Patent Application
20240424370
The invention relates to a device and method for generating a standing surfable wave.
A standing surfable wave can be generated by using a system that routinely generates waves on a body of water. These systems use air, water, or a combination of the two to generate waves that are suitable for surfing spots. Natural phenomena such as tidal waves and ocean currents can also generate surfable waves. It is important to note, though, that not every wave is surfable and a good surfing wave must have certain characteristics such as size, shape, and duration.
A standing surfable wave is a paradox since waves normally transport energy and therefore cannot “stand still”. A wave that is suitable for surfing must be in motion. There are, however, wave parks where artificial waves are generated through the use of systems that allows surfers to surf on a sustained wave. In such parks, the energy required to generate the wave is constantly replenished in order to maintain a sustained wave.
It is known to generate a surfable wave by means of an inclined surface, for example a ramp, which is used to accelerate slow-flowing water into fast-flowing water. At the end of the ramp, the shooting water meets flowing water and a hydraulic alternating jump is produced in the transition zone. If the tailwater level is suitable, a standing surfable wave is generated at the hydraulic jump. Usually, the wave is regulated by changing the inclination of the ramp and, if necessary, by changing a spoiler at the end of the ramp.
The hydraulic alternating jump is produced at the flow transition from the shooting discharge to flowing discharge. It is an abrupt change in flow from very fast to very slow flowing water. One example of a hydraulic jump is an eddy.
If the discharge is faster than the propagation velocity of disturbances (waves), this is referred to as shooting or supercritical discharge (Fr>1).
If the discharge is slower than the propagation velocity of disturbances, this is referred to as flowing or subcritical discharge (Fr<1).
The Froude number is used for differentiation:
US 2008/0101866 A1 describes wave-generating systems that are positioned in a channel and form a control section by means of a ramp, in which the water is concentrated and accelerated and the wave is generated by the impact of the water against an adjustable edge and the wave height is varied.
DE 10 2006 044 806 B4 describes a device for generating standing waves which, in the flow direction, comprises a transverse structure, a ramp, a counterpart ramp, a bottom, and a flow guide body. The acceleration of the water is regulated via mechanically movable ramps. And the wave is generated on a rigid plate that is supported in articulated fashion at the downstream end of the ramp.
WO 2018 149 969 A1 discloses a wave system for generating an artificial wave, wherein the system consists of a storage basin, an intermediate basin, a wave basin, and at least one conveying means, in particular at least one pump. The pump is used to convey water from a storage basin via the intermediate basin into the wave basin. The water is fed into the wave basin via the outlet of the intermediate basin and via a downward inclined ramp. A guide device for generating a wave is provided in the wave basin. In this case, the height of the wave is manipulated by means of the height of the guide device under water, which can be adjusted so that the flowing water meets a lower or higher resistance at the bottom, thereby generating a higher or lower wave on the surface of the water.
DE 103 08 812 B4 discloses a device for generating a standing wave in a flowing body of water, which comprises a transverse structure in the flow direction that serves as the first flow influencing body and concentrates the water flow. Via a guide ramp, a shooting jet is directed at a base point of a flexible wave generating body to generate the wave.
DE102006044806A1 discloses the generation of straight standing waves through the use of a ramp, a counterpart ramp, and a control mechanism. Since the ramp and counterpart ramp are permanently connected in this case, it is only possible to change the height or angle of both the ramp and counterpart ramp.
Basically similar components in laboratory systems or test flumes have been described in international publications (“A stationary oblique breaking wave for laboratory testing of surfboards” by H. G. Hornung and P. Killen, Journal of Fluid Mechanics, 1976; “Hydrodynamics of Surfboards” by Michael Paine, 1974).
EP 0 547 117 B2 and EP 0 629 139 B1 describe devices for generating wave-like water surfaces of low flow depth and high speed in man-made leisure facilities. In this case, a planar current is generated that is directly applied to a wave-like body. The systems designed for flowing bodies of water, however, are not able to produce waves for leisure activities of a quality similar to those produced by such facilities with artificially generated currents.
U.S. Pat. No. 6,932,541 B2 describes a system in which standing waves are generated by the hydraulic interaction of a flow over a weir or over bed structures with a secondary flow through the weir or the bed structures. The secondary flows can be controlled by the movable design of the weir or bed structures. The documents also describe an embodiment without secondary flow. In this case, no mobility of parts of the weir or the bottom structures is provided. In all of the embodiments, the standing waves are generated directly above the bed structures. The flow guidance through the bed structures is essential for the production of the waves.
DE 10 2004 016 750 A1 describes a mobile standing flow wave that is to be generated by temporarily constricting the flow with two damming elements and a mobile ramp-like structure. The damming and constriction are supposed to result in the generation of a significantly accelerated flow motion through the constriction point. Under favorable boundary conditions, a standing wave can then form below the constriction point. It is not possible to control this wave.
DE 10 2004 013 367 A1 describes devices for designing a water obstacle course. Movable elements provided at the bottom are also described therein, which can influence the flow depending on their position. It is not possible, however, to use this to control standing waves.
It is known that ramps, particularly ones that are inclined in the flow direction and have a subsequent height offset downstream, are suitable for generating straight standing waves (among others, for example from: “Erzeugung von Wellen und Walzen für den Kanusport” [Generation of Waves and Eddies for Canoeing], report by the Institute of Hydraulics at the German Federal Armed Forces Academy in Neubiberg commissioned by the Bavarian Canoe Association, March 2004). In this case, the formation of waves is stimulated in particular by the abrupt deceleration of the flow at the transition between the shooting flow motion on the ramp (Froude number >1) and a slower-moving flow motion downstream of the ramp (Froude number <1). In this context, the water level below the device is of particular importance for the formation of a standing wave.
A continuous flow of liquid is a laminar flow. In order to generate a wave in such a flow, the flow must be disturbed by a wave excitation element. This wave excitation element can be an uneven zone, an edge, or a guiding element.
It is known to accelerate slow-flowing water to produce fast-flowing water by means of an inclined surface such as a ramp. When the accelerated water flow meets the slow-flowing water flow at the end of the ramp, the hydraulic alternating jump is produced at the transition zone. With a suitable tailwater level, a standing surfable wave is generated at this hydraulic alternating jump.
It is usually possible to regulate the height of the wave by changing the inclination of the ramp itself or by changing a spoiler at the end of the ramp. For this reason, flexible ramps with adjustable inclination are usually used. The mechanism for adjusting the inclination is situated under water in this case.
DE 103 08 812 B4 discloses a device for generating a standing wave in a flowing body of water, which comprises a transverse structure in the flow direction that serves as a first flow-influencing body and concentrates the water flow. The flow is directed to the base of a flexible wave generating body by means of a spatially curved guide ramp with an increasingly acute angle. This device is particularly suitable for generating standing waves, especially breaking waves.
A disadvantage of the known systems is that all of the mechanically moving parts are situated below the water surface and therefore can only be accessed for maintenance and repairs with considerable effort. The majority of known systems require the flowing body of water to be drained during maintenance and repair work, which is only possible seasonally and is very costly, especially in the case of flowing bodies of water with a natural flow. In addition, the maximum width of the system with movable elements is limited in terms of the design by the load limits of the individual elements. Larger widths can only be achieved by stringing together a plurality of individual systems, which multiplies the number of mechanical components—and thus the susceptibility to errors and error frequency of the overall system—by the number of individual systems.
Another disadvantage of known systems is that different flow rates on the ramp result in different waves so that it is not possible to produce constant surfing conditions.
Basically, known devices for generating standing surfable waves generate them continuously by either pumping water to a ramp that it runs down or by erecting a weir that the water overflows and then runs down a ramp, which is situated downstream of the weir and adjoins the upper edge of the weir.
In hydraulic engineering, a weir is a device that extends from the bottom and banks or side walls of a flowing body of water, blocking the flow path; such a weir is then overflowed by the current.
By contrast, a gate in hydraulic engineering is a device that blocks a flowing body of water from above and can be raised to allow the water to flow at or along the bottom of the water body and thus allow a flow regulation.
The object of the invention is to provide a device for generating a standing surfable wave, which is easy to maintain, inexpensive to operate, and also ensures a high degree of adjustability of the wave.
Another object of the invention is to create a method for generating a surfable wave that generates a surfable wave reliably and constantly regardless of the existing current.
In a departure from existing designs for generating surfable waves, the invention does not require the use of a weir or the pumping of water. In addition, it is not absolutely necessary to build a steep ramp.
A device according to the invention can be installed in natural or artificial currents, regardless of the longitudinal gradient, with a low longitudinal gradient, with a high longitudinal gradient, or also at gradient steps such as existing weirs. In addition, a significantly lower damming height is required ahead of the wave, which is why the system can also be used in existing channels with a low bank elevation. Furthermore, the arrangement of a bypass channel does not interfere with bed load management in natural flowing bodies of water.
According to the invention, natural bodies of water or artificial bodies of water such as canals that have a certain gradient can be used for producing a standing surfable wave. In this connection, even higher water speeds can be achieved, which are higher than on corresponding acceleration ramps.
According to the invention, a bottom of a water body or canal is provided, which has a certain slope. A ramp is provided on this canal bottom, which projects away from the canal bottom and causes water flowing along the canal bottom to be deflected away from the canal bottom. Downstream of the ramp, the bottom of the canal or water body is lowered with a step and extends from there at a height level situated below that of the canal bottom upstream of the ramp. This creates a basin downstream of the ramp.
An additional ramp may be provided in this basin, which is arranged in such a way that the water that is accelerated upward via the ramp and then falls into the basin preferably strikes this ramp in such a way that the water flow preferably strikes this ramp perpendicularly. This second ramp in the basin causes a surprising increase in the height of the wave formed by the first ramp. It is not yet entirely possible to explain what causes this surprising effect.
This wave can be modulated by means of the volume of water that is directed via the canal bottom to the first ramp.
There are basically two possibilities for this. In the case of a flowing body of water with a high flow rate of the water, modulation can take place by means of a bypass, which guides a corresponding volume or excess volume of water laterally past the device. For this purpose, a corresponding regulating or damming device can be provided in the bypass, which can be used to regulate the water volume.
In another embodiment, a gate is provided upstream of the ramp and can be used to regulate the water volume. In the simplest case, the gate here can be a wall extending transversely to the flow direction, which can be lowered into the body of water to a bottom of the water body or canal and lifted up away from it. This dams the water upstream of the gate. A corresponding volume of water is then guided via the canal bottom and under the gate, which is sufficient to form a corresponding wave at the ramp.
To prevent an overflowing of the gate, a gate can also be combined with a bypass, in particular a controllable bypass. In particular, the gate can also be designed as a flap that can be lowered onto the water surface and into the water, thus modulating the water flow and consequently also the wave. In this connection, it is also possible to use a flap that extends across the entire width of the water, but the flap can also be made up of several individual flaps that can be controlled differently. This is achieved by lowering one flap more than the others. This can be understood as similar to what happens with the stern wave of a ship, which also varies depending on the displacement. Due to the various possibilities for modulating the wave, such a flap gate is ideally suitable for generating a surfable wave.
By means of the device according to the invention, the water of a waterway such as a stream, river, or canal is regulated with a gate. Excess water can be carried away by means of a bypass. In this case, the bypass can also have a flow limiter.
If the gradient, water volume, and water speed are right, it is also possible to use a bypass without a gate. The gate is capable of increasing the speed of the flowing water if there is no gradient.
An additional advantage of the embodiment with flaps is that the water for the acceleration is manipulated from above and there are no bodies penetrating the water surface downstream of the interrupting edge of the flaps. In contrast to systems with a free surface during the acceleration, manipulations before the maximum constriction of the flow cross-section, i.e. before the interrupting edge of the flaps, have no influence on the flow after it.
The gate is preferably a gate that acts on the water surface from above with at least one flap. Depending on the width of the body of water, the flap can span the body of water and can be arranged in pivoting fashion so that it can be actuated on the banks outside the body of water. If the body of water is too wide for this, then the flap gate can be elevated in the water and can have a supporting structure on which the at least one flap is arranged so that it can be actuated in pivoting fashion.
In any case, the means for actuating the flaps are situated outside the water.
In the embodiment that is elevated in the water, the supports or columns are positioned upstream of the actual flaps so that they do not negatively affect the water flow at the level of the flaps (any longer). The supports or columns can also be streamlined.
Consequently, the invention particularly relates to a device for generating a standing surfable wave, wherein the device is embodied in the form of a channel with two flow-limiting banks or walls and a bottom of the water body situated between them, wherein the depth of the bottom of the water body increases by means of a step to form a stilling basin and the bottom of the stilling basin is positioned below the level of the bottom of the water body, wherein a ramp is formed on the bottom of the water body before the stilling basin in the flow direction, which ramp extends away from the bottom of the water body, and in the stilling basin, a ramp-like flow body is embodied on the bottom of the stilling basin.
In one modification, a gate or a bypass for guiding water past the ramp and the stilling basin—or both a gate and a bypass—are positioned upstream of the ramp to regulate the volume of water and/or to regulate the flow velocity.
In one modification, the gate is positioned essentially transversely to the flow direction in the body of water.
In one modification, the distance between the gate and the ramp is set to 1.5-5 m, in particular 2-4 m.
In one modification, the flow body in the stilling basin is positioned in such a way that water, which flows over the ramp and forms the wave, strikes the flow body essentially perpendicularly, in particular at an angle of 90°±25°.
In one modification, the flow body is embodied as ramp-like and has a front flank in the flow direction, which is inclined toward the bottom of the stilling basin, wherein the inclination is set according to the flow pattern of the water striking it and in particular, is between 15 and 565°, especially between 25 and 55°.
In one modification, the flow body extends over a partial width of the stilling basin, extends over the entire width of the stilling basin, or slopes down to the bottom of the stilling basin toward the side walls that delimit the stilling basin.
In one modification, the ramp has a control surface situated toward the front in the flow direction, wherein the control surface extends from a bottom of the water body to a top of the ramp in the form of an at least partially concave and in particular brachistochrone curve.
In one modification, the ramp is positioned in such a way that the top of the ramp is aligned with a step that increases the depth of the bottom of the water body to that of the stilling basin.
In one modification, the gate is embodied as a flap gate, wherein gate flaps are provided, which can be pivoted toward a surface of a body of water and pivoted into the body of water in order to limit the effective flow cross-section of the body of water from the bottom of the water body to the free rear edges of the gate flap.
In one modification, the gate has a gate base plate whose rear edge in the flow direction has one or more gate flaps arranged on it in an articulated and pivotable fashion.
In one modification, a gate flap or a plurality of gate flaps are arranged so that they can be actuated and pivoted individually.
In one modification, the gate base plate is positioned on the banks, extending across the body of water transversely to the flow direction, or is elevated with support columns on the bottom of the water body or rests on the banks or is positioned between them and rests against them and is elevated relative to the bottom of the water body.
In one modification, one or more gate flaps and in particular a middle gate flap has a displacement body with which the water displacement can be increased in this zone.
In one modification, in the region of the gate, the bottom of the water body is formed with a section in which the gradient is greater than in the region of the rest of the bottom of the water body before and after the gate.
In one modification, the gate is elevated on a wall element that is formed by the bottom of the water body, wherein the wall element rises a little above the bottom of the water body with a front wall that transitions into a plateau on which the gate is elevated or across which the gate extends, wherein the plateau has a gradient corresponding to that of the bottom of the water body or has no gradient, wherein at a rear edge in the flow direction, the wall element forms an interrupting edge, which extends transversely to the flow direction, and then extends with a convexly curved rear wall into a section of the bottom of the water body, whose depth can be lower than the bottom of the water body before the wall element. This is also used when adapting existing weirs.
In one modification, the gate with its gate base plate extends parallel to the plateau of the wall element and the gate flaps are positioned so that they act with their rear edge on the body of water downstream of the interrupting edge in the region of the concave rear wall.
In one modification, a displacement mechanism is positioned upstream of the ramp on the bottom of the water body and is connected to the bottom of the water body, wherein the displacement mechanism has a pivoting displacement plate that can be placed transversely into the flow. The displacement mechanism reduces the flow cross-section and leads to a higher flow velocity on its flanks. Downstream of the displacement mechanism where the water from the flanks converges again, the height of the wave increases.
A further aspect of the invention relates to a method for generating a surfable wave, wherein in a section of a natural or artificial body of water such as a river, stream, or canal, a ramp is positioned on a canal bottom essentially transversely to the flow direction and piles up water to form a wave, wherein a stilling basin is provided after the ramp, which has a stilling basin bottom that is positioned deeper than the bottom of the water body upstream of the ramp, wherein in a region in which the water flows into the stilling basin, a ramp-like flow body for modulating the wave is positioned in such a way that the water strikes perpendicularly against a front flank of the flow body.
In one modification, in order to regulate the volume of water or to regulate the speed of the water flowing over the ramp or to regulate both the volume of water and speed of the water flowing over the ramp, before the ramp, the water is guided via a bypass that extends past the ramp and the stilling basin, or the volume of water and water speed are regulated with a gate that is positioned before the ramp, or both a bypass and a gate are provided.
In one modification, the gate is used to adjust the effective flow cross-section of the water between the banks and the bottom of the water body on the one hand and an edge of the gate on the other.
In one modification, the gate is used to change the water flow from a flowing motion to a shooting flow motion and to change the transition from a Froude number with a value less than 1 to a Froude number with a value greater than 1.
In one modification, the distance between the gate and the ramp, and in particular between the effective rear edge of the gate and the ramp, is set to 1.5-5 m, in particular 2-4 m.
In one modification, the inclination of the front flank of the flow body is fixed or variably adjustable, wherein depending on the flow pattern of the water, the inclination is set to 15-55°, in particular between 2° and 45°.
In one modification, a gate is used, with a gate base plate and with a gate flap joined in articulated fashion to a rear edge of the gate base plate, wherein the gate flap has the edge that can be pivoted down onto the body of water and into the body of water, wherein the gate base plate is embodied as parallel to the bottom of the water body or inclined toward the bottom of the water body in the flow direction, wherein the effective flow cross-section is reduced by the inclined gate base plate so that the gate base plate reduces the effective flow cross-section at a rear edge between the bottom and banks of the water body and the rear edge so that the flow velocity is increased.
In one modification, the ramp accelerates the incoming water with a control surface situated toward the front in the flow direction, wherein from a bottom of the water body to a top of the ramp, the control surface for accelerating the water is embodied as an at least partially concave and in particular brachistochrone curve.
In one modification, in order to produce a hydraulic jump, the water is accelerated at the transition from the flowing water to the shooting water of the control surface embodied as a brachistochrone curve.
The invention will be explained by way of example with the aid of the figures. In the drawings:
A system 200 for establishing a surfing wave according to the prior art is shown in
Instead of a body of water 201, water can also be fed in this case from the stilling basin 208 to the start of the ramp 205 or to the connection point to a weir, which would then not be necessary, and in particular pumped in circulation, and can run down the ramp. The flow velocities that can be achieved with such systems are between 2 and 4 m/s.
In this case, it is clear that the height h1, which describes the maximum height of the body of water in the vicinity of the start of the ramp 205 down to the water level in the stilling basin 208, is comparatively high.
A device 1 according to the invention for generating a surfable wave is formed in or with a body of water 2, wherein the body of water 2 has a bottom 3. In the flow direction S of the water, at least a first ramp 4 is positioned on the bottom 3 of the water body and extends away from the bottom, in particular at an angle. After the ramp 4, the bottom 3 of the water body drops down with a step 5 to a bottom 6 of a stilling basin 7.
The stilling basin 7 can be raised again to an upper level of the bottom 3 of the water body with a further step 8. With such an arrangement, the formation of a surfable wave 9 is possible if the speed of the water is sufficient. In order to regulate the water flow in this case, a bypass (not shown) can be provided parallel to the body of water 2, particularly in the form of a channel with an adjustable flow resistance, which is embodied to guide part of the water 2 past the device 1.
In particular, however, the formation of the surfable wave 9 is achieved with a gate 10. The gate 10 in this case is arranged essentially transverse to the flow direction(S) in the body of water 2, with the water flowing through under the gate, thereby achieving a higher flow velocity. In this case, the gate reduces a first level 11 of the water to a second, lower level 12. The flow velocities that can be achieved with a gate 10 are higher than those of conventional weir systems.
The gate 10 is used to transform the discharge from a flowing flow motion into a shooting flow motion and thus serves to transform the flow state from a Froude number with a value less than 1 to a Froude number with a value greater than 1.
The distance between the gate 10 and the ramp 4 is preferably selected so that sufficient space remains for a surfer and in particular 1.5 to 5 m, especially 2 to 4 m. Compared to the known embodiments in
It is clear that the required gradient or required level difference is significantly lower with the method and device according to the invention (
The ramp 4 is only shown in highly schematic form; it can also be a ramp 4 situated on the bottom 3 of the water body, which can also be made of concrete, for example, and in particular can also have a concave side facing the flow.
It is clear how the ramp 4 deflects the water 2 upward so that a wave 9 forms. In this case, the solid line 13 shows the shape of the wave 9 as it will normally occur, with the water flowing into the stilling basin 7 along line 14.
Surprisingly, it has turned out that if a flow body 15 is arranged in the stilling basin 7 in accordance with the invention, the wave 9 can be built up even better. The shape of the wave 9 with the flow body 15 according to the invention is indicated by the dashed line 16, with the water in the wave flowing into the stilling basin along the dashed line 17.
The flow body 15 in this case is positioned in such a way that the water flowing according to the flow path 17 strikes the flow body 15 as perpendicularly as possible. This quite clearly results in an increased height of the wave 9.
For this purpose, the flow body 15 has a front flank 18 in the flow direction(S), which is inclined relative to the stilling basin bottom 6. The inclination is set according to the flow pattern of the water striking it and can be between approximately 20° and 45°.
The flow body 15 in this case can extend across the entire width of the stilling basin 7, but if the wave is only to be modulated in a central area, for example, then the flow body can also drop down to the stilling basin bottom 6 at the edges.
The flow body 15 can be attached to the stilling basin bottom 6 and can theoretically also be detachable and therefore replaceable. In addition, however, the flow body 15 can also be integrally connected to the stilling basin bottom 6 or be formed by the stilling basin bottom 6.
In this embodiment, the gate 10 extends from a first bank 20 delimiting the body of water 2 to an opposite bank 21 delimiting the body of water 2.
The banks 20, 21 here can be natural embankments, but the body of water can also be a canalized flowing body of water in which the banks 20, 21 are correspondingly embodied as essentially vertical walls. It is essential for the banks to be able to close off the sides of the body of water 2 in such a way that the flow path of the water is maintained over the entire length of the device 1.
The gate 10 has a first gate base plate 22. The gate base plate 22 preferably extends over the entire width of the body of water 2 between the first bank 20 and the second bank 21. In the case of a body of water 2 that has a limited width, the gate base plate 22 can rest on the banks 20, 21 and be fixed there or can be fixed to the banks 20, 21 spanning the body of water. If the body of water between the banks 20, 21 is sufficiently wide, the gate base plate 22 can be elevated with support columns 23 on the bottom 3 of the water body. In this case, the support columns 23 extend upward from the bottom 3 of the water body to the gate base plate 22 and are connected both to the bottom of the water body and to the gate base plate 22.
The support columns 23 can have a cross-section that is round or, as shown in
At a front edge 24 of the gate base plate 22, rake bars 25 can extend from the front edge 24 to the bottom 3 of the water body and form a rake 26, which prevents larger objects carried along with the flow from getting caught in the system or device 1 and damaging it. In particular, the rake bars 25 can be positioned extending at an angle from the front edge 24 to the bottom 3 of the water body. To prevent blockages, the rake bars can be lifted out of the water by means of an articulation outside the operation times of the wave.
A rear edge 27 is formed onto the gate base plate 22 at the opposite end from the front edge 24 in the flow direction.
The front edge 25 and rear edge 27 preferably extend essentially parallel to each other and transversely to the flow.
Between the front edge 24 and the rear edge 27, the gate base plate 22 can be inclined in such a way that the front edge 24 is higher, i.e. spaced a greater distance apart from the bottom 3 of the water body, than the rear edge 27 of the gate base plate 22. This inclination lowers the level 11 of the body of water 2 before the gate 10 to a level 12 which essentially corresponds to the height of the rear edge 27 relative to the bottom 3 of the water body. In other words, when the gate flaps are producing a damming effect, the gate base plate 22 dams up the incoming surge water to above the level of the headwater level.
Along the rear edge 27, gate flaps 28 are positioned on the gate 10 or on the gate base plate 22. Depending on the width of the body of water 2 and thus also the length of the gate base plate 22 between the banks 20, 21, one gate flap 28 or multiple gate flaps 28 can be provided. The one gate flap or multiple gate flaps 28 are arranged in pivoting fashion on the gate base plate 22 by means of an articulation 29.
The pivoting action in this case is ensured in such a way that a front edge 30 of the gate flaps in terms of the flow is connected to the articulation 29 and a rear edge 31, which is remote from the front edge 30 in the flow direction, can be pivoted toward and away from the bottom 3 of the water body. In this case, the gate flap 28 or gate flaps 28 can also be raised above the level of the rear edge 27 so that the gate flaps 28 do not dip into the water and do not constrict the flow cross-section any more than the gate base plate 22 does.
But the flow area for the water can be further reduced by means of the gate flaps 28, in particular with the rear edge 31, and in particular reduced by means of the bottom 3 of the water body, the banks 20, 21, and the rear edge 31 to such an extent that a level 19 can be achieved at which the flow velocity is further increased. It is clear from the corresponding dashed lines in
If there are several gate flaps 28, these can preferably be controlled differently, which is possible by means of a coaxial arrangement of hollow or solid shafts along the front edges 30 so that each gate flap 28 has its own hollow or solid shaft.
The actuating mechanisms for the gate flaps 28 are preferably situated in the region outside the water.
In order to prevent the water 2 from backing up too much and overflowing the front edge 24 of the gate base plate when the flaps are lowered and the flow velocity is high, a bypass can be provided, as stated above, with which the level 11 of the water 2 upstream of the gate can be adjusted as needed if a discharge appears necessary due to high water volumes caused by weather conditions.
One or more gate flaps 28 and in particular the middle gate flap 28 can be embodied as a displacement body 32. The displacement body can cause the water in this region to be more strongly dammed so that an effect is produced which is also known from the shipping sector, namely that where a displacer passes through the water, e.g. a pleasure craft, a higher stern wave piles up behind the displacer than at the sides. This means that the wave 9 can be manipulated locally.
It should be noted in this connection that the bottom 3 of the water body can be a natural bottom or an artificial bottom or else the bottom of the water body is a paved bottom 3 only in the vicinity of the device 1, for example made of concrete or the like. This does not exclude the possibility of the bottom of the water body being in natural form upstream and downstream of the device 1.
In this case, the ramp 4 is embodied so that a front control surface 33 transitions from the bottom 3 of the water body into the ramp and extends up to a top 34 of the ramp. The control surface 33 has a concave cross-section. From the top 34 of the ramp, the ramp 4 drops with the step 5 into the stilling basin and is also aligned with the step 5.
The control surface 33 can be embodied as flat inclined, concave, or in the form of a brachistochrone curve in order to ensure an optimized flow transition from the bottom 3 of the water body to the ramp 4.
To generate a wave in this embodiment, flat inclined ramps 4 or, in particular, ramps 4 with brachistochrone curves in profile can be used to transform the Froude number from <1 to >1. A brachistochrone curve accelerates the water faster than a flat inclined ramp, which means that a shorter section can be used to accelerate the water than is the case with a flat inclined ramp, especially with large height differences between the headwater and tailwater (the bottom 3 of the water body in front of the ramp and the stilling basin bottom 6).
Nevertheless, the ramp can also be offset a little forward in relation to step 5 and furthermore, the illustration is not to scale so that the ramp 4 can also be significantly larger overall and can also be significantly farther away from the gate 10. Instead of a spoiler-like design, as shown in
In the stilling basin 7, the flow body 15 is embodied of one piece with the stilling basin bottom 6, wherein the front flank 18 of the flow body 15 also has a gradient here, as a result of which a water flow flowing down from the wave strikes it essentially perpendicularly. A rear flank 35 of the flow body 15 is steeper and slopes down to the stilling basin bottom 6.
In
The resulting flow pattern is shown in
In another advantageous embodiment (
The length of the section 37 in the flow direction S is slightly shorter than the length of the gate 10 in the flow direction S from the front edge 24 of the gate base plate 22 to the rear edge 31 of the gate flap 28. Preferably, the section 37 starts upstream of the support columns 23 and ends a short distance downstream of the rear edge 31.
The positioning of the section 37 at the bottom 3 of the water body below the gate 10 can cause further acceleration in this region, particularly in conjunction with the gate flaps 28, so that water that is dammed up in front of the gate 10 can flow away more easily.
In yet another embodiment (
In a modification to the previous embodiments, the gate 10 in this case has a gate base plate 22 that extends parallel to the plateau 40 of the wall element 38 and in this respect does not significantly narrow the flow path or only narrows it with a bevel 44. The bevel 44 extends from the front edge 24 in the direction of the plateau.
In this case, the articulation 29 between the gate base plate 22 and the gate flaps 28 is situated behind the interrupting edge 42 in the flow direction S so that a rear edge 31 of the gate flap 28 is positioned in the vicinity of the concave rear wall 43 and can be pivoted toward the rear wall 43. This combines the effect of the gate flap 28 with a steep gradient.
To modulate the wave 9, particularly in the central region, a displacement mechanism 45 is positioned in front of the ramp 4 on the bottom 3 of the water body. This mechanism (
A swivel arm 48 is provided on the swivel shaft 47 at a distance from the support structure 46. The swivel arms 48 extend from the swivel shaft 47 to a displacement plate 49, which they are positioned on top of. The displacement plate 49 has an extension transverse to the flow direction S, which extends laterally beyond the support structure 46 and the swivel arms 48.
In this case, the displacement plate 49 can be embodied as approximately rectangular, with a rear edge 50 facing the support structure 46, two side edges 51, and a front edge 52. The front edge 52 here can extend the displacement plate toward the center of the displacement plate 49, tapering to a point. Below the displacement plate 49, a displacement body 53 is positioned on the displacement plate 49 and has an extension transverse to the flow direction that is smaller than that of the displacement plate and, in particular, extends from one swivel arm to the other on the underside.
The displacement body has side walls 54 spaced from the side edges 51 and a front wall 55 facing into the current, which can also extend in the middle to a projecting edge 56, similar to the prow of a ship. If the displacement plate 49 with the swivel arms 48 and the swivel shaft 47 is lowered to the bottom of the water body, it is positioned in the flow at an angle to the bottom of the water body, whereby it acts in its region like a gate flap or additional gate flap and leads to a partial elevation of the wave 9.
In
The advantage of the invention is that a very tall, easily controllable surfable wave is achieved with comparatively little equipment, which is also very easy to maintain.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102023116214.4 | Jun 2023 | DE | national |
