upward or downward thrust, either vertically or at an acceptable angle of ascent or descent, as well as in a lateral plane so that the engines may act like thrusters on a boat.

[0025] Turning to FIG. 1, a block flow diagram can be seen illustrating how in one embodiment, the present invention may be used to produce and transport hydrogen from the place where natural conditions favor the clean, comparatively low cost production of electricity that can be used to generate hydrogen from water via electrolysis, to the area where the hydrogen is needed as an alternative energy source. Block 101 indicates that the first step involves the identification of a location where the natural conditions or features favor comparatively low cost, clean electricity generation.

[0026] There are a number of places where such favorable natural conditions are present. These include places where substantial electricity is presently being generated on a commercial scale, such as in Hawaii, Iceland and Northern California, where molten rock and superheated water and steam occur relatively close to the Earth's surface, or where adequate heat can be tapped such that injected water to the heat source can economically generate electricity, in each such case thereby favoring geothermal production of hydrogen from such electricity in a preferred embodiment of the invention In other embodiments, the location may rely upon favorable conditions for wind generation, such as along the North Sea, the southern tip of South America, the Australian island of Tasmania, and certain locations in North America where relatively continuous high wind velocity is present. Alternatively, it may relate to ideal solar conditions, such as in the Pacific Ocean, south of Hawaii, in the Sahara, the nation of Niger, and certain parts of Australia; as well as locations that are ideally suited to power generation from wave energy, tidal flow production, and hydropower, which power is then converted into hydrogen.

[0027] Block 102 indicates that at one or more of these locations where nature has created features that favor comparatively low cost, clean electricity generation, known technologies are used to generate hydrogen from water using electrolysis. Block 103 illustrates that the hydrogen gas generated by this means will be temporarily stored on site or in close proximity to where it is produced, pending the arrival of a suitable transport vehicle. In step 104, the hydrogen is transported from the place where these natural resources occurwhich is often in a relatively remote locationto places where there is a market need for this alternative energy source.

[0028] As illustrated by blocks 104a through 104d, the preferred method of transporting the hydrogen uses the hydrogen itself to provide propulsion energy for the craft, 104a; and takes advantage of the lighter-than-air quality of the gas to provide lift, 104b, thereby materially reducing the energy needed for transporting the payload. Additionally, the preferred method for transporting the hydrogen also utilizes the hydrogen for all on-board electrical ancillary needs, 104c. Accordingly, through practicing the present invention, the excess hydrogen, 104d, can be delivered to the location where the gas is needed as an alternative energy source with little to no carbon-fuel consumption. In a preferred embodiment of the invention, these attributes are fulfilled by a specially designed airship 200 such as described with regard to FIG. 2, below.

[0029] Once at the desired destination, the excess hydrogen, 104d, can be moved off the airship to storage, illustrated by block 105. From this storage location, the hydrogen can be combusted at an electricity generating plant or distributed to other end use locations using conventional means such as pressurized and non-pressurized portable containers and pipelines, illustrated by block 106, to both resellers and/or end users of the clean energy source. This step is in turn illustrated by block 107. Block 108, entitled Lighter-than-air vehicle usage for transportation of cargo payload on return flight, illustrates another principle of one preferred embodiment, which involves utilizing the craft's return flights for the purpose of carrying passengers and/or a cargo payload, as illustrated by line 109, particularly where such payload may be useful to fulfilling particular needs associated with the location of the natural features that favor low cost clean electricity generation referenced in block 101. In particular, a return flight (or any flight) can carry water, food or other cargo necessary for life from a location where it is abundant to a location where it is needed.

[0030] Turning next to FIG. 2, it will be observed that FIG. 2 depicts an exterior side view of an embodiment of an airship 200 according to the present invention. The airship 200 preferably includes an exterior shell 201 having a front portion 202, a rear portion 203 and a main axis 204. According to one embodiment of the airship 200, the exterior skin 201 may be made from a carbon fiber composite, film laminate or an equivalent material such as KEVLAR or other high-strength ballistic nylon, and/or may be coated with fluorocarbon polymer such as TEFLON or other similar materials that will minimize the overall weight of craft 200 while at the same time providing a protective outer coating and minimal air resistance. KEVLAR and TEFLON are registered trademarks belonging to the DuPont Corporation of Wilmington Del. Any material with suitable properties for forming an exterior skin is within the scope of the present invention.

[0031] Bodies that generate lift, and/or the term lifting bodies, refers to an aircraft configuration where the body of the craft itself (with or without wings) produces lift, such as a fuselage that generates lift without the shape of a typical thin and flat wing structure. Lifting bodies generally minimize the drag and structure of a wing, and provide the best trade-off in terms of maneuverability and aerodynamics. Thus, in a preferred embodiment, the exterior shape of airship 200 will be designed to apply the principles of lifting bodies to conventional dirigible design.

[0032] FIG. 2 also shows one or more optional external flaps, 206a and 206b, located on each side of the craft along main axis 204; and 206c at the rear that can function as an elevator flap. Additionally, one or more optional single rudder, dual rudders or other stabilization methodologies, collectively 207, are located at the rear of the craft or other appropriate locations for enhancing stability and in order to help steer the craft. As illustrated in FIG. 2-A, each external flap 206 is preferably mounted so that it can be rotated around a pivot 208, and raised or lowered according to arrows 209 in order to provide additional lift during ascent and stability during descent of the craft.

[0033] In a particular embodiment of the present invention, the airship 200 may further include one or more external motors, 210, which may be a jet, turbojet, rotary blade, or propeller-type engine that is preferably powered by hydrogen as its energy source (but in alternative embodiments that may be powered by jet fuel, gasoline, diesel or electricity, including from solar cells mounted on the craft's exterior). According to the embodiment illustrated in FIG. 2, external motors 210 may be mounted along the main axis 204, or optionally may be attached to the gondola 205, to one of more or external flaps 206, or to the rear portion 203 of exterior shell 201.

[0034] Another advantage of the airship 200 is that, as illustrated in FIG. 2-B, each external engine 210, can be optionally mounted so that it can be rotated around one or more pivots 211, and turned according to arrows 214. This optional feature will permit external engines 210 to be turned so that the leading edge of the engine 212 can be directed along the main axis 204, perpendicular to that axis for take-off or landing, and at any angle to help speed ascent or descent of the craft. Additionally, in a particular embodiment, external engines 210 may be rotated laterally with the rear edge of the engine 213 directed away from the craft, to help maneuver the airship sideways in the manner achieved by thruster engines in a boat.

[0035] The exterior of the craft 201 may be formed of a substantially rigid material such as carbon fiber or any other suitable light weight material; or alternatively any number of readily available flexible and/or microfiber-based composite materials; or any other hydrogen and helium retentive materials. Although in an alternative embodiment, lighter-than-air craft 200 may employ a semi-rigid design (e.g., employing some internal support such as a fixed keel), in a preferred embodiment, the craft can employ a rigid (e.g., with full skeleton) design. However, unlike the rigid design of older airships such as the Zeppelin, which were constructed with steel members, the internal structural elements employed in carrying out the design for airship 200 will preferably employ materials having the dual qualities of being lightweight and extremely strong, such as carbon fiber or nano-tubes, graphite, aluminum and various composite materials that are well known in modern aeronautical design. Any material that is structurally strong and also light is within the scope of the present invention.

[0036] One of the historical challenges of operating a lighter-than-air craft is to control the ship's landing, particularly in cases where the landing area is tight and/or where weather conditions such as high winds in or near the landing area may make it exceedingly difficult to control a craft having such a large surface area. In order to overcome this challenge, FIG. 2 depicts that the lighter-than-air craft 200 can include a reinforced connector 215 for a lightweight guide-wire cable or tie-line. This optional feature is further illustrated in FIG. 2-C, which shows that guide-wire cable 216 may be physically attached to connector 215 at an appropriate point at or near the front of craft 200.

[0037] A pole higher than at least half the diameter of the craft can be equipped with a gimble on its top that can swivel to any angle. The attachment point 218 can be mechanically coupled to this gimble. Once the lightweight guide-wire 216 engages the attachment 218, a larger diameter tie cable can be fed through the attachment 218. The craft can then be reeled in and tied to the gimble so that it can align itself with the prevailing wind much as a sailboat on an anchor. The aft end of the craft can then be stabilized, either with an additional tie-down or with another pole.

[0038] In order to direct the first guide-wire 216 into the attachment 218, a small, remotely controlled unmanned, aerial vehicle (also known as a UAV or drone craft) or a projectile fired from the airship for the same purpose, such as illustrated by craft 217 may be attached to the other end of guide-wire cable 216; and such UAV may be flown to the landing area where guide-wire 216 can be tied to stationary curb 218, and a hoist (not shown) may used by ground personnel to reel-in and safely secure craft 200. The UAV craft may be flown by wireless techniques such as radio or light, or by fly-by-wire where electrical signals are sent to it using either a small electrical cable that runs along the guide-wire 216 (or that is the guide-wire), or by using a fiber optic cable that runs with the guide-wire 216 (or is the guide-wire). The UAV craft may be piloted from a remote console by the dirigible's pilot or a landing officer. The drone 217 could be made maneuverable using airfoils and powered with a small engine, all as is known in the art. The drone 217 or projectile could contain a video camera, radar or other sensing or navigation device such as GPS. The drone 217 can be configured to hover or fly straight as needed for docking the larger craft. A fired projectile, on the other hand, could be fired into a receiving port that could optionally be equipped with an electromagnetic field. While several methods and techniques for tethering and docking the large craft have been presented, any method of docking or attaching the craft to a tie-down or support is within the scope of the present invention.

[0039] FIG. 2 shows an embodiment of the lighter-than-air craft of the present invention. Many other shapes are possible. In some embodiments, the craft can be cigar-shaped with a pointed or needle nose. The craft can also have a sharply tapering tail. Designs with these features typically have lower drag coefficients that result in higher speeds with lighter engines. To increase the payload on such a design, the craft can be lengthened. FIG. 2 also shows the craft with a gondola 205. The use of a gondola is optional to carry crew, passengers or cargo. In some embodiments of the present invention, all of the payload can be carried in a gondola. In other designs, the craft may have no gondola or a small gondola simply for crew with all most or all the payload being carried inside the main hull. A gondola 205, if used, may be pressurized for high altitude flight (typically flights above 14,000 feet above sea level will require pressurization).

[0040] Now turning to FIG. 3, an interior side view of the embodiment of the airship 200 shown in FIG. 2 can be seen. Inside the craft, one or more hydrogen storage compartments 301a-301n, are preferably alternated with at least one or more chambers or compartments 302a-302n. The hydrogen storage compartments can 301a-301n can be high pressure storage tanks or other storage devices. Thus, whereas the traditional lighter-than-air craft may use a suspended structure generally corresponding to gondola area 205 shown in FIG. 2 for carrying its payload (a technique that can be used with the present invention), in many embodiments of the present invention, storage compartments or tanks 301a-301n are able to be filled with hydrogen, preferably in either a compressed or liquefied form as a payload. Chambers or compartments 302a-302n can contain a system of bladders 305a-305n that are able to be filled with hydrogen or helium to afford the additional lift needed to achieve buoyancy once at the desired flight altitude.

[0041] Each of chambers 302a-302n generally includes an inlet valve or vent, 303a-303n, and an outlet valve or vent, 304a-304n, respectively; however, in many embodiments of the invention, these may be the same, and there may only be one set of openings or vents. The housing of chambers 302a-302n may consist merely of the exterior walls of hydrogen storage compartments 301a-301n and the interior walls of shell 201; however, it is also possible that they can be constructed from a separate flexible liner made of appropriate microfiber-based composite materials or other hydrogen and helium retentive material. As shown in FIG. 3, a bladder system 305a-305n can be disposed inside chambers 302a-302n, respectively, to divide the portion of each such chamber served by the valves or vents. These bladders can be made of flexible microfiber-based composite materials or any other hydrogen and helium retentive materials, but in alternative embodiments may be plates or bags made of polyvinyl chloride, polypropylene, or any other suitable materials. Any hydrogen or helium retentive material may be used to construct the bladder system and is within the scope of the present invention. The bladders 305a-305n, in effect, can act as inflatable bags or accordion type structures using fixed elements and flexible material.

[0042] Generally, each set of compartments 301a-301n can contain at least one high pressure hydrogen tank 301 (as is also shown in FIG. 4) while compartments 302a-302n can contain one or more bladders 305a-305n. One or more, lower pressure hydrogen tanks 306 can be connected to the outlet of each bladder. When additional lift or trim is desired, high pressure hydrogen can be vented or pumped 309 from a high pressure tank into a particular bladder 305 expanding it. As the bladder 305 expands in the compartment or chamber 302, air at ambient pressure is forced out of the compartment. When less lift is desired, a pump 308 can take hydrogen out of the bladder 305 causing the bladder to collapse and force it into the second, lower pressure hydrogen tank 306. In this manner, no hydrogen is mixed with air, vented or wasted. The low pressure hydrogen can simply be saved in the lower pressure tank, transferred to another tank, ducted to engines to as a fuel, or it can be pumped back into the high pressure tank using a second, high pressure pump. As a bladder collapses, air at ambient pressure is drawn in from outside the craft. In an alternative embodiment, the excess hydrogen can also simply be vented to the atmosphere.

[0043] The bladder system described can selectively increase or decrease the ratio of hydrogen to air in the chambers 302 to control the amount of lift the craft achieves at every altitude while ascending and descending taking into consideration the changing atmospheric pressure that naturally occurs when a craft ascends and descends. This feature can be controlled automatically by a computer program running on a typical computer, server or other processor known in the art which can simultaneously monitor external ambient pressure based upon the altitude of the ship, the desired direction and speed of ascent or descent, and the lift being achieved, so as to optimize the flow of hydrogen to and from one or more bladder or accordion chambers.

[0044] The unique configuration of these chambers or compartments, the flexible bladder system and available hydrogen supply will, in conjunction with the outside engines 210, airfoils and the optional computer control, permit the bladder system to be used to adjust the quantity and pressure of the hydrogen or helium gas in the chambers to be sufficient for the overall weight of the craft and its payload (including compressed or liquefied hydrogen in storage tanks) and the desired rate of climb to altitude, descent from altitude, and/or maintaining relatively neutral buoyancy once the desired flight altitude is attained.

[0045] The bladder system described allows simultaneous control of both lift and fore-aft trim. When the craft is not moving horizontally, adjustment of bladders in different parts of the ship allow trim control. After the craft acquires a horizontal speed, trim can also be controlled by the airfoils and engine directions as described. At altitude and speed, the bladders can be set to achieve approximately neutral buoyancy with trim and with part of the lift then being provided by the structure itself according to aeronautical principles with trim being almost exclusively controlled by the airfoils and the engine directions. In general, the craft of the present invention ascends and descends at relatively slow horizontal speeds relying on buoyancy control and moves at high horizontal speeds at altitude for long distance travel relying on airfoils and engines for thrust and/or control.

[0046] In accordance with the principles of the invention, the foregoing system, method and apparatus is capable of lifting an enormous amount of weighton the order of 100 tons (200,000 lbs.) or moreand of transporting its payload of hydrogen or other cargo over long distances to where it is needed with comparatively low cost with negligible to no consumption of carbon-based fuel, and at a speed that is many times faster than via ocean tanker. The craft of the present invention may travel at speeds as high as several hundred miles per hour at high altitudes.

[0047] The present invention has many advantages over the prior art including the fact that the airship is able to land on an area that is only slightly larger than the size of the craft itself and to take off again with only modest ground facilities or refueling. Another advantage is that once the maximum capacity (by volume) of hydrogen storage tanks 301a-301n is reached, the additional lifting capacity of airship 200 may be used to carry a payload of freight and/or passengers in gondola area 205 at nearly zero incremental cost. Yet another advantage is that rather than being required to dead-head return flights, merely by filling hydrogen storage tanks 301a-301n and chambers 302a-302n with a sufficient quantity of hydrogen or helium for the return flight, such flights may be used in a conventional fashion, either for freight or passenger transit using gondola 205 and any cabins or storage holds built into this area.

[0048] In another embodiment of the present invention, some portion or all of storage compartments 301a-301n may be specially adapted to be filled with water. So outfitted, the ship may be utilized counter-cyclical to its use for transporting hydrogen as previously described for moving large quantities of water, such as in connection with areas where climate change has reduced runoff from traditional snowpack or glaciers. In these cases, the airship may be used to serve upstream locations for which there presently exists no economic means of reverse-gravity flow. In such instances, the flexible bladder system of the instant invention or the cylinders dedicated to compressed hydrogen used in other embodiments can be adapted for the purpose of holding large quantities of water or other liquids.

[0049] The present invention is very versatile for widespread commercialization of hydrogen as a carbon-free alternative fuel source in that it can be tailored to accommodate numerous different operations. Thus, for example, whereas a particular embodiment may entail the use of the craft to economically transport payloads of water, the lighter-than-air ship may also be used to transport various cargo payloads. Hence, in the case of the foregoing example of Hawaii, an island blessed with geothermal and wind resources that may fuel the production of hydrogen that could be transported to California for use, on the return flight, the ship may be used to transport tourists and/or large quantities of food and paper goods that are presently being shipped from California to Hawaii. This practice may be applied in any number of ways that is tailored to the particular socio-economic and political-geographic needs.

[0050] Several examples will now be presented in order to illustrate the concepts of the present invention. The scope of the present invention is not limited to the numbers or quantities expressed in these examples. Straight hydrogen gas lift will be first considered, followed by the power required to achieve high speeds at altitude. Simplifying assumptions will be made.

[0051] As part of the first example, consider an airship according to the present invention designed to lift a maximum weight of 400,000 lbs.; cruise at an altitude of 39,000 feet; and maintain a maximum speed of 100 MPH at that altitude. Assume the craft has the shape shown in FIG. 1 with a maximum diameter of 300 feet and a length of 1700 feet. For simplicity in this example, this will be considered to be a cylinder of these dimensions. The volume of such a cylinder is 120,165,919 cubic feet, or approximately 3,402,720 cubic meters.

[0052] Air at sea level has a density of around 1.225 kg/cu meter, and at 39,000 feet, a density of around 0.316406 kg/cu meter according to the standard atmosphere model. Thus, at sea level, 3,402,720 cu. meters of air weighs about 4,168,332 kg, and at 39,000 feet, it weighs about 1,076,641 kg. It is well known that a body possesses lift (positive buoyancy) when the weight of its displacement is greater than its total weight. The total lift force is the weight of its displacement of air minus the total weight.

[0053] Molecular hydrogen gas has a density of around 0.08988 kg/cu meter. Thus, if the entire cylinder was filled with hydrogen gas, the gas would weigh about 305,836 kg. The lift at sea level would be 3,862,496 kg and at 39,000 feet 770,805 kg. This results in a lift of 8,515,339 lbs. at sea level and 1,699,332 lbs. at 39,000 feet for the example given.

[0054] Of course, the ship is not a cylinder as assumed in this example, and the entire structure would not be filled with hydrogen gas. However, it can be seen that even neglecting these simplifying assumptions, at altitudes much greater than 39,000 feet, there is entirely adequate gas lift using this size ship for a total craft weight, including payload, of 400,000 lbs. or greater.

[0055] The next example will consider speed at altitude, again 39,000 feet for this particular case. It is well known that to maintain a particular speed in a fluid, the thrust force must equal the drag force. Drag force is equal to times the drag coefficient times the density times the cross-sectional area times the speed squared. Thus drag, and hence required thrust, increases (or decreases) linearly with density and area, and quadratically with speed.

[0056] The drag coefficient is independent of area, density or speed and is related only to the type of flow and the shape of the body. Since the air density at 39,000 feet is thin, the assumption will be made that the type of flow is laminar with a boundary layer. The drag coefficient for a bullet slug shaped object (both ends) in this type of flow is around 0.3 (in contrast, an extremely aerodynamic airfoil at zero angle of attack has a drag coefficient of around 0.045). If the object is made narrower (more cigar-shaped), the drag coefficient decreases significantly.

[0057] Again, assuming a diameter of 300 feet (or radius of 45.72 meters) with a double bullet shape, the cross-sectional area is about 6,467 sq. meters. 100 MPH is 45 meters/second. Using the density of air at 39,000 feet from the standard atmosphere of 0.316406 kg/cu meter, the drag force is 622,860 Newtons, or 140,024 lbs. This thrust could be supplied by several conventional jet engines.

[0058] Much higher speeds can be attained with a cigar-shaped craft. Consider again for example a cigar-shaped craft of 100 feet in diameter with a friction coefficient of 0.17. In this case, the thrust required to maintain 350 MPH is 108,000 lbs. This could be supplied by several conventional jet engines. A craft 100 feet in diameter with a length of 4000 feet configured as a cylinder totally filed with hydrogen could lift 2,226,232 lbs. at sea level and 444,269 lbs at 39,000 feet. Thus, in this example, a speed of 350 MPH is attained at altitude while still lifting 222 tons of total weight to that altitude. A pointed or needle nose and tail would add further to the aerodynamic efficiency.

[0059] The above-discussed examples clearly show the feasibility of constructing a hydrogen carrying craft that could lift 100 tons to 39,000 feet and maintain 300 MPH at that altitude with only two engines. The examples show an abundant lift capacity to lift the weight of the engines and payload as well as the structural weight of the proposed craft.

[0060] As stated, in the preferred embodiment of the present invention, the engines in the preferred embodiment burn hydrogen (perhaps from a tank of highly compressed or liquefied gas). The engines can also run on non-conventional fuel such as hydrozine. Such engines are generally much lighter than a conventional jet engine and will provide adequate thrust for the craft of the present invention. Total drag can be minimized by reducing the diameter of the craft, using a pointed nose and possibly tail. The payload carrying capability can then be increased by lengthening the craft. The craft can thus be lengthened (within the bounds of structural stability) to tradeoff payload carrying capacity against engine and possibly fuel weight.

[0061] Although, as mentioned above, all of the features of the system are not required in order to practice the principles of the invention and thus some are optional. It is deemed apparent that each of the features illustrated in the accompanying drawings and the foregoing description are attractive and add to the usefulness of the invention. Additionally, although the disclosure hereof has been stated by way of example of preferred embodiments, it will be evident that other changes and modifications may be employed without departing from the spirit and scope thereof. Each of these changes or modifications is within the scope of the present invention. The terms and expressions employed herein have been used as terms of description and not of limitation; and thus, there is no intent of excluding equivalents, but on the contrary it is intended to cover any and all equivalents that may be employed without departing from the spirit and scope of this disclosure.