DE3002828A1 - Solar airship using heat-absorbing inflated body - having transparent and dark foils on top and sides - Google Patents

Abstract

The airship has one or more bodies enclosed by a thin lightweight foil converting direct and diffuse solar radiation, into heat, the warm air used to provide lift. The foil forming the top of each body is transparent, while that forming its underneath is dark. The body is altered in inclination angle and by incorporating controlled apertures the air inside it can be changed with that on the outside, thus allowing full manoeuvrebility in all three coordinate planes. Propulsion is provided by electromotively driven propellers using power from solar cells.

Description

Solar airship

The age of aviation began with the invention 200 years ago of the hot air balloon by the Montgolfieres brothers. Since then, the flight technology experienced a great boom and there were light gas balloons, airships, by Fixed-wing and swivel-wing aircraft powered by propellers, nozzles or rockets were developed.

All these aircraft have in common that they either have a high Energy requirements for their propulsion or need flammable or expensive buoyancy gases.

Despite the advantages of these devices, this leads to a high level of specificity Transport costs and, in most cases, pollution from exhaust gases and Noise.

At a time of growing energy shortage and growing With a sense of the primeval world, it makes sense to look for alternative energy sources for aircraft to search.

The present invention therefore relates to an airship which is in Essentially, solar energy is used as lift and propulsion energy.

According to the invention, the direct and diffuse incident solar energy is intended for this purpose absorbed inside a body wrapped in light and thin foils - and be converted into heat. The warm air produced in this way works in the same way as classic hot air balloon static buoyancy of the body in the surrounding area denser air.

The body floats when its weight including the shell is the same weighs like the volume of air it displaces, it rises when its weight is less.

The lift force A is calculated as follows: A = V - O 6 d (A = lift force, = 2 X = air density outside ... air density inside, 0 = surface of the body, = specific Weight of the body shell, d = thickness of the shell, V = volume of air enclosed in the body).

Since the air density k is a function of the temperature T (t T)) must For a given weight of the body shell, the interior air has a predetermined minimum temperature increase compared to the ambient air. The larger the volume of the float, the more favorable are the ratios, since the volume with the third power, however, the surface only grows to the power of the second of the diameter.

According to the invention, the tread body should be transparent on its upper side for sunlight, but if possible black or reflective for infrared radiation > 3 gm and have good thermal insulation properties. The lower one The side of the float is absorbent on the inside and black on the outside designed to be insulating against heat conduction and radiation.

The air inside the float heats up in the area of the radiation-absorbing floor and rises through convection to the top. The equilibrium temperature is reached when the heat loss through the surface of the float corresponds to the absorbed solar energy.

At full solar irradiation of approx. 1 kW / m2 are described in the Buoyancy bodies in the case of covering with only a thin film increase in temperature compared to the ambient air of approx. 35 K, with a double skin covering of approx. 70 K reached.

In the first case, this corresponds to a buoyancy force / m3 of approx. 140 p, in the second case 240 p.

According to the invention, the shape of the float is chosen so that with the largest possible volume of air resistance (shape, friction and induced drag) in the horizontal position is as small as possible compared to that in the vertical position.

A buoyancy body which is optimized in shape in this way is inventively used for example by an ellipsoid or. Double ellipsoid formed. (Fig. 1) (1,1). Other forms such as B. Double spherical caps (1,2) cylinders (1,3) cylinder packings (1.4) Packings of balls of different sizes (1.5) and the like are possible.

According to the invention, the payload is displaceable below the buoyancy body attached and thus allows a positive or negative setting angle of the whole Buoyancy body.

In this way, according to the invention, part of the solar radiation generated static buoyancy can be converted into dynamic propulsion.

The described 'arrangement' thus represents a solar airship, which allows to fly from a point A on the earth's surface to a point B.

Fig. 2 illustrates these basic inventions. In state A, the solar airship is with the air resistance ratio perpendicular = n on the floor. The useful horizontal load is hung so that the Buoyancy body has a positive angle of attack. That absorbed in the dark ground Solar energy heats the air inside the body until it rises and a rate of climb Vst determined by the wing loading is reached (State C). The airspeed is then VF1 = V5t * n. Since with increasing Altitude the air density te decreases, the airship increases with decreasing rate of climb maximum up to the equilibrium height. Before reaching this height is done by draining of hot air reduces the load-bearing capacity of the buoyant body to such an extent that the static Lift is less than the flight weight. This point (state D) represents simultaneously the upper turning point from the positive to the negative angle of attack, through load shifting, Thereupon a flat glide occurs (state E), which up to lower turning point (state F) results in which the air inside the ship turns is heated, and then the climbing state C is reached again.

The described oscillating vertical movement is continued as long as until the desired landing point B is reached.

Like the direction of flight, according to the invention, lateral Course deviations can be achieved by shifting the load accordingly.

Fig. 3 shows the basic embodiment of the invention Solar airship as it is mainly suitable as sports and leisure equipment. Included 1 is the transparent epidermis, 2 the black subcutaneous tissue, 3 an ellipsoid sector, 4 a light structured ring, 5 the solar radiation, 6 the adjustable via rollers Suspension ropes of the pilot's seat, 7 the pilot on his in the longitudinal and transverse directions seat movable by cable pull, 8 the air release cap, 9 the operating rope belonging to 8, 10 the lower air inlet opening.

According to the invention, both the described change in the angle of attack as well as the lateral course deviations instead of by shifting weight corresponding slight elevator and rudder can be achieved. (Fig. 4) The following mean: 11 elevator, 12 elevator control cables, 13 rudder, 14 rudder control cables.

Another inventive variant of the solar airship is thereby given that the propulsive power and the residual buoyancy by pivoting propellers is produced. The drive of this propeller can be done with thermodynamic machines or with electric motors.

In the former, the required process heat can according to the invention by means of optical lightweight concentrators are produced, which either additionally on or are installed in the float, or through a mirrored part of the float are self-generated.

Fig. 5 shows the schematic structure of a solar airship with adjustable propellers (15), lightweight solar concentrators (16), process steam generators (17) and heat engine.

Fig. 6 shows the schematic structure of a solar airship in which the concentrator has an internally mirrored spherical cap-shaped bulge (19) is formed in the bottom of the airship. The steam generator (19) is the wandering Focal point tracked.

When the propellers are driven by electric motors, it is advisable to the required electrical energy by means of solar cells on the bottom of the float to create. Very light solar cells, especially made using the thin-film process could generate electricity and heat (due to their relatively dark color) well combine with each other.

The versions sketched in Figures 4 and especially 5, 6, and 7 of the solar airship according to the invention are due to weight reasons and due to physical boundary conditions only make economic sense in relatively large dimensions possible.

However, that which increases with the third power has a positive effect Volume out. For example, while a solar airship of the embodiment Fig. 2 can transport approx. 250 kg payload with a diameter of 20 m, such a with a diameter of 100 m already carry approx. 50,000 kg payload.

Another inventive variant of the solar airship described is sketched in Fig. 7. A very large solar float (21) is transported in this case a large load (22) and is towed by a tractor on the ground (23). The tow rope (24) is used; at the same time to operate the airship control organs.

This embodiment is particularly good as a cargo ship for remote, sunny areas such as B. the Sahara suitable.

Correspondingly large-sized solar airships of the ones described Construction can be dimensioned in a further embodiment according to the invention that their equilibrium altitude lies in the ftcatosphere and they because of their thermal insulation and its flat angle of slide above it even during the night stay in the troposphere. According to the invention, you thus provide retrievable, steerable Stratospheric satellites.

The present invention replaces the fossil fuel energy of the Montgolfiere through solar energy and complements this measure with an aerodynamic design of the float.

The result is a completely new solar airship that comes in different Versions from simple sports equipment to cargo trucks and stratospheric satellites can be executed.

The main areas of application for solar airships will be the sunny ones Be developing countries of the earth.

From a technological point of view, the elements of lightweight construction can be larger Structures such as B. in the Zeppelin and in the "textile architecture" used come, should in principle be seen as resolved.

In terms of material, it is primarily the transparent cover of the float that is used because of the strong U.V. Load problematic. According to the invention, high-quality Fluorocarbon films, especially tetrafluoroethylene, which is excellent has optical, thermal and mechanical properties, are used.

Claims (1)

Patent claims 1 Solar airship D a d u r c h e k e n n z e 1 c h n e that the over a transparent foil inside one of light foils encased propulsion body direct and diffuse solar radiation reaching into the dark floor membrane is absorbed and generates warm air that is except for a static Buoyancy also generates a dynamic propulsion of the buoyancy body, as this Is formmäflig optimized so that it is horizontal with the largest possible interior Has a smaller air resistance in the direction than in the vertical direction and aie payload is slidably mounted so that the buoyancy body has a positive or negative angle of attack can be imparted and this, in connection with flap opening to completely or partially replace the airship interior air with AuXenlutt full maneuverability in the three coordinates of the air rate. 2.) Solar airship according to claim 1 d a d u r c h g e k e n nz e i c h n e t that the shape of the buoyancy body is that of an ellipsoid or double ellipsoid is. 3.) Sqlar airship according to claim 1 d a d u r c h g e k e n nz e i c h n e t that the shape of the airship consists of a double spherical cap. 4.) Solar lutohiff according to claims, 2, 3 d a d u r c h g e -k e n Not that the shape of the airship differs by a dense packing large spherical balloons which are covered by an additional outer skin, is formed, 5.) Solar airship according to claim 1 d a d u r c h g e-k e n nz e i c h n e t that the shape of the airship by a cylinder or a parallel pack of cylinders is given. 6.) Solar airship according to claims 5 d a d u -r c h g e -k e n nz e i n e t that the buoyancy and propulsion, or parts of the buoyancy and Propulsion can be accomplished by swiveling, motor-driven propellers. 7.) Solar airship according to claim 6 d a you r c h g e k e n nz e i c h n e t that the drive motors of the propellers are electric motors and their energy obtained from thin-film solar cells on the dark floor of the airship. 8.) Solar airship according to claim 6 d a d u r c h g e k e n nz e i c h n e t that the drive motors are thermodynamic machines and their process heat from lightweight solar concentrators either attached to the airship are, or consist of parts of the airship. 9.) Solar airship according to claim 8 d a d u r c h g e k e n nz e i c h n e t that the integrated solar concentrator consists of a spherical cap-shaped, mirrored bulge in the bottom of the airship consists - and the absorber dem Focus is tracked. 10.) Solar airship according to claim 6 d a d u r c h g e k e n nz e i c h n e t that the propeller is powered by an internal combustion engine is produced. 11.) Solar airship according to claims 1 - 10 d a d u r c h g ek e n It does not point out that part of the energy is used to heat the air - through combustion an carried fuel is generated. 12.) Solar airship according to claim 1 because d u-r c h g e k e n nz e i c-h n e t that the vertical and horizontal changes in attitude are due to slight Elevator and rudder are accomplished. 13.) Solar airship according to claims 1 - 12 d a d u r c h g ek e n Not that the size is tailored to the transport of a person and the device is used as sports equipment. 14.) Solar airship according to claims 1 - 12 d a d u r c h g ek- e It is not noted that its size and shape is such that it can be transported larger loads is possible. 15.) Solar airship according to claims 1 - 12 d a d u r c h g ek e n-n notices that a large load-lifting body is carried by a moving body on the ground The tractor is towed and the tow rope in addition to operating the controls of the float is used. 16.) Solar airship according to claims 1-15 d a d u r c h g ek e n It does not indicate that the desired shape of the buoyancy body can be achieved by a combination lighter structure rings and appropriately cut foil sectors is produced. 17.) Solar airship according to claim 16 d a d u r c h g e k e n nz e i c h n e t that the structural rings consist of aluminum tubes that can be plugged together be inserted through the outer mounting tabs of the film body. 18.) Solar airship according to claim 16 d a d u r c h g e k e n nz e i n e t that the structural rings are pneumatically inflatable tubes that are used in the foil skin of the float is integrated at a suitable point. 19.) Solar airship according to claim 1 d a d u r c h g e k e n n z e i c h n e t that both the shell and the pneumatic structural ring are made strong made of stretchable elastic material, so that a greater volume expansion without Gas exchange becomes possible. The volume, which changes with the height, therefore remains the lift almost constant with increasing airspeed. 20.) Solar airship according to claim 19 d a d u r c h g e k e n n z e i c h n e t that only the pneumatic structural ring is full of air, while the thickness of the esthOlle is reduced at greater heights by releasing gas will, waa improved the aerodynamic properties of the airship. 21.) Solar airship according to claim 1 d a d u r c h g e k e n n z e i c h n e t that the absorber foil is stretched conically in the interior of the buoyancy body gates is and is provided with openings on its periphery in such a way that the chimney effect a strong tension develops that distributes the warm air. 22.) Solar airship according to claim 1 d a d u r c h g e k e n n z e i c h n e t that the float is inflated by means of a fan on the ground This fan also provides an overpressure that is independent of the height receives.