Watercraft

Abstract

Method and watercraft (1), in particular a glider, comprising: a hull (2), a main drive (1A), preferably an electric drive, in particular at least one rear electric motor, an air nozzle unit (3) with a compressor (4), in particular with a radial compressor, for generating an air flow, with an air supply line (12) carrying the air flow, and with an air nozzle (5) connected to the compressor (4) via the air supply line (12) for applying the air flow to the outside of the hull (2), that a flat nozzle (6A) is provided as the air nozzle (5), which extends outwards, preferably also rearwards, from a central region of the hull (2), viewed in plan view, that the flat nozzle (6A) has an elongated air outlet gap (9) at the rear end for the outlet of the air flow, and that the flat nozzle has a water separation edge (12) at the rear end,so that behind the elongated air outlet gap (9) of the flat nozzle (6A) an air film can be formed along the outside of the fuselage (2).

Description

[0001] The invention relates to a watercraft, in particular a glider, comprising: a fuselage, a main drive, preferably an electric drive, in particular at least one electric rear motor, an air nozzle unit with a compressor, in particular with a radial compressor, for generating an air flow, with an air supply line carrying the air flow and with an air nozzle connected to the compressor via the air supply line for applying the air flow to the outside of the fuselage.

[0002] Furthermore, the invention relates to a method for moving a watercraft, in particular in planing mode, on a body of water.

[0003] Watercraft, especially boats, come in two distinct types that differ significantly in terms of their design, operation, and intended uses. Displacement boats are designed to displace water as they move through the water. This means that displacement boats submerge in the water and push some of the water sideways to propel themselves forward. Displacement boats have a hull that usually has a distinctive hull shape with a V-shaped hull. This hull shape provides stability and good seakeeping; however, the maximum speed of displacement boats is limited to the hull speed. Displacement boats are used for things like cruise ships, cargo ships, and sailboats where speed is not a critical factor.In contrast, planing boats are designed to glide on the water as they gain speed, rather than displacing it. Planing boats achieve higher speeds by gliding on the surface of the water, rather than submerging it. The hull of planing boats often has a flat shape, allowing them to use hydrodynamic drag to lift themselves off the water and plane on the surface. Planing boats are generally lighter and have a shallower draft than displacement boats, which increases their speed and maneuverability. Planing boats are often found on pleasure craft and fast workboats, such as those used by the Coast Guard.

[0004] Plane boats consume a lot of energy because, due to their special design and higher speed, they require more power to glide across the water's surface. The energy required increases exponentially with increasing speed, requiring powerful motors to power these boats. This has made the use of electric motors in planing boats less practical to date, as the energy density of the energy storage for the electric motor is too low to allow the planing boat to operate for extended periods.

[0005] In the state of the art, various attempts have also been made to reduce the hull friction of watercraft, since it has already been recognized that at higher speeds, hull friction accounts for the majority of the propulsion power, whereas water displacement at planing speed only accounts for a fraction of the propulsion power.

[0006] EP 2 123 551 A1 describes a method for reducing frictional resistance between a ship's hull and the water by releasing gases. For this purpose, a plurality of gas outlets are arranged on the hull. In one embodiment, the gas outlets are arranged laterally along a keel line 301. Furthermore, an embodiment of a ship with a flat hull bottom is described. One embodiment using a pipe system can also be retrofitted, i.e., installed on ships that are already in operation. In another embodiment, several gas outlets are already included during ship manufacture and are thus integrated into the hull. A supply chamber pressurizes air / gas (ambient air or exhaust gases) or a mixture of air and gas in order to transport it via pipes to the gas outlets.Before the gas exits the outlets, it can be "vaporized" by a heating device, causing the resulting air bubbles to rise along the hull and along a flow line. The heating device is located on the perimeter of each gas outlet. If turbulent flows develop due to the ship's higher speeds, high- and low-pressure areas could develop along the hull, creating very high frictional resistance. To counteract this phenomenon, the amount of gas released at the outlet openings can be controlled. For example, more gas could be released in certain sections to specifically counteract high- or low-pressure areas a and b. This effect is described for 10 knots (~18.5 km / h) and 15 knots (~27.7 km / h).

[0007] However, this known design only achieves a slight reduction in friction. Although the gas discharge causes air bubbles to rise along the boat's hull, hull friction still increases rapidly at high speeds.

[0008] Other designs with air discharge onto a boat hull are described in DE 10 2017 101 055 A1, GB 2508027 A and CN 102897282 A.

[0009] The object of the invention is therefore to alleviate or eliminate at least some of the disadvantages of the invention. This object is achieved by a watercraft according to claim 1 and a method according to claim 11. Preferred embodiments are specified in the dependent claims.

[0010] According to the invention, a flat nozzle is provided as the air nozzle, which is arranged flat against the underside of the fuselage. The flat nozzle extends, in plan view, from a central region of the fuselage outwards, in particular to one of the two outer regions of the fuselage, and preferably also to the rear. The flat nozzle has an elongated air outlet gap at the rear end for the outlet of the flow of compressed air, hereinafter referred to as the air flow, which is guided from the compressor via the air supply line to the flat nozzle. In addition, the flat nozzle has a water separation edge at the rear end, which is designed so that an air film can be formed along the outside of the fuselage behind the elongated air outlet gap of the flat nozzle.

[0011] Advantageously, by reducing the hull friction of the watercraft, the energy requirement per mile can be significantly reduced. The faster the watercraft is moved through the water, the more advantages arise from the air nozzle unit according to the invention. The watercraft is preferably a planing vessel, in particular a planing boat, preferably a sports or work boat, for example for a coast guard. Due to their use, such watercraft are operated at planing speed for a large part of their travel time. According to the invention, an air film is created between the water and the hull. For this purpose, the air nozzle unit has an external energy source in the form of the compressor in order to achieve the required air pressure and the associated flow rate. In a preferred embodiment, the air pressure is generated by a radial compressor.With the help of this pressure generation, an air flow, preferably with a defined pressure difference and consequently air outlet quantity, can now be discharged from the flat nozzle and guided along the fuselage.

[0012] To form the air film on the underside of the fuselage, the flat nozzle has an elongated air outlet gap whose centerline preferably runs substantially parallel to the adjacent section of the fuselage. The length of the air outlet gap is several times greater, preferably at least 5 times, more preferably at least 10 times or at least 50 times, in particular at least 100 times or at least 200 times, than the height of the air outlet gap perpendicular to the outside of the fuselage.

[0013] In order to distribute the air evenly along the underside of the hull that comes into contact with the water, the air outlet gap is located at the rear of the flat nozzle, which also has a water separation edge in the rear area, so that the flat nozzle is designed as a disruptive body. At the water separation edge, the water film is lifted off the watercraft, so that a hollow space is created behind the flat nozzle, viewed in the direction of movement of the boat, which is kept clear by the air flow. The flat nozzle preferably covers an imaginary hull line that is still below the waterline when planing, in particular 50mm to 200mm, for example 150mm, below the waterline. Starting from the central area of ​​the hull, in particular from the keel area of ​​the hull, the air behind the flat nozzle is distributed outwards in line with the planing surface of the watercraft.Advantageously, the air nozzle unit according to the invention can create a stable layer of air beneath the fuselage, which results in a significantly greater reduction in friction than the prior art described above. Advantageously, this effect becomes even more pronounced with increasing speed. Example:

[0014] By lifting the boat's hull off the water film, friction can be reduced significantly, in theory by up to a factor of 100. In practice, it has been shown that residual friction remains, for example due to incomplete lifting of the water, partial collapse of the air film, or hull surfaces not covered by air. To correctly assess this effect, it should be noted that hull friction accounts for approximately 90% of the total propulsion power at boat speeds of around 20 km / h and above. Theoretically, this friction power increases with the cube of the boat speed. At a boat speed of 20 km / h, water displacement when planing only accounts for around 10% of the propulsion power. The power required for water displacement only increases linearly with boat speed. This means that at higher speeds, hull friction is almost exclusively responsible for the boat's power requirements.In conclusion, it can be assumed that in almost all sports and fast workboats, the air jet unit according to the invention reduces the propulsion power, and thus the energy consumption, to up to approximately 10% of the conventional energy consumption. In addition to this energy saving, the oxygen input into the waters navigated is increased. Today, all bodies of water suffer from a notorious lack of oxygen. Thus, the invention can also have a positive effect from this perspective. Another advantage is that the reduction in propulsion power enables the use of alternative propulsion systems. Therefore, an electric motor is particularly preferably provided as the main propulsion system, which receives its energy from a battery. The watercraft can have a photovoltaic panel to charge the battery.

[0015] For the purposes of this disclosure, the location and direction specifications refer to the intended cruising position of the vessel on the body of water. "Forward" means closer to the bow, "aft" closer to the stern of the vessel. "Inward" and "outward" refer to the vertical plane of symmetry of the hull.

[0016] To accelerate the air flow before exiting the flat nozzle, a preferred embodiment of the flat nozzle has an air outlet section that opens into the elongated air outlet gap and tapers backwards when viewed in longitudinal section. Furthermore, the tapering of the air outlet section promotes a more uniform exit flow, thereby counteracting any possible collapse of the air film.

[0017] In a preferred embodiment, the flat nozzle has a front section which, viewed in longitudinal section, i.e., relative to a section parallel to the vertical plane of symmetry of the hull, rises towards the rear. The flat nozzle thus rises along the front section, starting from the front end of the flat nozzle towards the rear (i.e., opposite to the direction of travel). The flat nozzle preferably tapers backwards along the air outlet section to the elongated air outlet gap at the rear end of the flat nozzle. The flattening of the flat nozzle towards the front reduces water resistance. A connecting section can be provided between the front section and the air outlet section, which is preferably connected to the compressor via the air supply line, so that the compressed air flows from the compressor via the air supply line into the connecting section and from there into the air outlet section of the flat nozzle.

[0018] In a preferred embodiment, the elongated air outlet gap directly borders the adjacent section of the exterior of the hull, which is in contact with the water when the air nozzle unit is deactivated. The air outlet gap can be bounded on one side by the exterior of the hull and on the other side by a longitudinal web of the flat nozzle. In this embodiment, the longitudinal web also forms the water separation edge, at which the flowing water separates and is lifted off the exterior of the hull by the air film.

[0019] In a preferred embodiment, the elongated air outlet gap has a height (ie an extension perpendicular to the adjacent portion of the fuselage outer side) of 1 to 5 mm, for example substantially 3 mm.

[0020] The length of the air outlet gap depends on the dimensions of the vessel. If the vessel is a boat with a length of 6 to 10 m, the length of the air outlet gap can be 150 to 200 cm from the inner to the outer end.

[0021] Depending on the design, the length of the air outlet gap can be more than 150 cm, but also more than 250 cm, and especially more than 300 cm. The preferred length of the air outlet gap is between 150 cm and 200 cm.

[0022] In a preferred embodiment, the water separation edge extends at a distance of 1 to 5 mm, for example substantially 3 mm, from the adjacent portion of the outside of the hull.

[0023] In order to form an air film on each of the two longitudinal halves of the hull to reduce friction, the air nozzle unit in a preferred embodiment has an adjacent flat nozzle which is located essentially at the same longitudinal position as the flat nozzle in the central region of the hull, in particular in the region of the keel, and extends from there outwards, preferably also rearwards.

[0024] In order to further reduce water friction in a longer watercraft, in a preferred embodiment the air nozzle unit has a rear flat nozzle at a longitudinal distance (ie a distance seen in the direction of the longitudinal axis of the watercraft) behind the flat nozzle, preferably also an adjacent rear flat nozzle at a corresponding longitudinal distance behind the adjacent flat nozzle.

[0025] Depending on the length of the vessel, a central flat nozzle may also be provided, viewed longitudinally, between the flat nozzle and the rear flat nozzle and / or an adjacent central flat nozzle, viewed longitudinally, between the adjacent flat nozzle and the adjacent rear flat nozzle.

[0026] Preferably, the rear or middle flat nozzles described above are constructed like the front flat nozzles also described above, so that repetitions can be omitted.

[0027] In order to be able to adapt the respective air flows depending on the operation, in a preferred embodiment a control and / or regulating device is provided for controlling and / or regulating the respective air flow, in particular the mass flow of the respective air flow, from the elongated air outlet gap of the flat nozzle and / or from the elongated air outlet gap of the adjacent flat nozzle and / or from the elongated air outlet gap of the rear flat nozzle and / or from the elongated air outlet gap of the adjacent rear flat nozzle and / or from the elongated air outlet gap of the middle flat nozzle and / or from the elongated air outlet gap of the adjacent middle flat nozzle.

[0028] In a preferred embodiment, the control and regulating device for controlling and / or regulating the respective air flow from the respective air outlet gap, in particular the mass flow of the respective air flow, by adjusting the compressor, in particular by adjusting a speed of an impeller of the compressor, in particular of the radial compressor, and / or by adjusting a flow regulating element, in particular a throttle valve, for regulating the flow of the respective air flow.

[0029] To adapt the air flow exiting the air outlet gap to the operating and ambient conditions, the compressor can be controlled or regulated to increase or decrease the pressure provided by the compressor. If the compressor has an impeller, the air flow, particularly the mass flow rate, can be changed by adjusting the impeller speed.

[0030] Furthermore, the flow control element can be adjusted to adapt the flow resistance of the air flow before exiting the flat nozzle. If the air nozzle unit has several of the flat nozzles described above, several flow control elements are preferably provided in the respective air supply lines so that the air flows from the flat nozzles can be individually adjusted. Thus, the flow resistances along the air supply lines from the compressor to the air outlet gaps can be individually adjusted. This advantageously allows for individual adjustment of the individual air flows.

[0031] In a preferred embodiment, the control and / or regulating device comprises at least one sensor that preferably continuously detects at least one operating or environmental parameter of the watercraft. The measurement signal from the sensor serves as an input variable for controlling or regulating the respective air flow.

[0032] A travel speed sensor, preferably designed for installation in the water, such as a vane anemometer, an impeller, or a paddle wheel, can be provided as the sensor for detecting the travel speed of the watercraft. Thus, the compressor or the at least one flow regulating element can be adjusted depending on the travel speed. For example, the speed of the compressor can be increased and / or the flow resistance can be reduced by means of the flow regulating element when the travel speed of the watercraft increases. Conversely, the speed of the compressor can be reduced and / or the flow resistance can be increased by means of the flow regulating element when the travel speed of the watercraft decreases.

[0033] An air pressure sensor for detecting an air pressure in the air supply line between the compressor and the flat nozzle can also be provided as a sensor. In addition, at least one further air pressure sensor can be provided in a further air supply line between the compressor and one of the further flat nozzles, i.e. the adjacent flat nozzle, the rear flat nozzle, the adjacent rear flat nozzle, the central flat nozzle and the adjacent central flat nozzle. Preferably, further air pressure sensors are provided in all further air supply lines between the compressor and the further flat nozzles. Thus, the compressor or the at least one flow regulating element can be adjusted depending on the measured air pressure in the respective at least one air supply line.

[0034] A water pressure sensor can also be provided as a sensor for detecting the water pressure at the elongated air outlet gap of the flat nozzle. In this embodiment, at least one further water pressure sensor can also be provided for detecting the water pressure at the elongated air outlet gap of one of the further flat nozzles. Such water pressure sensors are preferably provided at the elongated air outlet gaps of all further flat nozzles. The at least one water pressure sensor is preferably arranged in the central region, in particular in the keel region, of the hull. The water pressure sensor can be used to detect how deep the respective measuring point is below the water surface. The measurement signal from the at least one water pressure sensor can be used to control the compressor or the at least one flow regulation element.

[0035] In a preferred embodiment, the control and / or regulating device is designed to allow the respective air flow to exit the elongated air outlet gap of the flat nozzle and / or the adjacent flat nozzle and / or the rear flat nozzle and / or the adjacent rear flat nozzle and / or the central flat nozzle and / or the adjacent central flat nozzle at an exit velocity that essentially corresponds to the traveling speed of the watercraft. This allows for particularly effective reduction of hull friction.

[0036] In a preferred embodiment, the control and / or regulating device is connected to a steering device for steering the watercraft, wherein the regulating device is designed to control or regulate the respective air flow depending on a current position of the steering device. In order to keep the air film on the outside of the hull as stable as possible when cornering, it is advantageous if the regulating device is coupled to the steering device for steering the watercraft. This allows the flat nozzle and the adjacent flat nozzle (and optionally the flat nozzles of the rear or middle nozzle pair) to be controlled differently depending on the position of the steering. This control can take into account that the two longitudinal halves lie at different depths in the water depending on the position of the steering, especially when cornering.

[0037] In a preferred embodiment, the control device is designed to control the flat nozzle and the rear flat nozzle, preferably also the adjacent flat nozzle and the adjacent rear flat nozzle, and particularly preferably also the middle flat nozzle and the adjacent middle flat nozzle, differently depending on the speed. This allows for the fact that the watercraft lifts more strongly out of the water with increasing speed, which changes the water pressure at the respective air outlet gaps.

[0038] The compressor preferably has an impeller whose speed is adjustable.

[0039] A radial compressor, also called a centrifugal compressor, is preferred as the compressor. A radial compressor is a turbo compressor or turbocharger in which the air to be compressed is set in rotation by an impeller running in a customized housing and accelerated from the inside out. In the subsequent diffuser, the kinetic energy is converted into pressure. The air flow can be adjusted by changing the speed of the impeller.

[0040] Furthermore, a side channel compressor can be provided as a compressor.

[0041] In a preferred embodiment, an ionizer for ionizing the air flow is arranged upstream of the flat nozzle. Ionizing the air downstream of the compressor allows for a more stable adhesion of the air film to the boat hull.

[0042] The method according to the invention for moving the watercraft comprises at least the following steps: Generating an air flow with a compressor and discharging the air flow along the outside of a hull of the watercraft, discharging the air flow from an elongated air outlet gap of a flat nozzle from a central area of ​​the hull to one of the two outer areas of the hull, lifting the water from the rear end of the flat nozzle, forming an air film behind the elongated air outlet gap of the flat nozzle between the outside of the hull and the water.

[0043] In a preferred embodiment, the method further comprises the following steps: An air flow flows out of an adjacent flat nozzle from one central area of ​​the hull to the other of the two outer areas of the hull, lifting the water from the rear end of the adjacent flat nozzle, forming an air film behind the adjacent flat nozzle.

[0044] In a preferred embodiment, the method further comprises the steps: Discharge of an air flow from a rear flat nozzle, preferably discharge of an air flow from an adjacent rear flat nozzle, lifting of the water from the rear end of the rear flat nozzle, preferably lifting of the water from the rear end of the adjacent rear flat nozzle, forming an air film behind the rear flat nozzle, preferably forming an air film behind the adjacent rear flat nozzle.

[0045] In a preferred embodiment, the method further comprises the steps of: regulating the respective air flow, in particular the mass flow of the respective air flow, from the respective air outlet gap of the flat nozzle and / or the adjacent flat nozzle and / or the rear flat nozzle and / or the adjacent rear flat nozzle depending on at least one operating or environmental parameter of the watercraft, wherein the at least one operating or environmental parameter preferably comprises: the current speed of the vessel and / or the air pressure in an air supply line between the compressor and the respective flat nozzle and / or the water pressure at a measuring point adjacent to the elongated air outlet gap and / or the position of a steering device of the vessel.

[0046] In a preferred embodiment, the respective air flow, in particular the mass flow of the respective air flow, controlled and / or regulated by adjusting the compressor, in particular by adjusting a speed of the compressor, in particular the radial compressor, and / or by flow regulation of the respective air flow.

[0047] The invention is further explained below with reference to an embodiment shown in the drawings. Fig. 1 shows a rear view of a watercraft according to the invention. Fig. 2 shows a sectional view of the vessel along the line AA in Fig. 1 . Fig. 3 shows a sectional view of the vessel along the line BB in Fig. 1 Fig. 4 shows a bottom view of the vessel in the direction of arrow D in Fig. 1 . Fig. 5 shows a sectional view of the vessel along the line FF in Fig. 4 . Fig. 6 shows detail E in Fig. 3 . Fig. 7 shows detail G in Fig. 5 . Fig. 8 shows a sectional view along a flat nozzle, which is arranged on the underside of the hull of the watercraft. Fig. 9 shows a detail of the Fig. 8 . Fig. 10 shows a side view of the flat nozzle from Fig. 8 , so that an elongated air outlet gap of the flat nozzle is visible. Fig. 11 shows a block diagram of a control device of the vessel of the Fig. 1 bis 10 .

[0048] Fig. 1 bis 5 show a watercraft 1, which in the embodiment shown is a planing vessel, here a planing boat. The planing boat has a hull 2 ​​in planing form. This means that the hull 2 ​​is shaped so that the planing boat lifts out of the water with increasing speed and glides on it. Thus, the planing boat can transition from a displacement mode to a planing mode. The planing boat has a (in Fig. 3 symbolically represented) main drive 1A, which is preferably an electric motor. The electric motor can be arranged at the stern of the watercraft 1. The main drive can be designed in any desired manner (not shown).

[0049] As from Fig. 1 bis 5 As can be seen, the watercraft 1 also has an air nozzle unit 3 with at least one (in Fig. 3 symbolically represented) compressor 4, which is in fluid communication with an arrangement of air nozzles 5. The compressor 4, which is in particular a radial compressor, generates a compressed air flow, hereinafter referred to as air flow, which is discharged via the individual air nozzles 5 along the underside of the fuselage 2.

[0050] As from Fig. 1 bis 5 As can also be seen, the arrangement of air nozzles 5 comprises a flat nozzle 6A and an adjacent flat nozzle 6B, which each extend, as seen in plan view (i.e., a bottom view of the ship's hull), from a central region of the hull 2, here from a keel 2A, outwards (i.e., toward the respective longitudinal side of the hull 2) and rearwards (i.e., toward the stern). The flat nozzle 6A and the adjacent flat nozzle 6B form a front nozzle pair, which is arranged closer to the bow than to the stern of the watercraft 1.

[0051] Furthermore, in the example shown, the air nozzle unit 3 has a rear flat nozzle 7A and an adjacent rear flat nozzle 7B, which also extend outward and rearward from the central region of the hull 2, here again from the keel 2A. The rear flat nozzle 7A and the adjacent rear flat nozzle 7B form a rear nozzle pair, which is arranged closer to the stern than to the bow of the watercraft 1.

[0052] Finally, in the example shown, the air nozzle unit 3 has a central flat nozzle 8A and an adjacent central flat nozzle 8B, which also extend outward and rearward from the central region of the hull 2, here from the keel 2A. The central flat nozzle 8A and the adjacent central flat nozzle 8B form a central nozzle pair, which, viewed in the longitudinal direction of the watercraft 1, is located between the front and rear nozzle pairs.

[0053] Depending on the length of the watercraft 1, the arrangement of air nozzles 5 can alternatively comprise only a single nozzle pair, exactly two nozzle pairs, or even more than the three shown. The flat nozzles of each nozzle pair are each identically designed and arranged in a mirror image with respect to a vertical center plane of the watercraft 1. When reference is made below to the flat nozzle 6A, these statements apply accordingly to the other flat nozzles. The flat nozzle 6A has a flattened shape, allowing the flat nozzle 6A to nestle against the hull 2.

[0054] As from Fig. 10 As can be seen, the flat nozzle 6A has an elongated air outlet gap 9 at the rear end, through which the air flow is jetted rearward. The air outlet gap 9 extends essentially over the entire length of the flat nozzle 6A, from an end near the keel to an end far from the keel. In addition, the flat nozzle 6A has a water separation edge 10 at the rear end, at which the water is spaced apart from the hull 2 ​​by the air flow from the air outlet gap 9. For this purpose, the air flow behind the elongated air outlet gap 9 of the flat nozzle 6A forms an air film, i.e. a flat layer of air, along the outside of the hull 2, which separates the hull 2 ​​from the water behind the flat nozzle 6A.

[0055] Fig. 8 shows a longitudinal section through the flat nozzle 6A parallel to the vertical center plane of the watercraft 1. Accordingly, the compressed air from the compressor 4 is directed towards the flat nozzle 6A via an air supply line 12. Further air supply lines 12 (not shown) lead to the other flat nozzles. The compressed air is conveyed through the hull 2 ​​into the flat nozzle 6A by means of a connecting part 13. The compressed air is then distributed laterally over the length of the flat nozzle 6A and flows rearwardly out of the flat nozzle 6A through the elongated air outlet gap 9. A check valve to prevent water ingress can be provided in the air supply line 12 or in the flat nozzle 6A (not shown).

[0056] As from Fig. 8 As can be seen, the flat nozzle 6A has an air outlet section 14 which opens into the elongated air outlet gap 9 and which tapers rearward in longitudinal section. Furthermore, the flat nozzle 6A has a front section 15 which, viewed in longitudinal section, rises rearward. The front section 15 is connected to the air outlet section 14 via a connecting section 16. The connecting part 13, via which the compressed air is introduced into the flat nozzle 6A, opens into the connecting section 16.

[0057] As from Fig. 8 As can be seen, the elongated air outlet gap 9 directly borders the outer side of the hull 2. In the example shown, the elongated air outlet gap 9 has a height of, for example, essentially 3 mm. The length of the air outlet gap 9 from the end near the keel to the end far from the keel is, for example, essentially 200 cm. In the example shown, the water separation edge 10 runs at a distance of, for example, essentially 3 mm from the outer side of the hull 2.

[0058] As from Fig. 8 As can be seen, the flat nozzle 6A in the example shown is designed as an attachment cap, which is attached to the hull 2 ​​of the watercraft 1 via fastening elements 17. Alternatively, the flat nozzle 6A can also be formed integrally with the hull 2.

[0059] As in Fig. 11As can be seen schematically, the watercraft 1 has a control device 19 with which the individual air flows of the air nozzle unit 3 can be controlled.

[0060] The control device 19 has a controller 20, which is connected to at least one sensor for detecting at least one operating or environmental parameter. In the example shown, several sensors are provided for detecting various operating and environmental parameters. Depending on the design, only one of these sensors or a selection of these sensors may be provided. The controller 20 can be connected to a travel speed sensor 21 for detecting the travel speed of the watercraft 1. Furthermore, the controller 20 can be connected to an arrangement of air pressure sensors 22, each of which measures the air pressure in the respective air supply line 12 between the compressor 4 and the respective flat nozzle 6A, 6B; 7A, 7B; 8A, 8B.In addition, the controller 20 can be connected to an array of water pressure sensors 23, each of which measures the local water pressure adjacent to the respective air outlet gap 9 of the respective flat nozzle 6A, 6B; 7A, 7B; 8A, 8B. Preferably, the water pressure sensors 23 are located adjacent to the keel-side end of the respective air outlet gap 9. Finally, the controller 20 can be connected to a steering device 24 for steering the watercraft 1, so that the respective air flow can be controlled or regulated depending on a current position of the steering device. This allows, for example, cornering to be taken into account during control.

[0061] The various sensors supply the input signals for the controller 20, which uses the input signals from the sensors to create corresponding control signals for adjusting the individual air flows from the air outlet gaps. For this purpose, the controller 20 is connected to the compressor 4 so that the air pressure provided by the compressor 4 can be adjusted. If the compressor 4 is a radial compressor or a side channel compressor, the controller 20 can regulate the speed of the compressor in order to adjust the pressure ratio compared to the ambient pressure. In the example shown, the controller 20 is also connected to an arrangement of flow regulating elements 25, in particular throttle valves, for regulating the flow of the respective air flow, i.e. for influencing the flow resistance, in the respective air supply line 12.

[0062] With the control device 19, the respective air flow can be jetted out of the flat nozzles 6A, 6B; 7A, 7B; 8A, 8B at an exit speed that essentially corresponds to the traveling speed of the watercraft 1. Furthermore, the current immersion depth of the respective flat nozzle 6A, 6B; 7A, 7B; 8A, 8B into the water can be taken into account. The nozzle pairs can have different immersion depths due to their different longitudinal positions on the hull 2. Furthermore, the immersion depth changes due to the traveling speed of the watercraft 1. Finally, the immersion depths of the two flat nozzles of each nozzle pair can constantly change relative to one another because the watercraft 1 is subject to fluctuations or is cornering.By continuously controlling the compressor 4 and the flow control elements 25 depending on the input signals from the sensors, the air films behind the flat nozzles 6A, 6B; 7A, 7B; 8A, 8B can be reliably maintained.

Claims

1. Watercraft (1), in particular a glider, comprising: a hull (2), a main drive (1A), preferably an electric drive, in particular at least one electric rear motor, an air nozzle unit (3) with a compressor (4), in particular with a radial compressor, for generating an air flow, with an air supply line (12) carrying the air flow and with an air nozzle (5) connected to the compressor (4) via the air supply line (12) for applying the air flow to the outside of the hull (2), characterized by that a flat nozzle (6A) is provided as the air nozzle (5), which extends, as seen in plan view, from a central region of the fuselage (2) outwards, preferably also rearwards, that the flat nozzle (6A) has an elongated air outlet gap (9) at the rear end for the outlet of the air flow and thatthe flat nozzle (6A) has a water separation edge (12) at the rear end, so that an air film can be formed along the outside of the fuselage (2) behind the elongated air outlet gap (9) of the flat nozzle (6A).

2. Watercraft (1) according to claim 1, characterized in that the flat nozzle (6A) has an air outlet section (14) which opens into the elongated air outlet gap (12) and which, viewed in longitudinal section, tapers rearwards.

3. Watercraft (1) according to claim 1 or 2, characterized in that the flat nozzle (6A) has a front section (15) which rises rearwards when viewed in longitudinal section.

4. Watercraft (1) according to one of claims 1 to 3, characterized in thatthe elongated air outlet gap (12) has a height of 1 to 10 mm, for example substantially 3 mm, and / or a length of 50 cm to 300 cm, wherein the water separation edge (12) preferably extends at a distance of 1 to 10 mm, for example substantially 3 mm, from the outside of the hull (2).

5. Watercraft (1) according to one of claims 1 to 4, characterized in thatthe air nozzle unit (3) further comprises: an adjacent flat nozzle (6B) which is located essentially at the same longitudinal position as the flat nozzle (6A) in the central region of the fuselage (2) and extends from there outwards, preferably also rearwards, and / or a rear flat nozzle (7A) at a longitudinal distance behind the flat nozzle (6A) and / or an adjacent rear flat nozzle (7B) at a corresponding longitudinal distance behind the adjacent flat nozzle (6B), preferably also a middle flat nozzle (8A) viewed in the longitudinal direction between the flat nozzle (6A) and the rear flat nozzle (7A) and / or an adjacent middle flat nozzle (8B) viewed in the longitudinal direction between the adjacent flat nozzle (6B) and the adjacent rear flat nozzle (7B).

6. Watercraft (1) according to claim 5, characterized in thata control and / or regulating device (19) for controlling and / or regulating the respective air flow, in particular the mass flow of the respective air flow, from the elongated air outlet gap (9) of the flat nozzle (6A) and / or the adjacent flat nozzle (6B) and / or the rear flat nozzle (8A) and / or the adjacent rear flat nozzle (8B) and / or the middle flat nozzle (8A) and / or the adjacent middle flat nozzle (8B) is provided.

7. Watercraft (1) according to claim 6, characterized in thatthe control and regulating device (19) is designed to control and / or regulate the respective air flow, in particular the mass flow of the respective air flow, by adjusting the compressor (4), in particular by adjusting a speed of an impeller of the compressor (4), in particular of the radial compressor, and / or by adjusting a flow regulating element (25), in particular a throttle valve, for regulating the flow of the respective air flow.

8. Watercraft (1) according to claim 6 or 7, characterized in thatthe control and / or regulating device (19) comprises: a travel speed sensor (21) for detecting the travel speed of the watercraft (1) and / or an air pressure sensor (22) for detecting an air pressure in the air supply line between the compressor (4) and the flat nozzle (6), preferably at least one further air pressure sensor in a further air supply line (12) between the compressor (4) and the adjacent flat nozzle (6B) or the rear flat nozzle (7A) or the adjacent rear flat nozzle (7B) or the middle flat nozzle (8A) or the adjacent middle flat nozzle (8B), and / or at least one water pressure sensor (23) for detecting the water pressure at the elongated air outlet gap (9) of the flat nozzle (6a), preferably at least one further water pressure sensor (23) for detecting the water pressure at the elongated air outlet gap (9) of the adjacent flat nozzle (6B) or the rear flat nozzle (8A) orthe adjacent rear flat nozzle (8B) or the middle flat nozzle (8A) or the adjacent middle flat nozzle (8B).

9. Watercraft (1) according to one of claims 6 to 8, characterized in that the control and / or regulating device (19) is designed to allow the respective air flow to exit the elongated air outlet gap (9) of the flat nozzle (6A) and / or the adjacent flat nozzle (6B) and / or the rear flat nozzle (8A) and / or the adjacent rear flat nozzle (8B) and / or the middle flat nozzle (8A) and / or the adjacent middle flat nozzle (8B) at an exit speed that substantially corresponds to the travel speed of the watercraft (1).

10. Watercraft (1) according to one of claims 6 to 9, characterized in thatthe control and / or regulating device (19) is connected to a steering device (24) for steering the watercraft (1), wherein the regulating device (19) is designed to control or regulate the respective air flow depending on a current position of the steering device (24).

11. A method for moving a watercraft (1), preferably according to one of claims 1 to 10, in particular in planing mode, on a body of water, comprising the steps of: generating an air flow with a compressor (4), in particular with a radial compressor, and discharging the air flow along the outside of a hull (2) of the watercraft (1), characterized by The air flow flows out of an elongated air outlet gap (12) of a flat nozzle (6A) from a central region of the hull (2) to one of the two outer regions of the hull (2), the water is lifted off from the rear end of the flat nozzle (6A), and an air film is formed behind the elongated air outlet gap (12) of the flat nozzle (6A) between the outside of the hull (2) and the water.

12. Method according to claim 11, characterized by : Discharge of an air flow from an adjacent flat nozzle (6B) from a central region of the hull (2) to the other of the two outer regions of the hull, lifting of the water from the rear end of the adjacent flat nozzle (6B), forming an air film behind the adjacent flat nozzle (6B) between the outside of the hull (2) and the water.

13. Method according to claim 11 or 12, characterized by: outflow of an air flow from a rear flat nozzle (7A), preferably outflow of an air flow from an adjacent rear flat nozzle (7B), lifting of the water from the rear end of the rear flat nozzle (7A), preferably lifting of the water from the rear end of the adjacent rear flat nozzle (7B), forming an air film behind the rear flat nozzle (7A), preferably forming an air film behind the adjacent rear flat nozzle (7B).

14. Method according to one of claims 11 to 13, characterized by: Regulating the respective air flow, in particular the mass flow of the respective air flow, from the flat nozzle (6A) and / or from the adjacent flat nozzle (6B) and / or from the rear flat nozzle (7A) and / or from the adjacent rear flat nozzle (7B) depending on at least one operating or environmental parameter of the watercraft (1), wherein the at least one operating or environmental parameter preferably comprises: the current travel speed of the watercraft (1) and / or the current water pressure at a measuring point adjacent to the elongated air outlet gap (9) and / or the current position of a steering device (24) of the watercraft (1).

15. Method according to one of claims 11 to 14, characterized in thatthe respective air flow, in particular the mass flow of the respective air flow, is controlled and / or regulated by adjusting the compressor (4), in particular by adjusting a speed of the radial compressor, and / or by flow regulation of the respective air flow.

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