METHOD FOR AIR-DRIVEN PROPULSION OF A VESSEL AND AIR-DRIVEN VESSEL
The present invention relates to a method for air-driven propulsion of a vessel, according to the prea mble of claim 1.
The present invention also relates to an air-driven vessel, according to claim 5. Background
There is an increasing focus on energy effective vessels and propulsion systems. There is a major focus on hybrid and electrical propulsion systems, and design of energy favorable hulls for vessels. There exist hovercrafts utilizing air for moving the vessel a bove the surface the vessel is moving on.
The principle of hovercrafts is per time not transferred to more traditional vessels, something the present invention seeks to present. Object
The main object of the present invention is to provide an air-driven vessel and a method which utilizes pressurized air for propulsion of the vessel.
It is further an object of the present invention to provide a n air-driven vessel and a method which utilizes pressurized air for providing minimal friction between hull of the vessel and surface of sea .
The invention
A method for air-driven propulsion of a vessel is described in claim 1. Preferable features of the method are described in the claims 2-4.
An air-driven vessel is described in claim 5. Preferable features of the vessel are described in the claims 6-23.
The present invention is based on utilizing pressurized air for propulsion of a vessel. The idea is based on collecting air above the surface of the sea and pressurizing this by means of suitable means, and further by means of suitable means using this pressurized air for propulsion of the vessel.
This pressurized air is preferably conveyed from upper part of the vessel to lower part of the vessel, i.e. lower part of hull of the vessel, preferably firstly to front part of the hull, where the pressurized air is blown out via one or more openings positioned under the sea surface, i.e. in opposite direction of moving direction of the vessel, for therethrough to move the vessel forward.
The same air which is utilized for propulsion of the vessel will further rise up again from the water and by means of arrangement of means for catching this air it can be provided an air cushion between the hull of the vessel and the sea which reduces friction.
The present invention is preferably further arranged for reuse of the air which is trapped under the hull by conveying it from the air space under the hull and blowing it out again in the same way as described above at rear end of the hull.
For making the propulsion even more effective the present invention can include pulsation devices, which are arranged for pulsing the air which is used for propulsion.
For making the present invention even more energy effective it includes means for minimizing friction between the hull of the vessel and the sea. This can be achieved by that excess air from the air cushion provided under the hull is caught and let out again at sides of the hull, and at the bow.
Further preferable features and details of the present invention will appear from the following example description.
Example
The present invention will below be described in more detail with references to the attached drawings, where:
Figure 1 is a principle drawing of a first embodiment of the present invention,
Figure 2 is a principle drawing of means for catching air at rear end of the hull of the vessel, Figure 3 show different cross-sectional views of a vessel,
Figures 4A-G show a first embodiment of a device for improving the efficiency of the propulsion of the vessel,
Figures 5A-B show a second embodiment of a device for improving the efficiency of the propulsion of the vessel,
Figures 6A-F show principle drawings of a hull for minimizing the friction between the hull and the sea according to the present invention,
Figure 7 shows an alternative embodiment for supplying air to air channels, and
Figures 8A-B show principle drawings of alternative embodiments for opening and closing air openings in air channels.
Reference is first made to Figure 1 showing a principle drawing of a first embodiment for air- driven propulsion of a vessel 100 of the present invention. The present invention is especially directed to a vessel 100 having a hull structure which corresponds to a multi-hull vessel, such as catamaran, trimaran, etc. Hull parts 101 of the vessel preferably exhibit an open channel 102 at
their lower end which is open against the sea, as e.g. shown in Figure 6E. The idea is based on collecting air at upper part of the vessel, pressurizing this air and utilizing it as propulsion by blowing this air out in the channel 102 of the hull parts which is open against the sea. This is achieved by that the air-driven vessel is provided with air inlet 11 arranged in a fan room 12 which collects air, which air further is pressurized/compressed by means of one or more powerful motors or air compressors (fans) 13. The pressurized air is next conveyed by means of one or more air channels or ducts 14 extending from the fan room 12 and down to the open channel 102 of the hull parts ending in an opening 15 where air is blown out under the sea surface 150 for providing propulsion of the vessel. The opening 15 is preferably arranged in approximately horizontal position in the longitudinal direction of the vessel, i.e. in opposite direction of the moving direction and thus moves the vessel forwards. E.g. it can be arranged nozzles at the ends 15 of the duct 14, or the air can be blown directly out.
This air will not only work as propulsion, but the air will also rise up again from the sea under the hull, and by capturing this air by means of a hull construction 20, arranged under the hull, one will be able to provide an air cushion under the hull which reduces the friction between the hull of the vessel and the sea, something which is called air lubrication. In this way the present invention provides energy effective propulsion of the vessel due to that the same air is used both as propulsion and for reducing friction.
The captured compressed air can also be reused and utilized for further propulsion of the vessel, which will be further described below. This can be achieved by that the vessel is provided with a hull construction 20 as shown in Figure 2. The hull construction 20 is as mentioned arranged for capturing the compressed air which is under the hull. The hull construction 20 includes for this one or more sealing means 21 for capturing the air under the hull and preventing it from escaping, e.g. to the side of the hull. The sealing means 21 are e.g. formed by rubber sleeves which by means of controllable means, such as piston/cylinder units, wire or similar 22, where these can be hydraulically or electrically/mechanically driven, for moving the sealing means 21 up towards or away from the hull of the vessel. In this way one can capture air present under the hull of the vessel such that it provides an air cushion under the hull. The same air can be conveyed further into one or more air channels or ducts 23 leading from an air space 24 created under the hull to the rear end of the hull, i.e. in front of the hull construction 20, and ends in an opening 25 in the open channel 102 of the hull parts, where the air is blown out below the sea surface 150 for providing the vessel with further propulsion. The opening 25 is preferably arranged in
approximately horizontal position in the longitudinal direction of the vessel, i.e. in opposite direction of the moving direction and thus moving the vessel forwards. In the same way as above, the end of the duct 23 can be provided with nozzles or blowing the air out directly.
Accordingly, it is provided an air-driven vessel which firstly is using pressurized air for propulsion if the vessel, which air further rises up from the sea and provides an air cushion under the hull, which air again is reused for providing further propulsion.
One can further adapt the air space wall plate construction with a bow shape so that occurring adjustments of the hull construction 20 upwards or downwards do not result in wear and tear in the sealing means 21. The hull construction 20 can be controlled so that it with necessary force captures as much air as possible under the hull, and at the same time avoids resistance for propulsion of the vessel.
Reference is now made to Figure 3 which shows a cross-sectional view of the vessel 100 according to the invention. The chassis or hull of the vessel can, according to the invention, be designed as a U-shape turned upside down or with different U-cross-section views as shown in Figure 3 by 30A, 30B, 30C, 30D, 30E and 30F, and similar, and combinations which can capture air in an air space 24 between the bottom of the hull and the sea. By means of the rear bow construction 20, a closed void is formed; limited by the hull parts and the sea surface, and the air inside this void will contributes to so-called air lubrication, something which greatly reduces the frictional resistance for the propulsion of the vessel in the sea.
Reference is now made to the Figures 4A-E showing a first embodiment of a device for improving the efficiency of the propulsion of the vessel 100. The device is arranged for pulsing and pumping the air backwards and into the sea as a jet motor.
The device is arranged for arrangement in the ducts 14 and alternatively 23, preferably at the ends 15 and 25, respectively, of the ducts 14, 23, but can also be arranged further into the ducts 14, 23. The device is based on a valve principle which opens and closes for the air which is let out of the ducts 14, 23 and therethrough provides a kind of pulsation which provides increased effect for the propulsion.
According to the first embodiment of this device it includes a first plate 40 (shown in detail in Figure 4B), which plate 40 is fixed in the duct 14, 23 and is provided with a number of holes 41 for letting air through, which plate 40 is arranged close to the opening 15, 25 of the ducts 14, 23. It further includes an opening and closing device 42 (shown in detail in Figure 4C), arranged inside the plate 40 (seen from the end 15, 25 of the duct 14, 23), which opening and closing device 42 is arranged with the same axis 43 as the first plate, and is provided with arms 44 and plates 45 adapted the holes 41, so that by rotation of the opening and closing device 42 it will open and close all the holes 41, alternating. The device further includes a plate 46 arranged inside the opening and closing device 42, as shown in Figure 4D, which plate 46 can have any shape so that it does not close the air passage out of the duct 14, 23. The plate 46 is preferably fixed to the duct 14, 23 or the plate 40 and is preferably shaped as a hemisphere, and provided with openings/cuts
47 around the periphery which allows air to flow through and the plate 46 will contribute to improved pulsation force. The plate 46 will have the function that it ensures effective blowout due to the air on the way out is pushed by a hard base.
Accordingly, the rotation of the opening and closing device 42 will open and close the air passage through the duct 14, 23 and provide pressure increase at the backside of the device when the opening and closing device 42 is closing the holes 41 and a following expelling air pulse and jetlike force which provides improved effect of the propulsion of the vessel 100 in the sea when the opening and closing device 42 opens for the holes 41.
Rotation of the opening and closing device 42 can be performed by means of a motor 50 arranged for controlling the pulsation frequency, as shown in Figure 4E, alternatively as shown in Figures 4F-G. In Figures 4F-G it is shown a solution where the opening and closing device 42 is driven by means of the air in the air channel 14, 23. In Figure 4F it is shown a curved duct 51 arranged between two circular plates which by means of air supply from the inside of the air outlet 52 in Figure 4G, can rotate and at the same time rotate the opening and closing device 42 with it, which in turn opens and closes the holes 41, which results in that a pressurized air pulsation. A controllable closing valve 53 is preferably arranged for adjusting the air amount and pulsation frequency, as shown in Figure 4G.
As shown in Figure 4C the opening and closing device 42 preferably includes a ring 48 provided with small balls 49, see Figure 5B, working as a ball-bearing, arranged under the ring 48, resulting in that the opening and closing device can rotate or pivot steady with minimal distance from the base, so that the disc 45 of the opening and closing device 42 entirely or partly can close the air passage through the holes 41 of the plate 40.
Reference is now made to Figures 5A-B which show a second embodiment of a device for enhancing efficiency of the propulsion of the vessel 100. According to the second embodiment it includes a cylindrical body 70 provided with holes 71 which can be arranged in the ducts 14, 23. A rotating opening and closing device 72 provided with arms 73 and plates 74 adapted to the holes 71 is arranged inside the cylindrical body 70, which opening and closing device 72 is arranged for rotating in relation to the cylindrical body 70, and the plates 74 will alternatingly open and close the holes 71, and therethrough the above mentioned pulsating air force is achieved. The opening and closing device 72 can be driven in the same way as described for the opening and closing device 42. This alternative can also be modified so that the opening and closing device 72 is arranged on the outside of the cylindrical body 70 and is closing the holes 71 from the outside.
One can also arrange one or more ducts 60 with valves which extending to the atmosphere, see Figure 1, in the air space 24, so that one can empty the air space 24 in desired cases.
Above is described how one can move vessel forward by means of pressurized air at the front of the vessel, and capture air rising up again from the sea to form an air cushion under the vessel.
It is further described that the captured air can be utilized for providing further propulsion at the rear end of the vessel for therethrough to achieve higher propulsion force.
The present invention is best suited for a multi-hull vessel, such as a catamaran, trimaran or similar, seen from behind, i.e. the hull exhibits several hull parts 101 having side walls 111, 112 which are in the sea and the vessel is supported on.
Below will be described how one can reduce friction between the hull parts which are in contact with the sea.
The solution is as above to provide an air cushion between the hull parts 101 and the sea.
Reference is now made to Figures 6A-F showing principle drawings of a hull of a vessel 100 according to the present invention. The figures show how one utilize air rising up under the hull of the vessel to provide an air cushion between the hull of the vessel and sea, and similarly in the outer 111 and inner 112 walls of the hull parts 101, as shown in Figure 6C-F.
As mentioned and described above, air which is used for propulsion of the vessel will rise up again from the sea under the vessel and be captured under the hull due to the hull construction 20. According to the invention this air is utilized to reduce friction between the hull and the sea by providing an air cushion between the hull parts 101 and the sea, and between the bow and sea. For achieving this the walls 111, 112 of the hull parts 101 are provided with air openings 113 which will convey compressed air from the air space 24 under the vessel into a limited part 114 of the hull parts 101 over the open channel 102, between the walls 111, 112, as shown in Figure 6C.The air will further be conveyed out in the open channels 102 of the hull parts against the sea through openings 115 arranged between the limited part(s) 114 of the open channel 102 of the hull parts 101, as shown in Figure 6D.
In the open channels 102 is further arranged covers 116, as shown in Figure 6D, arranged to the openings 115 for guiding air which is conveyed through the openings 115 backwards along the entire vessel, as shown in Figure 6D.
In other words, when the air space 24 under the hull is filled with air as a result of the propulsion means described in Figures 1-5 and is rising again from the sea and captured by the hull construction 20, air will flow from the air space 24 and into the limited parts 114 of the hull parts
101 and filling them as a consequence of pressure from the vessel against the sea. This further results in that the air by means of the openings 115 and covers 116 are filling the open channels
102 with air and the excess air will flow out from the sides as shown in Figures 6A, 6C, 6D and 6E and thus provide an air cushion between the hull parts 101 and sea. Figure 6D is incidentally a
transparent illustration so that the open channels 102 and covers 116 in the practical design are not visible from the outside.
The open channels 102 of the hull parts 102 extend preferably the entire length along the lower part of the hull, preferably around the entire vessel and ensure that the vessel is encircled by an air cushion reducing the friction between the hull and sea water when the vessel is sailing and moving.
The open channels 102 can further preferably be closed at the rear end of the vessel, i.e. at the very rear end of the vessel.
As regards the bow of the vessel which first is in contact with the sea, it needs more air, something which is solved by arranging a mainly vertically extending air channel 117, which extends from below and up along the bow and follows the bow a distance under the water surface, as shown in Figures 6A and 6B, so that air is blown vertically down or up for providing an air cushion between the sea and the bow for reducing the resistance from the sea water.
In this case one can arrange air valves 118 up on the bow which can be closed if necessary. In other words, the figures show how air flows into the limited parts 114 of the hull parts 101 through openings 115 along the entire hull, at both sides, and which is conveyed out in the open channels 102 of the hull parts through the openings 115 and covers 116, and which is further forced out from the open channels 102 and rising along the sides 120A-B of the walls 111, 112, inside and outside, for therethrough to provide an air cushion between the sea and the hull of the vessel.
For controlling this function it is preferably arranged a closing device 130, as shown in Figure 6F, in the form of a closing disc provided with openings 131 which is arranged over the openings 115, i.e. in the limited parts 114 of the hull parts 101. In this way one can by adjusting the closing device 130 adjust the air flow to the open channels 102 between entirely open, entire closed or a position between.
Reference is now made to Figure 7 which utilize springs 140, 141 arranged to one or more closing valves 142 arranged in a mounting point 143, either by use of one of the springs 140, 141 or by use of both, as an alternative to the prior shown embodiments, for controlling the outlet of air from the open channels 102 and possibly the vertical air channel 117. When one shall supply air for providing the air cushion around side walls positioned in the sea, the pressurized air from the means 13 will open the closing valve 142 to an open position 143 by means of the air pressure and thus let air out. When the pressure is removed the spring 140, alternatively the springs 140 and 141, will move the closing valve 142 to closed position again. The pressure from the sea water itself will also contribute to moving the closing valve 142 to closing position again.
In another embodiment the closing valve 142 is arranged to open and close for air to both the open channels 102 and the vertical air channel 117. If necessary it can be arranged a separate spring for opening and closing for air in the air channel 117.
In a further embodiment the springs 140, 141 are obeyed so that it is only the pressure from the sea water which moves the closing valve 142 back to closed position.
Reference is now made to Figures 8A-8B which show principle drawings of alternative embodiments for opening and closing of air openings 113 in the open air channels 102. According to this embodiment it is arranged means 150 for opening and closing the openings 113 which lead into the open air channels 102. The means 150 is e.g. formed by a closing disc 151 provided with openings 152, which closing disc 151 extends in longitudinal direction of the hull parts 101 and is movably arranged to the hull parts 101 by means of suitable fastening means 153, such as angle sections, for movement over the openings 113. The closing disc 151 is further provided with power means 160 which are arranged for moving the closing disc 151 forwards and backwards for therethrough to move the openings 152 over the openings 113 for opening and closing the openings 113 by moving the closing disc 151 so that the openings 152 do not cover the openings 113. E.g. the power means 160 can be a motor (not shown) provided with a shaft 161 having toothed wheels 162 co-operating with an area 163 provided with teeth on the closing disc 151. In this way one can open and close the air supply from the air space under the vessel to the air openings 113.
Modifications
In connection with long vessels it can preferably be arranged several re-use blow-outs in the longitudinal direction of the vessel. E.g. it can be arranged several hull constructions 20 capturing air at several places and which blows it out again 25.
The air-driven vessel can include several air inlets and several motors or pressure pumps (fans) for providing sufficient air amount for propulsion.
The air-driven vessel can further include separate air inlets, motors or pressure pumps (fans) for providing an air cushion around the hull of the vessel.