NO310138B1 - Water Ride Arrangement - Google Patents

Description

The present invention relates to a device for producing a flowing body of water on a surface without a container, where part of the surface is inclined, as stated in the introduction to patent claim 1.

By regulating the speed and depth of the flow in relation to the area and angles of the slope, a new flow dynamic is created which provides a rider-controlled water slide activity similar to the sport of surfing.

In the last 25 years, surfing and associated water riding activities (for example knee-boarding, body or boogie boarding, skim-boarding, surf-kayaking, inflatable riding and body surfing (hereafter collectively referred to as wave-riding)) have received an increasing popularity along the world's wave-prone coastlines. At the same time, in the 1980s there has been a tremendous growth of water recreation facilities for the family, i.e. water parks. Large pools with artificial waves have been an integral component of such water parks. Different types of wave pools have been developed. The most popular types are those that enable swimmers or people using air mattresses or swimming rings to float on the non-breaking waves generated by the wave machine.Although small breaking waves can be produced in this type of wave pool, it is not an ideal wave type for wave riding There are a few pools that produce large turbulent breaking waves that form from the deep to the shallow end of the pool. g enables white water wave (broken wave) riding, but broken wave riding is not preferred by the experts in the wave riding world. The type of wave that has the most appeal to a wave rider is a combination of an unbroken but rideable wave face with a "breaking"/"ends" curl or drop.

The ideal unbroken but rideable wave surface can be described as a smoothly sloping wall of water of at least one meter height with a surface of sufficient slope so that the gravitational force component causes the surfer to overcome friction and slide (e.g. surf) on it. The classic breaking wave can be described as a wave moving obliquely to a beach with a wave height of more than one meter with a part closest to the beach that is broken, while the part furthest from the beach has a smooth surface with a transition from smooth to broken portion of the wave that is continuous over a region spanning a few wave heights and with a transition region lasting more than 10 seconds. In a breaking wave, this transition area is of particular interest to wave riders. The transition area is where the wave rider performs optimal gliding (e.g. surfing) movements. The transition area is also where the wave surface reaches its maximum pitch angle.

As the wave rider's skills increase from beginner to advanced, he will seek challenge in different wave types. Beginners start on the "inside" with an already broken whitewater burn. These waves are the easiest to catch, but they offer little opportunity for surfing movements. The next step is to move to the "outside" just behind the broken zone. Here, a beginner will prefer an unbroken wave with just enough slope to "catch" the wave. When the wave breaks, the beginner will prefer a gently falling wave. The more advanced the wave rider becomes, the greater the desire for steeper waves, with the last wave type being progressive tubes or tunnels.

For several years, the inventor has been trying to mechanically mimic the ideal wave for wave riding that will provide a complete wave range for wave riding for beginners and advanced. Most of these attempts have been focused on the reproduction of moving progressive gravity waves that naturally occur at a beach. Unfortunately, these attempts have had limited success for wave riding. Issues associated with moving progressive wave technology include: safety, skill, cost, sizes and capacity. Reproducing moving progressive breaking waves requires a large pool of expensive wave generation equipment. The desire for larger wave sizes inevitably results in more dangerous conditions, such as deeper water and stronger currents. The approach to moving progressive waves usually requires a strenuous swim or paddle through breaking waves to place themselves in the catchment area of the unbroken wave. Catching a progressive breaking wave requires split-second reactions and a developed musculature. Riding a progressive breaking wave requires great skill in balancing the hydrodynamic lift forces associated with a planing body and the buoyancy forces associated with a displacing body. Progressive waves are therefore an attraction with a low capacity for water parks, i.e. one or two riders per wave. As a consequence of limited wave quality, different skills of the athletes, high costs, possible liability and a large ratio between surface area and rider capacity, wave pools specially designed to produce conventional moving progressive breaking waves have, with few exceptions, proven to be of little commercial use.

Le Mehaute (U.S. Patent 3,802,697) and the following three publications: (1) Hornung, H.G. and Killen, P., "A Stationary Oblique Breaking wave For Laboratory Testing Of Surfboards"", Journal of Fluid Mechanics (1976), Vo. 78, Part 3, pages 459-484; (2) P.D. Killen, "Model Studies Of A Wave Riding Facility", 7th Australasian Hydraulics and Fluid Mechanics Conference, Brisbane, (1980); and (3) P.D. Killen and R.J. Stalker, "A Facility For Wave Riding Research", Eighth Australasian Fluid Mechanics Conference, University of Newcastle, N.S.w. (1983), (all three papers will be referred to as "Killen") describes the generation of a unique group of progressive waves called a stationary wave. Stationary waves, unlike the previously mentioned traveling waves, are normally found in rivers where boulders lie on the bottom disturbs the flowing river water and forms a wave that moves upstream at an equal and opposite speed, so that it is stationary relative to the bottom.

The stationary breaking waves described by Le Mehaute and Killen avoid the "moving target" problem associated with moving progressive gravity waves. The consequence is that from a spectator's perspective on the beach, they are more predictable, easier to observe and easier to access. Although improved, the stationary breaking waves of Le Mehaute and Killen, when transferred to commercial water recreation facilities, still suffer from significant progressive wave problems. In particular, these problems include: disproportionate skill of the rider to catch and ride the wave, possibilities of drowning in deep water (since the water depth is greater than the height of the breaking wave) and large costs associated with generating the necessary water flow to generate the wave. In other words, both Le Mehaute and Killen use relatively deep amounts of water compared to what is found on a beach.

The method of wave generation at Le Mehaute and Killen involves an obstacle placed in a stream of water bounded by surrounding walls. The hydraulic state of the flow is described as supercritical flow going up along the surface of the obstacle, critical flow at the crest or end of the obstacle when the wave breaks (a surging "hydraulic jump"), and subcritical flow over the back of the obstacle. A submerged dividing flow surface splits the supercritical upstream part from the subcritical downstream part which flows over the backside of the respective obstacles. A result of this "critical flow breaking process" (i.e. where the Froude number is equal to one at this breaking point) is the ratio between water depth and wave size where the maximum achievable wave height is 4/5 parts of the water depth. The consequence of this with Killen and Le Mehaute, the larger the desired wave, the deeper the associated flow must be.

The disadvantages described above have enormous economic significance. Killen and Le Mehaute require pumps with enormous pumping capacity to produce a large wave. Furthermore, this state of deep flow requires a great deal of skill on the part of the rider.

For example, when a wave rider paddles to catch a wave in a deep water current (a deep water current is where the pressure disturbances due to the rider and his craft are not affected by proximity to the bottom), the craft will act primarily as a displacement hull held by buoyancy and transition to the primary a planing hull (reducing board friction) as a result of the hydrodynamic lift that occurs from paddling to riding a wave. The forces that appear when riding this wave are a combination of buoyancy and hydrodynamic lift. The faster the board goes, the more lift the mass holds for the rider and the less the buoyancy force. As a reaction to this lift, there is an increase in pressure directly under the board. This pressure disturbance is reduced at a distance from the board in the ratio of one to the square of the distance.

In an environment with deep water flow, by the time the pressure disturbance reaches the flow layer, it has already been amplified to such a low level that the bottom has a negligible effect on this pressure disturbance. There is therefore no reaction to be transferred to the rider. This lack of bottom reaction in a deep water current gives the rider no support. Lack of support results in the necessity of greater physical strength to paddle and to transfer the surfboard from a pre-training hull to a planing hull in order to catch the wave. Lack of support will also result in greater instability, requiring greater axiometric skill on the part of the wave rider.

Furthermore, a deep water current inevitably carries a greater risk of drowning. For example, a 60 cm high breaking wave will require a current of 2.77 meters per second in 75 cm's water depth. Not even an Olympic swimmer can avoid being pulled into such a current.

Frenzl ((U.S. Patent Nos. 3,598,402 (1971), 4,564,190 (1986) and 4,905,987 (1990)) describes water flow up a slope. In addition to the disadvantages previously described, the structure of Frenzl is described as the bottom of a container. The side walls of this container act to restrict the water flow in its upward path in the expectation of retaining maximum potential energy for subsequent recycling efficiency. However, it has been found that such side walls will propagate oblique waves which can disrupt the formation of supercritical flow and eliminate the possibility of breaking waves. That is, Frenzl's container fills with water and submerges any supercritical flow. The sidewalls of the container also provide difficult access for wave riding. Furthermore, Frenzl's device is designed for wave riding in equilibrium. The bulk of the wave riding maneuver, however, requires movement or oscillation around an equilibrium point through different zones of different weight in order to perform the relevant maneuvers.

As further examples of prior art, reference may be made to WO90/06790, FR-1539959 and WO83/04375. Of these shows both

W090/06790 (Lochtefeld) and FR-1539959 (Frenzl) water ride devices of conventional design where the flow of water up the inclined riding surface will be contained by a pair of side walls defining a primary enclosure or channel containing the water to be used and recycled by the water ride device nothing. If the water flow in these devices were turned off, each riding surface would at least be filled or flooded with water, as the water (or at least part of it) would be blocked off on the side surface of the side walls. This increases the difficulty of restarting water riding since special devices or procedures must be arranged to remove this collected or stagnant water from the riding surface in order to be able to achieve regular or constant operation again.

W083/04375 (Croul) describes another water ride concept where a lubricated water slide is used which is adapted to simulate a riding experience similar to surfing. The water slide comprises a shaped slope having various surface irregularities covered with a vinyl coated foam and incorporating an irrigation system adapted to lubricate the vinyl surface with a thin film of water. Croul thus does not describe a water-riding device which includes an inclined riding surface and a flow of water directed upwards on the inclined riding surface and which essentially adapts to it.

The present invention constitutes a significant improvement compared to prior art, and this is achieved by a device of the type mentioned at the outset, which is characterized by the features indicated in the characteristic of patent claim 1.

Advantageous embodiments of the invention appear from the independent patent claims.

In inclined flow environments, it will be extremely easy to form oblique waves because these waves propagate upstream, they have a downward component that achieves an increase in energy due to the change in slope in the downward direction. Since this increase in energy results in an increased amplitude as the oblique waves travel downstream, they will form a "gap" that not only affects the rider's maneuver, but also propagates and causes the entire flow to drown.

In order to eliminate these disadvantages, the present invention therefore produces a containerless slope which prevents the formation of slope waves. The sloping riding surface is designed without side restrictions which allow water to run off at low speed so that the main flow of water up the slope maintains or increases the desired speed. It can thereby be achieved that waves of riding quality and also different wave types are maintained. It should also be pointed out that in addition to countless designs of the present invention, the principles of the present invention can be achieved according to several other methods to avoid subcritical flow induced by boundary layers.

Another important feature of the present invention is that the preferred type of water flow over the containerless slope is a relatively thin flow layer, in contrast to the relatively deep water used in the known technique. A stratified flow is where the water depth is sufficiently small, such that the pressure disturbance caused by the rider and his vehicle, is affected by the riding surface via a reaction force, which effects on the rider and his vehicle are generally known as the "ground effect". This provides a more stable ride so that less skill is required to catch and ride the wave.

In the laminar flow situation, the fold is so close to a fixed boundary, i.e. the flow bed or riding surface, so that the pressure disturbances from the board do not have time to reduce before they come into contact with the fixed boundary. This results in the transmission of pressure disturbances through the liquid and directly to the bottom. This allows the bottom to act as a reaction wall against the mass of the rider's body and helps to support the rider due to the ground effect. Surface currents are therefore more stable than deep water currents. From a trained rider's point of view, the basic effect will mainly provide improved performance in the form of more responsive turns, increased speed and a smaller maneuvering radius which is a result of improved lift which enables a reduction of the vehicle's planing surface. Layer flows can also provide an adapted flow in that the flow generally follows the contours of the riding surface. This thereby enables a better control of the shape of the waves since they are adapted to the riding surface, while still achieving the special wave effects when insufficient velocity at the boundary layer allows flow separation from the contoured flow bed.

In this connection, it should be noted that with a layered flow up a containerless slope, no wave is required for the rider to be able to enjoy himself with a water attraction, constructed according to the principles of the present invention. All that is required is a slope of sufficient angle to allow the rider to slide down the upwardly directed layer flow. Furthermore, the rider himself can increase the frictional force so that the speed is reduced and can be sent back up the slope so that he can carry out more manoeuvres. Likewise, if desired, the rider can achieve equilibrium (eg, a stationary position with respect to the flow) by regulating their friction relative to the upward water flow.

Another feature of the present invention is that whenever a hydraulic jump occurs, there is no critical and subcritical flow over the top and back of the obstacle (i.e. "reservoirless slope"), and the fact is that the top or crest of the obstacle used according to until the invention is dry. In addition, the invention describes a separation streamline that not only defines the transition from supercritical to subcritical, but also divides the wet lower part of the surface from its dry upper part. The phenomenon of a separation streamline is not present in the prior art. The fact that the present invention has no correspondence between wave size and water depth is of great importance and a consequence of this is that the illusion of a large wave with preferably shallow currents can be created.

The principles of the present invention can be transferred to many different stationary wave conditions. For example, the degree of inclination of the inclined riding surface can be varied to a large extent to achieve different effects. The riding surface can also be inclined about the longitudinal axis or be provided with ramparts, shapes or different contours to produce waves of different shapes.

The riding surface can also be elongated, truncated, symmetrical, asymmetrical, flat or with a complex curvature. In addition, the depth or speed of the flow can be varied from one rider to another, or even provide a gradient to a single rider. All these mentioned parameters can of course be varied individually or simultaneously, together with other parameters within the protection scope of the invention.

In order to better understand the advantages of the invention described here, a more detailed explanation of various terms is given below. However, it should be noted that these explanations are in addition to the ordinary meaning of these terms and are not intended to be restrictive of them.

A deep water current is a current that has sufficient depth so that the pressure disturbances from the rider and his vessel are not particularly affected by the bottom.

A body of water is a volume of water where the water flow of the body is constantly changing and with a shape thereof, at least with a length, width and depth sufficient to allow water sliding maneuvers on it as limited or expanded by the respective type of flow, i.e. deep water or bed flow.

Water sliding maneuvers are those maneuvers that can be performed on a flowing body of water on a non-container slope and include riding across the surface of the water, riding horizontally or at an angle to the water flow, riding down a water flow on a sloping surface in the opposite direction of the flow moving up the slope , manipulating the planing body to cut into the surface of the water in order to perform an upward arcing turn, riding back up along the surface of the slope and cutting back and returning down and above the surface of the water and the like, such as "lip bashing, floaters, inverts, aerials , 360's, etc". The water-gliding maneuvers can be performed with the human body or on or with the help of a gliding or planing craft such as a surfboard, bodyboard, water ski, air mattress, swimming ring, kayak, jet-ski, windsurfing etc. In order to be able to perform the water-gliding maneuver, must the forward force component required to hold a rider (including any glider he rides) in a stable riding position and overcome the fluid friction due to the downward component of the gravitational force formed by the constraints of the fixed flow-forming surface is balanced primarily by torque transfer from the high-velocity upward flow of water on the formed surface. A rider's upward movement (with an excess of kinetic energy supplied by the rider or the craft) consists of the rider's frictional force relative to the upward water flow exceeding the downward gravitational component. In riding maneuvers that are not in equilibrium such as turns, slalom movements and oscillation between different heights on the "wave" surface are made possible by the interaction between the respective forces as described above and the utilization of the rider's kinetic energy.

The equilibrium zone is the part of an inclined riding surface on which a rider is in equilibrium on an upwardly sloping body of water flowing over it, so that the upward flow momentum transferred to the rider and his vehicle via hydrodynamic action is balanced by the downward gravitational component associated with the mass of the rider and the vehicle.

The above-1equilibrium area is the part of the riding surface adjacent to that which lies downstream (on the upper side) of the 1equilibrium zone where the slope is sufficiently steep for a rider to overcome the frictional forces associated with the upward water layer flow and slide down it.

The under-equilibrium area is the part of the riding surface adjacent to that which lies upstream (below) the equilibrium zone where the slope has a steepness that is too small for the rider to overcome the frictional forces associated with the upward water layer flow and stand in equilibrium on this. Due to the influence of the liquid, the rider will possibly be moved in the direction of the flow back up the slope.

The Froude number is a mathematical expression that describes the relationship between the flow velocity and the phase velocity of the longest possible wave that can be present at a given depth without being destroyed by refraction. The Froude number equals the flow velocity divided by the square root of the product of the gravitational acceleration and the water depth. The Froude number squared is the ratio between the flow's kinetic energy and its potential energy, i.e. the square of the Froude number corresponds to the flow velocity squared divided by the product of the gravitational acceleration and the water depth.

Subcritical flow can generally be described as a slow/

thick stream of water. In particular, subcritical flows have a Froude number less than 1, and the kinetic energy of the flow is less than its gravitational potential energy. If a stationary wave is in a subcritical flow, it will be a non-breaking stationary wave. IN

the form of the equation is a flow subcritical when v < \/gd, where v = the flow velocity in ft/sec., g = the acceleration due to gravity ft/sec.<2>, d = the depth (in feet) in the body of water.

Critical flow is manifested by breaking waves. Critical flow is when the flow's kinetic energy and its gravitational potential energy are equal. Critical flow has the characteristic physical property of a hydraulic jump. Due to the unsteady nature of wave breaking, it is difficult to maintain critical flow in an absolute steady state in a moving water flow, given that the speed of the wave must match the speed of the current to remain stationary. This is a difficult balance sheet number. These exact conditions correspond to each other only at a point for a particular flow rate and depth. Critical flows have a Froude number equal to one. In equation form, a flow is critical when v = \/gd, where v = the flow velocity, g = the acceleration due to gravity ft/sec.<2>, d = the depth of the water layer.

Supercritical flow can generally be described as a thin/fast flow. In particular, supercritical flows have a Froude number greater than 1, and the kinetic energy of the flow is greater than its gravitational potential energy. In supercritical flow, there are no standing waves. The reason for the lack of waves is that neither breaking nor non-breaking waves can keep up with the current speed because the maximum possible speed for any wave is the square root of the product of the gravitational acceleration times the water depth. Any wave that does form is quickly carried downstream. In equation form, a flow is supercritical when v > \/gd, where v = flow velocity in ft/sec., g = acceleration due to gravity ft/sec.<2>, d = depth (in feet) of the water layer.

The hydraulic jump is the point at which waves break into the fastest waves that can exist at a given water depth. The hydraulic jump itself is actually the breaking point of this wave. The refraction phenomenon is the result of a local energy convergence. Any waves that may appear upstream of the hydraulic jump in the supercritical region are unable to keep up with the flow and will therefore be carried downstream until they meet the area where the hydraulic jump occurs, now the flow is suddenly thicker and now the waves can suddenly move themselves faster. At the same time, the downstream waves, which can move faster, can move upstream and meet at the hydraulic jump. The wave convergence at this flux point thereby leads to wave breaking. With respect to energy, the hydraulic jump is an energy transition point where the wave current energy changes from kinetic to potential energy. A hydraulic jump occurs when the Froude number is 1.

A stationary wave is the progressive wave that moves upstream and has a phase velocity that exactly matches the flow velocity, thereby allowing the wave to appear stationary.

White water occurs due to wave breaking at the leading edge of the hydraulic jump, where the flow transitions from critical to subcritical. In the flow environment, turbulence residues and air bubbles from the wave breaking will be carried downstream through the subcritical area and spread within a distance of 7 jump heights behind the hydraulic jump.

The separation is the point of zero wall friction where the bed flow is broken away from the wall to the slope or another form based on this.

Flow separation results from different losses of kinetic energy through the depth of the bed flow. As the bed flow continues up the slope, it begins to slow down, and the kinetic energy will transfer to potential or gravitational energy. The part of the bed flow that is directly close to the wall of the slope (the boundary layers) will also have a further loss of kinetic energy due to the wall friction. These additional frictional losses cause the boundary layer to lose kinetic energy and remain in a state of zero wall friction, while the outer part of the layer flow still has residual kinetic energy. At this point, the outer part of the stratified flow will break away from the slope wall (separation) and continue in a ballistic trajectory where the remaining energy forms either downflow or a swing back over the rising flow.

The boundary layer is an area of impeded flow directly near the wall due to friction.

The separation flow line is the path taken by the outer part of the layer flow which does not remain at rest due to the influence of frictional effects, but breaks away from the wall surface at the point of separation.

Flow division is the lateral division of flows with different hydraulic states.

A division streamline is the streamline that defines the position of the flow division. The surface over which the flows are divided laterally between supercritical and critical hydraulic conditions.

A tidal wave is a progressive hydraulic jump that can appear stationary in a current when the tidal wave speed is equal and opposite to that of the current.

A velocity gradient is a change in velocity over a certain distance.

A pressure gradient is a pressure change over a certain distance.

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Adaptive flows occur when the angle of incidence to the full depth of the body of water (at a particular point relative to the sloping flow-forming surface over which it flows) is essentially tangential to this surface. The sequence is that water flowing on a sloping surface can adapt to gradual changes in slope, such as curves, without the flow separating. As a consequence of flow matching, the downstream end of an inclined surface will always physically direct the flow in a direction aligned with the downstream end face. The change of direction in an adapted current can exceed 180°.

The invention not only tries to solve these previously mentioned problems with existing unbroken waves and breaking wave theories, but also tries to bring about entirely new possibilities in water-riding dynamics not described in the prior art. In addition to a sheet flow of water on a containerless upward sloping surface, by changing these combinations by adjustments of water depth, water velocity, water direction, surface area, surface shape (contour) and surface height, waves can be formed that simulate a whitewater tidal wave, an unbroken but sliding wave surface, a breaking wave and a breaking tunnel wave. The changes can also create a fluid environment with distinctive riding capabilities that are far superior to those typically available in naturally occurring progressive waves, such as greater lift and speed. Furthermore, functional structural changes of a containerless slope will allow the creation of a number of new water-riding attractions that have hitherto been unknown in nature or for the water recreation industry.

The reason the present invention can achieve these purposes is that it does not copy naturally breaking progressive waves, but instead forms "flowforms" from high-velocity sheet currents over a suitably designed

surface. The main part of the flow patterns formed by the present invention are technically not waves. They may appear as gravity waves breaking obliquely against a beach, but these flow forms are specific hydrodynamic phenomena caused by four dynamic effects: (1) the unique surface design of the invention, (2) the flow path of the water in relation to the flow-forming surface, (3) flow separation from this surface and (4) changes in hydraulic state of the flow (i.e., supercritical, critical, or subcritical) at this surface.

Accordingly, the following advantages are achieved with the present invention: (a) To provide an inclined tankless surface on which a steady flow of water can produce a body of water simulating a type of wave preferred by surfers in the first stage of wave riding, i.e. an unbroken but rideable wave surface. This body of water has the appearance of a stationary wave in a subcritical flow, but is actually formed by supercritical water flowing over the containerless surface. Advantages of a tankless surface design include: (1) improved starting characteristics via side venting of transient wave motion; (2) a smooth water flow in that unwanted oblique waves induced by the enveloping are avoided, e.g. channel walls; (3) quick and safe access for the rider without canal wall obstructions; (4) elimination of service interruptions associated with flooding; (5) elimination of pump and valve equipment necessary for flow in a container; (6) elimination of costly fast open/close valves required for immediate start-up of supercritical flow; (7) elimination of complex and expensive control equipment required for coordinated valve opening/closing and pump on/off operation; and (8) increased ride capacity due to an open flow architecture.

(b) To produce a sloping containerless surface on which a steady flow of water can produce a body of water simulating a

wave type that is attractive to first-time wave riders, i.e. a broken whitewater wave. The whitewater wave effect results from supercritical flow moving up the slope which, due to a hydraulic jump over the slope, produces a two-dimensional stationary breaking wave that simulates the whitewater wave in the absence of flow over the backside of the slope. The containerless surface allows the water to be ventilated laterally and avoid supercritical submerged flow. (c) To introduce a cross-current velocity gradient to a water current moving up a containerless surface with a planar crest line which then produces a body of water simulating a wave type attractive to novice surfers, i.e. a flowing wave with unbroken shoulders. This rushing sea-like effect is the result of the current having two coexisting hydraulic states, i.e. a higher velocity supercritical flow over the top of the wave crest and a nearby lower velocity supercritical flow that does not reach the wave crest due to insufficient kinetic energy. This low-energy supercritical flow will slow down to a critical state and form a hydraulic jump below the wave crest with an associated subcritical flow of turbulent water appearing adjacent to the supercritical flow. If this nearby flow were subcritical, it would merge with the supercritical flow in the form of an oblique hydraulic jump that accompanies the flow. The containerless surface allows ventilation of a stream of white water and thereby prevents complete submersion of the supercritical flow. (d) To controllably form a cross-flow velocity gradient and simulate the previously described unbroken shoulder flowing wave, either by means of an advantageously designed pump device or nozzle device. (e) To produce an asymmetrically elongated containerless surface on which a uniform velocity of flow forms a body of water simulating a wave type preferred by novice wave riders, i.e. a flowing wave with an unbroken shoulder. The asymmetrically elongated reservoirless surface forms a downstream ridge with increasing slope. A flowing body of water with sufficient kinetic energy to supercritically overflow the lower side, but with insufficient energy to overflow the high side, will exhibit flow splitting, i.e. the flow to the high side will transition to subcritical and is shown by a hydraulic jump and associated white water. A natural consequence of the tankless surface's asymmetry is its ability to solve the transient wave motion problems associated with ride initiation and rider-induced flow breakdown on the upsloping flow surface, i.e. formation of asymmetrically sloped flow-shaping surface provides a wave crest of maximum height with reduced lift that facilitates self-clearing of unwanted transient wave movements and excess white water. (f) Producing an extended surface consisting of a substantially horizontal flat surface (subequilibrium region) which extends the aforementioned containerless inclined surface in the upstream direction. The extending surface allows the rider to maximize his forward speed using his own effort, so-called "pump-turning", which will be described in more detail as the acceleration process. The acceleration process allows the rider to gain additional speed in a similar way to a child on a swing producing additional speed and height. Given that the purpose of surfing is for the rider to be able to enjoy the feeling and power of increased speed which is the result of cyclic transitions between the overequilibrium area and the underequilibrium area in relation to an equilibrium position, the extended surface will provide a significant advantage. A natural consequence of the improvement of the extended surface is to

tilting the extended surface in a direction perpendicular to the extension, creating a gravity-induced lateral component that allows the rider to move in the direction of the fall. Such a movement has the further advantage of increasing capacity by increasing the rider's speed through the device and improved safety and easier maintenance by improved drainage of cloudy water from the riding surface by shutting off the layer flow.

(g) To produce a flat to sloped three-dimensional shaped container surface that produces a body of water that simulates a wave type that appeals to intermediate to expert wave riders, i.e. an unbroken but rideable shoulder with a tunnel wave of different sizes, depending on the flow speed. That is to say, the essentially two-dimensional riding surface can be provided with a contour shape that forms a three-dimensional flow layer that gives unique wave properties. The tunnel portion of this body of water has a mouth and an enclosed tunnel that extends some distance into the interior of the front face of the wave form, in which the wave rider attempts to ride. This tunnel section has the appearance of a crashing progressive wave that occurs on natural beaches. However, it is the result of a contour-induced supercritical flow separation. An advantage of flow separation is that a satisfactorily designed beakerless slope can generate tunnel waves of increasing size (i.e. tunnel diameter) in proportion to an increase in the speed of the water flowing over it, without simultaneously requiring an increase in the water depth or a change in the shape or size of the containerless slope. When this supercritical tunnel collapses at the tip of the slope, the containerless surface will allow venting of the turbulent water, thereby avoiding supercritical submergence of the flow. Flow separation also allows tunnel wave formation on a containerless sloping forming surface that is not curved back on itself and may actually be significantly less than vertical. One

less than vertical flow-forming surface with a containerless scraper is easier to design and construct, since complicated design and support structure problems are avoided. In addition, this containerless surface will allow tunnel wave formation in both deep water and laminar flow conditions. (h) To produce a more than vertical extension of a three-dimensionally designed tankless surface that produces a body of water simulating a wave type that appeals to intermediate to expert wave riders, i.e. a tunnel wave with an unbroken but rideable shoulder. Unlike the tunnel wave as described in point (g) above, a more than vertical extension will allow a flow tunnel to form at high speed without separation. This containerless surface preferably allows wave formation in situations where the greatest flow rate is significantly higher than the vertical height of the wave-forming device. (i) Producing a flow of water on the previously described shaped containerless surfaces which (by means of a progressive increase in flow rate) transfers this flow from a simulated stationary whitewater wave along the entire forming device to a simulated flowing wave with an unbroken shoulder to the final tunnel wave with an unbroken but rideable shoulder. This method is hereinafter referred to as the "wavelet transform process". The wave transformation process has the advantage that it gives the rider or an operator the opportunity to produce a variety of wave types, for example white water waves, unbroken, flowing or tunnel on a single adequately designed device within a relatively short period of time.

(j) Producing longitudinal movement over a sloping containerless surface of a body of water with sufficient headroom (hereafter referred to as a "slope") to permit a rider to adjust his speed longitudinally

with the speed of the cut and perform a water slide maneuver on this. This movable cut will give the practical advantage of increasing the rider capacity and reducing the total energy requirements for flow over the entire sloping tankless surface. This embodiment would also give the rider or operator the added benefit of being able to move to an end point that is different from the start point. Furthermore, by changing the contour of the containerless surface or the direction or speed of the flow, different wave conditions (eg flowing, pipe, etc.) can be produced during the ride.

(k) To produce a flow source that is free of oblique waves. In one embodiment of the invention, the positions of the flow source, for example the opening, the nozzle or the overflow, are at an elevation connected to an inclined surface which changes to a horizontal surface and which then changes to an inclined surface. (1) To produce a device that will enable the rider to perform water sliding maneuvers in a format that has hitherto been unavailable, apart from corresponding participation in separate and specific sports such as the use of skateboards or snowboards, such as half-pipe riding. The present invention produces a containerless surface for forming a body of water with a stable shape and a sloping surface on this, mainly designed as a longitudinally oriented half-pipe. This shape is hereafter referred to as "fluid half-pipe". A natural improvement to the fluid half-pipe is to produce a device that allows an increased capacity by increasing the depth of the fluid half-pipe in its longitudinal direction. This increase in depth will give the further advantage that the rider will move in the direction of the fall and simplify his trajectory.

(m) To produce a flexible containerless surface capable of generating disturbances or peristaltic motion by means of a motion-generating auxiliary device. Disturbances of the containerless surface will change the flow pressure gradients and thereby produce stationary but changing wave characteristics, for example flowing waves, tunnel waves or also different types of tunnel waves. Sequential undulating or peristaltic movement of flexible containerless surfaces will produce a new moving wave with varying wave characteristics. Such a device also has the advantage that the participant can move to an end point that is different from the starting point with increased capacity.

(n) To produce a water flow for all containerless surfaces as described above, either in deep water or bed-flow format. Deep water currents on a containerless surface will simulate ocean-like surfing conditions and enable a controlled meeting place for training, competitions and general recreation. Stratified flows on tankless surfaces will increase safety due to reduced water depth, reduced water maintenance due to reduction of the volume of water being treated, reduced energy costs by minimizing the amount of pumped water, reducing the required skill level of participants as a result of easy access and improved riding stability on due to the "bottom effects" and improved riding performance (i.e. lift and speed) due to the bottom effects.

(o) Employing a unique distinct wave generation process, i.e. flow separation that creates the illusion of a large deep water wave using advantageous shallow currents.

(p) To connect a sloped containerless surface to other attractions, such as a "lazy river", "whirlpool", regular rapid whitewater rides, conventional wave pools or "activity pools". Such connections will enable a rider to be able to enable others attractive

attractions known to those skilled in the art. Such a combination has additional benefits of increased rider capacity and utilization of the kinetic energy of motion of the water emerging from the sloping tankless surface and thereby an additional capacity, for example by leading the riders around the length of a connected "lazy river".

(q) To provide a fence that allows ventilation of flowing white water, avoids the formation of oblique waves and allows control of rider entry and exit from all sides of a tankless slope. Such a fence can also be used to act as a separation mechanism that forms lanes that prevent rider contact and improve safety.

(r) Producing a riding craft in connection with a containerless surface and which is positioned for hydroplaning in the stream. A movable anchorage can act as a transfer mechanism from a starting position on the outside of the flow to a planing position in the flow. Thereby, the mooring can either continue to act as a transfer mechanism to transport a rider controllably to the end point of the ride on the outside of the stream or the anchor can be released so that the rider can control his own path. a movable anchorage will provide the practical benefit of simplifying rider entry and improving rider capacity.

(s) To provide a sliding entry mechanism that safely and rapidly guides participants into a sloped containerless surface flow.

(t) To supply a reservoirless sloping surface with a dam or reservoir as a method of distributing excess potential energy from a body of water of greater height flowing to a lower level. Such a method can preferably be used as a safe controlled drain and prevent downstream erosion.

Other advantages of the present invention will be apparent from the following detailed description with reference to the accompanying drawings. Figure 1 shows the containerless slope according to the present invention. Figure 2 shows a simple tankless slope during operation. Figure 3a shows a containerless slope in combination with a water recycling system. Figure 3b shows a tankless slope where the drain is used to drive a winding river or a whirlpool.

Figure 3c shows the device in Figure 3b seen from the side.

Figure 4a shows a tankless slope that does not require a splash pool seen from the front.

Figure 4b shows the device in cross section.

Figure 4c shows the device in perspective.

Figure 5 shows a simulated whitewater wave on a slope without a container. Figure 6 shows a simulated flowing wave with an unbroken shoulder on a containerless slope. Figure 7 shows an asymmetric nozzle design that can produce a current that produces a hydrostatic rocking. Figure 8 shows the asymmetric nozzle of Figure 7 in operation when simulating a flowing wave with an unbroken shoulder. Figure 9 shows the simulation of a flowing wave from a uniform orifice with different internal core flow pressures. Figure 10 shows an asymmetrically extended containerless slope that simulates a flowing wave with an unbroken shoulder. Figures lia, 11b and lic are three profile drawings showing a self-clearing, sloping surface at different times. Figures 12a and 12a', 12b and 12b', 12c and 12c' show in three planes/profiles the effect of different heads that are used to increase the throughput capacity. Figure 13 shows an extended containerless slope with a subequilibrium area.

Figure 13b shows a cross-section of Figure 13a.

Figure 14 shows a rider accelerating during a turn as a result of an extended canisterless slope. Figure 15a shows a sloping tankless slope for increased capacity. Figure 15b shows a sloping tankless slope during operation. Figure 16a shows a topographic contour of a preferred embodiment of a three-dimensional tankless sloping surface with contours that produce a body of water simulating the types of waves attractive to intermediate to advanced wave riders, i.e. a tunnel wave with an unbroken but rideable shoulder.

Figure 16b shows Figure 16a in profile.

Figure 16c shows the streamline trajectories on a containerless slope simulating a tunnel wave with an unbroken but rideable shoulder. Figure 16d shows the topography of a containerless slope with minimal deflection that still allows the formation of tunnel waves. Figure 17 shows a cross-section of a containerless slope that will produce adapted tunnel waves. Figures 18a, 18b, 18c indicate in three profiles a containerless slope undergoing the wave transformation process. Figures 18d, 18e, 18f indicate the wavelet transformation process with riders. Figures 19a, 19b, 19c show a moving "shear" on a containerless slope. Figure 20 shows several moving "shards" on a containerless slope simulating a variety of wave types. Figure 21 shows a flexible riding surface on a containerless slope which can produce a peristaltic movement. Figure 22 shows the appropriate position of a water current source to minimize the formation of shear waves. Figure 23 shows in profile a new design for water sports fluid half pipe.

Figure 24a shows a section of a typical fluid half pipe.

Figure 24b shows a section of a fluid sea pipe with a modified flow-shaping bottom that increases the capacity and the bypass. Figure 25 shows in prop file an improvement of the fluid half pipe which gives an increased throughput capacity. Figure 26 shows a sliding system for a containerless slope. Figure 27 shows a mooring system for a containerless slope. Figure 28 shows a riding craft attached by mooring lines to a pin attached to the riding surface.

Figure 29 shows a flow fence.

Figure 30 shows a tankless slope connected to the outlet from a pond. Figure 31 shows several interconnected containerless slopes with half pipes. Figure 32 shows a tankless slope with an overflow shoulder that supplies water to a connected whitewater river and whirlpool. Figure 1 shows an embodiment of a containerless slope 1 according to the invention. Planar section lines in Figure 1 are shown only to indicate the general three-dimensional shape and are therefore not illustrative of a particular frame, plan or profile section. It should be noted that a number of dimensions and designs for a containerless slope are consistent with the principles of the present invention. These principles should therefore not be considered limiting to any of the particular designs shown in the drawings or described herein.

The containerless slope 1 comprises a support structure 2 below the surface and the riding surface 3 which is delimited by a downstream hill edge (line) 4, an upstream edge 5 and side edges 6a and 6b. The riding surface 3 can be a canvas over the support structure 2 or it can be integrated with this as long as it is sufficiently smooth. If it is a cloth, the riding surface 3 can be made of any of several known materials, for example plastic, foam, thin-skinned concrete, formed metal, treated wood, fibreglass, chipboard, reinforced cloth, air-, foam- or water-filled plastic or textile bladders or any such material which is sufficiently smooth to minimize the loss of function and which will withstand the surface loads to which they are subjected.

The carrier structure 2 can be sand/gravel/stone; bundle and beam; compactly filled; tie rod; or any other known method of attaching and holding the riding surface 3 with the flowing water and the riders on it. The inclined shape of the riding surface 3 need not be limited to the inclined plane as shown in figure 1. The riding surface 3 can have a gradually varying curvature to form a smooth water flow. For example, the riding surface 3 can have an upward-facing concavity in the longitudinal direction parallel to the direction of water flow or a longitudinal section consisting of an upward-facing concavity that transitions to an upward-facing convexity or a combination of straight, concave and convex longitudinal sections. Such curved surfaces are shown in the subsequent figures.

Although many different shapes are possible, one element is constant in all embodiments of the containerless slope, i.e. there must be a sloped portion of sufficient length, width and angle of inclination so that the riders can design water-sliding manoeuvres. The smallest angle is approx. 7° from the horizontal plane. Steeper lean angles (with portions of curvature exceeding 90° vertical) can provide more advanced ride characteristics and flow phenomena, which will be discussed later. At a minimum length (from upstream edge 5 to downstream ash edge 4) and width (from side edge 6a to side edge 6b) of the tankless slope 1 must be greater than the respective length and width of the intended riding vehicle or body, so that water can drain from the riding surface 3. The maximum dimensions of the containerless slope 1 can have a large dimension range which depends more on external factors, for example space limitations, economy, water flow availability etc, than special limitations of the river structure.

In one case, the tankless slope with an angle of 20 degrees with respect to the horizontal plane was found to be suitable, to achieve the purpose of the present invention when a stream of water has a depth of 7.6 cm and a flow rate of 81.3 cm per minute. minute. The length and width of this slope was approx. 6.1 by 12.2 metres. In this case, the plant was located so that the discharge from the tankless slope formed a river and the height of the slope was 1.8 m on one side and 7.6 m on the other side. In addition, as described below in more detail, the water flowing around, over and off the containerless slope 1 was used for other water attractions. To achieve a flow with the specified speed over the slope, a water volume of 378.5 m<3> per minute found to be suitable, where the operating height of the pressure head was 5.03 m above the upstream edge of the slope 5.

Figure 2 shows the containerless slope 1 in Figure 1 during operation. The operation of this device requires a suitable flow source 7 (eg pump, fast moving stream or elevated pond/reservoir) which forms a supercritical bed flow of water 8, mainly in a single flow direction 9 (as shown by arrows) over the riding surface 3 ( whose side edges 6 and downstream edge 4 are shown with dashed lines) to form a sloping body of water on which a rider 10 performs water gliding maneuvers.

The rider 10 controls his position on the supercritical water flow 8 by balancing the forces, for example gravity, friction, hydrodynamic lift and drift and self-induced kinetic motion. The rider 10 utilizes the force of gravity and slides down the upward current by maximizing the planing properties of his craft and least friction by taking his legs and arms up from the water current. In the same way, the rider 10 can reverse the process and move upwards with the current by positioning the craft so that the planing decreases and by putting hands and feet into the current to increase friction. Non-equilibrium maneuvers such as turns, slalom movements and oscillation between different heights on the "wave-like" surface are made possible by the interaction of respective forces as described above and the application of rider kinetic energy.

There is no maximum depth for the supercritical flow 8, although shallow flows with a practical minimum depth of approx. 2 cm. The preferred relationship between flow depth and flow velocity can be expressed by means of a preferred Froude number. A practical range of Froude numbers for the tankless slope 1 is from 2 to 75, and the preferred range is between 4 and 25. Flows with Froude numbers greater than 1 and less than 2 are subject to contamination from pulsating motions, known as "roll -waves" which are actually spirals instead of waves. Stratified flows are preferred because circular flows on a tankless slope 1 will : (a) increase safety by avoiding the risk of drowning (one can easily walk or stand in a thin stratified flow), (b) reduce water maintenance due to the reduction of the volume of water that must processed, (c) reduce energy costs due to minimal amount of pumped water, (d) reduce the required skill level of participants as a result of easy access and improved riding stability due to "bottom effects"; and (e) improved riding performance (i.e., lift and speed) due to bottoming effects. Although shallow water currents are preferred, it is recognized that in certain conditions deeper water is necessary, for example 1 competitions where ocean-like surfing conditions are required or training or instruction in deep water.

A particular point is how the containerless slope 1 will allow the drainage of water 11 (as shown by downward curved lines with dashed ends), flowing from the side edges 6 and over the downstream ridge 4. As mentioned above, the "containerless" feature of the present invention important to achieve the desired sheet current property. Essentially, the lack of sidewalls of the container will allow an unrestricted flow of water up the inclined riding surface 3. So long as the flow lines of the water are continuous and substantially parallel to each other and to the side edges 6a and 6b of the riding surface 3, the integrity (i.e., the velocity and flow characteristics at smooth surface) to the bed flow. A flow that has no restrictions laterally will preferably avoid the effects of the boundary layer laterally and allow water runoff to the side, so that a smooth flow and an unaffected speed are maintained over the entire water layer. Furthermore, as described above, the principles of the present invention also apply to a sloping surface with different designs which do not necessarily have parallel sides 6a and 6b. In contrast, a container side wall will form a boundary layer effect which increases the static pressure of the water in the area by the side wall, so that the speed of the layer flow decreases and results in a disturbed surface flow. With a container or sidewall, such boundary layer effects and disturbances are unavoidable due to frictional forces and the resulting propagation of oblique waves, both of which make it difficult to maintain the parallel and continuous flow lines. A tankless slope with a single side wall may work for the purpose of the present invention, but due to the formation of undesirable oblique waves, this is only a preferred structure when an inclined hydraulic jump is desired to accompany an upward supercritical flow .

In addition, the propagation of oblique waves and other turbulent flows is eliminated due to the flow structure where a low static pressure is maintained along the lateral edges of the laminar flow. On the other hand, it should be noted that the disadvantages of boundary layer effects are greatly reduced when the layer flow is on a downward sloping surface. The reason for this is that the turbulence will to a small extent be propagated upstream against the gravitational force. Furthermore, any surface disturbance that may form is likely to be carried downstream by the greater kinetic energy of the main water flow, compared to the turbulent flow's ethical energy, and this kinetic energy is the result of the cavitation component of the downward flow.

By extending the riding surface 3, increasing or decreasing its height, adding additional surface area, changing the contour, adding horizontal and inclined surfaces and/or by changing the direction, speed or thickness of the supercritical water flow 8, the various laminar flow attractions described can be achieved.

As shown in Figures 1 and 2, no pool or water reservoir is required for the containerless slope 1. However, when water recycling is desired, Figure 3a shows a containerless slope 1, placed with the riding surface 3 above a lower collection basin 12 which enables water collection and reuse. The lower collection basin 12 is positioned to receive waste water 11 that flows over the side edges 6a and 6b to the riding surface 3. In addition, a similar collection basin can be placed at the opposite end of the riding surface 3 as shown in Figure 3a, to collect waste water on this side . The pump 13a transports static water 14a from the lower collection basin 12 through the pipe 15a to a reservoir 16 with an operating head positioned higher than the height of the downstream ash edge 4. Current head differences will vary, depending on the total friction losses associated with the riding surface 3, boundary layer effects and rider induced turbulence. A preferred minimum head difference is 25$ higher than the height of the downstream ridge 4 .

The nozzle 17 connected to the reservoir 16 allows the necessary supercritical flow 18 to move in the direction 9 on the tankless slope 1. However, to ensure a non-flooded (non-turbulent operation) water level 18 in the lower catch basin 12 should be equal to or lower than the lowest height of the riding surface 3. As an additional energy-conserving measure to minimize pumping costs, a separate upper collection basin 19 (or a series of basins, not shown) may be used to utilize the captured potential energy of the wastewater 11. The pump 13b transports static water 14b from the upper collection basin 19 through the pipe 15b to the reservoir 16. The depth and width of the lower collection basin 12 and the upper collection basin 19 must be sufficiently sized to hold sufficient water to be able to start the system and provide the rider 10 with an area of suitable large size to be able to fall into, in case you fall from the riding surface 3. A st ige 20 makes it easy to get out of the lower collection basin 12 and the upper collection basin 19.

An axiomatic condition for tankless flow operation is that the water flows down the edges of the slope 1. To maximize energy efficiency, the recreational experience and provide an improved user capacity, Figure 3b shows a preferred location of a tankless slope 1 to a nearby circulation pool or channel . Tangential surface orientation enables the kinetic energy of the drained water to effectively transfer its momentum and provide power to an associated eddy basin or meandering river course. A meandering river makes up what is known in the area as a "lazy river". A "lazy river" is a horizontal circular pool of water with a width of approx. 2-10 m and a depth of 0.5 - 1.5 m and a length of 100 - 1000 m, which moves at 1 to 2 m/sec. The purpose of the "lazy river" is to create a slow-flowing river for floating participants who have a high rider capacity. Common "lazy rivers" are powered by pumps that feed water from a variety of manifolds located at the bottom or sides.

In contrast, in Figures 3b and 3c, a meandering river course 40 is shown where the cost of manifolds is avoided by using waste water 11 emerging from the container run slope 1 which acts to carry the water in the meandering river course 40. Large waste streams from the containerless slope 1 can result in strong and varied flow conditions that are very attractive to river riders. The currents can range from negative eddy currents to 8+ meters per second. Furthermore, the horizontal orientation (i.e. essentially even height to the river current) may allow the river riders to float in an infinite loop.

Other advantages of the embodiment of Figure 3b is the possibility of forming progressive or moving waves in the river 40. Such waves, having the same characteristics as natural waves found in tidal currents up a river, can be generated by pulsating or cycling the current coming from the nozzle 17, so that a wave movement is formed in the flow. Under suitable conditions, this wave can travel across the entire "lazy river" 40.

In order to achieve the unique synergistic combination of tankless slope 1 and a functional curved river course 40, a suitable placement of the river course 40 with tankless slope 1 vis-a-vis water drain 11, pump inlet 80 and pump outlet 81 is required. Maximum power with minimal energy lost to a hydraulic jump 24 at the convergence of the wastewater 11 and water in the vortex basin 50 or the meandering river 40 is a function of two components: (1) introduction of the wastewater 11 at the surface of the water in the vortex basin 50 or the meandering river 40 and ( 2) introduction of waste water 11 as a tangent to the direction of flow in the whirlpool 50 or the meandering river course 40. In order to achieve a continuous circulation of riders in a meandering river course 40, an open channel with a regular "lazy river" design and a substantially uniform water level is required . In order to obtain a maximum effect of the pump suction to aid in river circulation, the pump inlet 80 for the pump station 82 should be located upstream and near the confluence of the waste water 11 and the longest stretch of undriven water in the meandering river course 40 (for example, where the speed of the flow in the river is at a minimum). For safety reasons, a floor/side wall 83 (see Figure 3c) separates the river course 40 from the pump inlet 80. The pump station 82 lifts the water into the reservoir 16 which supplies water for the operation of the tankless slope 1.

The wastewater 11 can also power a horizontal whirlpool 50. The whirlpool 50 is a circular pool with preferred dimensions of 10 to 70 meters in diameter with a depth of 0.5 to 1.5 meters and which swirls in a circular manner at a speed of 1 to 10 meters per . second. The height of the whirlpool 50 can be equal to or just below the top or the downstream edge of the containerless slope 1. As shown, the height of the whirlpool 50 is above the height of the river course 40 in order to provide an increased speed when the water from the whirlpool mixes with the pupil course 40 at the hydraulic jump 24. An appropriately sized whirlpool 80 may also be used instead of a flume or vice versa.

A curved river course 40 or whirlpool 50b can also be placed at the upper end of the pump outlet 81, as shown in Figure 3c. This location will be able to make use of the pump head speed to drive the flow circulation. In addition to effectively using the available energy, such a location will also help that the reservoir 16 can act as a settling basin and thereby provide a smoother flow from the nozzle 70. In this case, the height of the vortex basin 50 is higher than the river course 40 and can be on the same height or below (or even above as shown in Figure 3c) the height of the water in the reservoir 16. Figures 4a, 4b and 4c show a preferred embodiment of a tankless slope that does not use a pool or current for the rider to be caught up. Figure 4a shows a containerless slope 1 extended from the previously described limits, i.e. downstream the ridge 4 and the side edges 6a and 6b (shown by dashed lines in Figure 4a) with downwardly sloping transition surfaces 21a, 21b and 21c. The downward sloping transition rafts 21 adjoin the riding surface 3 and the surface carrier 2 were preferably made of the same material. Figure 4cx (front view) shows a containerless slope 1, extended by downward sloping transition surfaces 21 during operation. A supercritical flow 8 comes from a flow source 7 and moves in direction 9, forming a body of water, on which a rider 10a performs a water slide maneuver. The rider 10b completes his final maneuver and slides over the downward sloping transition surface 21b and towards the termination/exit area. In this exit area, the waste water 11 flows through a floor grate 22, on which the rider 10c can easily stand and walk away. The floor grating 22 is arranged with and acts as a boundary for the downward sloping transition surface 21 and comprises an anti-slip grid or panel surface perforated with small drainage holes for the waste water 11 and which is undercut to be able to hold the rider. As shown in cross-section 4b, a pump 23 is placed under the floor grate 22 to collect static water 14. The pump 13 transports static water 14 through the pipe 15 to the flow source 7, where the supercritical flow 8 is discharged again. The embodiment of the containerless slope shown in Figure 4 is advantageous in situations where it is not desirable or possible to have a deep pool or stream, for example for non-swimmers.

A unique feature of the Tankless Slope 1 is its ability to simulate a variety of wave shapes for a wide range of wave riders of varying skill levels. A beginner's wave is characterized by a lack of steepness. In general, an amateur prefers waves with a front face angle of 45° or less. Three different wave types are characterized by such an angle of inclination: (1) an unbroken but rideable wave surface; (2) a whitewater burn; and (3) a flowing wave with a smooth unbroken shoulder. By setting the angle of the riding surface 3 on the containerless slope 1 in a range from 7 to 45 degrees, where 20 degrees is preferred, an ideal simulation of a suitable wave surface angle for an amateur can be produced.

The previously described figures 2-4 show a containerless slope 1 which is intended for an amateur and which simulates a stationary unbroken but rideable wave surface. Maintenance of this "unbroken" flow profile requires that the kinetic energy of the supercritical flow 8 always exceeds its potential energy at the downstream ash edge 4.

Figure 5 shows a tankless slope 1 intended for an amateur with a flow profile that simulates a stationary whitewater burn. When the velocity (i.e., kinetic energy) of an upsloping supercritical bed flow 8 moving in direction 9 is less than the gravitational potential energy at the downstream ridge 4, the bed flow 8 will form a hydraulic jump 24 before reaching the downstream ridge 4. White water 25 will thereby rolling down and to the side as waste water 11 and an effect corresponding to a stationary whitewater burn will be created on the riding surface 3 of the containerless slope 1. Maintaining this hydraulic condition requires that the kinetic energy of the supercritical flow 8 is always less than the potential energy at the downstream edge 4. Since the tankless slope 1 is not enclosed or has other sideway restrictions, white water 25 can be easily drained off at the sides 6a and 6b, so that immersion of supercritical flow is avoided. The relative position of the hydraulic jump 24 is determined by the speed of the supercritical flow 8. The higher the speed, the higher the position of the hydraulic jump 24 on the riding surface 3. The rider 10 performs water sliding maneuvers on the supercritical flow 8 and the white water 25.

A simulated flowing wave with a smooth unbroken shoulder can be produced on a tankless slope 1 by two general methods: (1) a cross-flow velocity gradient, and (2) a cross-flow pressure gradient. Which of these methods is used depends on the purpose and limitations of the containerless slope structure and available flow characteristics. A cross-flow velocity gradient is the preferred method when the structure of the containerless slope 1 is limited to a symmetrical design. A cross-flow pressure gradient is the preferred method when the initial supercritical flow 8, moving up the tankless slope 1, has a constant velocity.

Figure 6 shows a simulated flowing wave with a smooth unbroken shoulder, produced by introducing a cross-flow velocity gradient, produced by two different supercritical water flows 8a and 8b which are moved in direction 9 up the containerless slope 1 with the ridge 4. The "playing, breaking wave" the effect is the result of the initial supercritical flows 8a and 8b coming from the flow source 7a and 7b at two specific velocities and giving two subsequent hydraulic states, i.e. a higher velocity supercritical flow 8a over the top of the ridge (associated with flow source 7a) and a nearby lower velocity supercritical flow 8b (associated with flow source 7b) which does not reach the ridge 4 due to insufficient kinetic energy. The supercritical flow 8b with lower energy will slow down to a critical state and form a hydraulic jump under the ridge 4 with an associated subcritical flow of turbulent white water 25. This flowing white water 25 will be drained off at the side 6 as waste water 11, so that supercritical flow immersion is avoided.

Cross-flow velocity gradients can be produced either by placing several flow sources with different kinetic energy next to each other and at the same time facing them upwards as shown in Figure 6 or by suitable design of a single source (for example a pump) using a specially designed nozzle or plenum. Figure 7 shows the nozzle 17 with an asymmetric opening 26, consisting of a wide asymmetric opening side 16a and a narrow asymmetric opening side 26b which can produce flows with hydrostatic inclination. As shown in Figure 8, when the supercritical flow 8 first flows from the asymmetric opening 26 (shown by dashed line and arrows) it is thicker (eg deeper) on one side 8a than on the other side 8b, since the water surface either. If the supercritical flow 8 is moved over a fixed surface, such as the containerless slope 1, gravity will immediately try to equalize the thicker flow 8a, so that the flow equalizes itself. In this equalization process since a larger mass of water comes out of its asymmetric wide opening side 26a, this larger mass will increase its speed due to the fluid dynamic continuity law.

With a suitable angle and length of the tankless slope 1, two subsequent hydraulic conditions will occur, i.e. the supercritical flow 8a coming from the wide side 26a will clear the downstream ash edge 4 and maintain its supercritical character, while the flow 8b from the narrow side 26b will form a hydraulic jump and form white water 25 at the lower part of the surface to the containerless slope 1. Flowing white water 25 will be drained off along the side 26 as waste water 11, so that immersion of supercritical flow is avoided.

Cross-flow velocity gradients can also be produced as shown in Figure 9, if a single flow source 7 injects water into one side of a plenum 27 with an opening 31 facing the containerless slope 1. A core 28 of high velocity water emerges directly from the outlet of the supply pipe 29 and will hold together to a certain extent (as shown by dashed line 30) out of a part 31a to the opening 31 than from the part 31b to the opening 31. With a suitable angle and length of the containerless slope 1 will two subsequent hydraulic states occur, i.e. the supercritical flow 8a coming from the opening part 31a will clear the downstream ridge 4 and maintain its supercritical character, while the flow 8b from the opening part 31b will form a hydraulic jump and form white water 25 at the lower part of the tankless slope 1. The tankless the slope 1 drains off white water 25 along the side 6 as waste water 11, so that an immersion of supercritical flow is avoided.

The other general approach to simulating a flowing wave with a smooth unbroken shoulder is to generate a cross-stream pressure gradient. Such cross-flow pressure gradients can be formed, for example, by means of sleepers, submerged areas, injected water, a single side wall, etc. The preferred technique to avoid penetration or discontinuity on the riding surface 3 to the containerless slope 1 is by increased hydrostatic pressure. Figure 10 shows an asymmetrically extended containerless surface 1 (where the extension is shown with dashed lines) which forms a downstream ridge 4 of increasing height. With a suitable angle and length of the tankless slope 1, two subsequent hydraulic conditions will be formed, that is, the supercritical flow 8a flowing over the shortened side 4a to the downstream ridge 4 will clear and maintain its supercritical character, while the flow 8b has insufficient kinetic energy to clear the extended side 4b to the downstream ash edge 4 and will thereby form a hydraulic jump and white water 25 at the lower part of the riding surface 3 to the containerless slope 1. The same effect can be achieved and/ or reinforced by the extended side 4b having a greater angle of inclination than the riding surface 3. In this case, not only is the extended side 4b longer than the shorter side 4a, but it also has a greater height. The containerless slope 1 drains white water 25 along the side 6 as waste water 11, so that immersion of supercritical flow is avoided.

A natural consequence of a containerless surface asymmetry can on the one hand be used to solve the transient wave movement problems associated with starting the riding and on the other hand form an attraction that simulates a moving breaking wave corresponding to an ocean wave breaking parallel to the beach. In a start-up situation, due to the gradual build-up of water flow connected to the pump/motor or valve opening, there will be a supply of less volume, speed or pressure than what occurs later. Due to this upwelling, the water will be pushed by the stronger flow that emerges thereafter and such pushing will result in a build-up of water (i.e. a "moving" hydraulic jump or transient wave motion) at the leading edge of the flow. Increasing the upward slope of the side face will only serve to increase this problem, as an increasing volume of supercritical water transitions to subcritical and greater amounts of energy are required to continue pushing this wave motion upward.

If the initial kinetic energy of the inflowing water is not sufficient to push this subcritical build-up over the top of the slope, the transient wave motion may become so great that it will not be possible to push it over the edge, even when full flow is achieved . Asymmetry helps overcome the transient wave motions by lowering the necessary energy threshold for clearing and providing a "foothold" for the clearing process to begin.

Figures 11a, 11b and 11c show at three different times how the design of an asymmetrical containerless surface 1 solves the problem of pressure/flow delay during start-up. In Figure 1a, the supercritical flow 8 has started to flow in the direction 9 from the water source 7. A transient wave motion 32 is formed as the initially weak start-up flow hits the steeper area 3a of the riding surface 3. However, when the kinetic energy and volume of the supercritical flow 8 build up, it flows over the lower side 4b to the downstream ash comb 4 and onto the downward sloping transition surface 21. Figure 11b shows this initial procedure a few moments later when the water pressure/flow rate from the water source 7 has increased and the transient wave motion 32 has moved further up the containerless slope 1 and especially further up the steeper area 3a. Figure 1c shows the last step in the start-up where the transient wave movement 32 is pushed over the highest side 4a to the downstream ash comb 4 and the entire side surface is covered by supercritical flow 8.

If one reverses this process as shown in Figures 12a and 12a', 12b and 12b' and 12c and 12c' at different times, an effect occurs which simulates a breaking flowing wave at an angle to a beach. In Figures 12a (side view) and 12a' (top view) the supercritical flow 8 has reached a direction 9 from the reservoir 16. The high head of the reservoir 16 as indicated by the water level 18a results in a supercritical flow 8 with high kinetic energy out of the opening 31 in direction 9 which covers the riding surface 3 with a layer of water and which causes water runoff 11 over the entire downstream ash edge 4, which drain falls into the collection basin 34, as shown in figure 12a. Shortly after the rider 10 leaves a starting platform 33 to perform the water slide maneuver, the pump 13 stops and fills the reservoir 16. Seconds later figures 12b (side view) and 12b' (top view) illustrate the reduction in the water level 18b with a corresponding reduction in kinetic energy to the supercritical flow 8. A hydraulic jump with associated white water 25 is thereby formed at the highest end 4a to the downstream ridge 4 and then begins to move downwards towards the lower end 4b to the downstream ridge 4. At the same time, the rider 10a tries to stay upright in front of this wave which thereby simulates a flowing wave that breaks obliquely against a beach.

A few seconds later, Figure 12c (side view) and 12c'

(view from above) shows the water level 18c at the bottom of the reservoir 16. When the kinetic energy of the supercritical flow 8 equals the potential energy of the lower end 4b of the downstream ash edge 4, this movement will stop and the flow will take on the appearance of an ever-diminishing whitewater burn . The rider 10a stops the ride by going into the collection basin 34, whereby the pump 13 fills the reservoir 16 again so that the cycle can be repeated.

The proximity of the rider to the reservoir 16 and the opening 31, as shown in figure 12c, can cause a safety problem for the operator. These same problems which apply to all the previous figures can be easily solved by extending the riding surface 3 in a horizontal upstream direction. A horizontal expansion will provide a greater distance between the rider 10 and any upstream propulsion equipment and also remove the gravity induced force component which allows the rider to move in the upstream direction. In addition to improved safety, an appropriately dimensioned horizontal expansion of the riding surface 3 can result in significantly improved riding possibilities, i.e. the acceleration process.

With regard to this, figure 13a shows a generalized diagram for a horizontal expansion of the containerless slope 1. By adding this horizontal sub-region which is generally normal to the force of gravity and which is hereinafter described as a sub-equilibrium region 35, the extended riding surface 3 can be divided into three different areas, i.e. an over-equilibrium region 36 with transition (as shown by a dotted line 37) to an equilibrium zone 38 which in turn transitions to (presented by a dotted line 39) a sub-equilibrium region 35.

A supercritical water flow (not shown) moves in a direction 9 and forms a conformal flow over the sub-equilibrium region 35, the equilibrium zone 38 and the super-equilibrium region 36 and forms a sloping body of water on which a rider (not shown) can ride and perform surfing or water-gliding maneuvers which would not be possible without an appropriate combination of previously mentioned sub-areas.

The functional importance of these sub-areas is such that, with appropriate physical sizing, it becomes possible for the rider to increase speed and perform water-sliding maneuvers that would not be possible without this appropriate combination. In order to further explain how an appropriately sized riding surface can improve water maneuvers, a further discussion of how wave riding is performed is required. In modern surfing and gliding maneuvers, elements such as oscillation, speed and appropriate area ratio to the "wave" surface on which one is riding are of crucial importance. Each of these three elements will be discussed in more detail below.

1. Oscillation

The point of modern surfing is the ability for the rider to enjoy significant oscillations between supercritical and subcritical flow regions. As one gains greater expertise, the equilibrium region is used only as a transition region that one must necessarily pass through on the way to the super or subcritical regions. The oscillating movements also have the advantage that the rider has the opportunity to increase speed.

2. Speed

Speed is an important ingredient in performing modern surge manoeuvres. Without sufficient speed, one cannot "take off" in a maneuver. The method and means of increasing the speed of a suitably designed wave surface can be described as an analogy to increasing the speed of a swing as described in SCIENTIFIC AMERICAN, March 1989, pages 106-109. That is, in the same way as increasing the speed and the resulting height that can be achieved by "pumping" in a turn, the surfer can increase the speed and height of the wave by a corresponding pumping maneuver.

If in a turn you bend backwards at the highest point of the turn, your energy can be characterized as full potential energy. When you sink, this energy is gradually converted into kinetic energy and you increase your speed. When you reach the lowest point, the energy is completely kinetic energy and you move at top speed. When one begins to ascend the arch, the transformation is reversed: one slows down and then momentarily stops at the top of the arch. Whether you go higher (and faster) during a turn depends on what you have done during the turn. If you continue to curve, the upward movement is a mirror image of the downward movement and your center of mass ends up exactly as high as when you started the forward turn (minus friction). If you instead stand when you are at the lowest point (i.e. "pumping" the turn) you will turn higher and faster.

The significance of the subequilibrium region 25 in connection with the preceding discussion regarding swing dynamics is that the subequilibrium region 35 is the lowest point on the containerless slope 1 and on a wave. Standing or sliding down to this low point will result in a greater increase in speed than if you were standing at any other point on the riding surface. This increase in speed and total kinetic energy occurs due to two different mechanistic principles both of which can be used by a rider on the riding surface 3 or a wave.

By standing at the lowest point on the oscillating path, the rider's center of gravity will be raised and allow a greater vertical travel up the incline than the original descent. Crouching at the top of the track and alternating standing at the bottom provides an increase in vertical range and recovery of energy lost due to fluid friction.

The second mechanism that increases the kinetic energy occurs due to an increase in the angular rotation. When the rider in his path rotates around a point on the wave surface, continuing down or standing at the lowest point will increase his angular velocity in much the same way as an ice skater who, by pulling his arms in, increases the rotational speed due to conservation of momentum (i.e. increasing the moment of inertia). The increase in kinetic energy due to the work done in resisting the centrifugal force and because the kinetic energy is proportional to the square of the angular velocity, this increase in kinetic energy corresponds to an increase in velocity.

It should be noted that the analogy to swing dynamics is given only as one in 1lunstration. The oscillatory maneuvers of a surfer represent more complex mechanical and kinetic movements. However, it is believed that this analogy is applicable to illustrate the advantages of the present invention as discussed below.

The containerless slope as shown in figure 13a combines the under-equilibrium area 35, the under-equilibrium area 38 and the over-equilibrium area 36, so that the rider can oscillate, achieve the desired speed and have a suitable transition area available to perform modern surfing and sliding manoeuvres.

Figure 13b shows a cross-section of 13a, with the under-equilibrium area 35, the equilibrium zone 38 and the over-equilibrium area 36. The physical dimensions and the relationship between the different areas are described below.

The preferred size of the length of the underequilibrium area 35, measured in the direction of the flow 9, is, as a minimum, 1.5 to 4 times the vertical rise (measured from the lowest point of the underequilibrium area 35 to the uppermost point of the overequilibrium area 36) of the tankless slope 1 The length ratio is greater for containerless slopes 1 with a low height (e.g. 1 meter) and the length ratio is small for containerless slopes 1 with a high height (e.g. 6 meters).

A preferred shape of the equilibrium zone 38 can be defined in cross-section (taken in the flow direction) by part of a changing curve, for example an ellipse, parabola, hyperbola or spiral. If it is a changing curve, the shape of the equilibrium zone 38 is essentially arcuate (i.e., the rising water hits a decreasing radius or "closing" curve as it rises along the slab to the tankless slope 1.). The radius of the closing curve is at its smallest approximately equal to the radius of the leading edge of the overequilibrium area 36 and at its longest tangential to the horizontal plane. For the sake of simplification (but not as a limitation), the length of the upward equilibrium zone 38 can generally be defined as a distance approximately equal to the length of the rider's vehicle, i.e. about. 1-3 meters.

A preferred shape of the overequilibrium region 36 can be defined in cross-section (taken in the direction of flow) as part of a changing curve, for example an ellipse, parabola, hyperbola or spiral. If it is a changing curve, the design of the overequilibrium region 36 is initially arcuate (i.e. the rising water hits a decreasing radius as it rises along the face of the flow-forming device). The radius of this closed curve, at its largest, is always less than the radius of the longest arc of the equilibrium zone 38 and is at its smallest of a sufficient size, so that the rider still fits inside a resulting "tunnel wave" (discussed later). At a minimum, the length of the overequilibrium area 36 in the direction of flow 9 must be sufficient for the rider to accelerate in the opposite direction. At a maximum, the length of the overequilibrium region 36 in the direction of flow 9 is limited by the available head of an upwardly facing laminar flow.

In Figure 14, a rider 10 is shown in various stages of a surfing motion on a containerless slope 1 which is enhanced with an appropriately proportioned underequilibrium area 35, underequilibrium area 38 and overequilibrium area 36. The rider 10 is in a crouched position in the overequilibrium area 36 and increases speed as he moves downward over an adapted layer of supercritical water flow 8 originating from the water source 7 and moving in direction 9. When he reaches the lowest point of the under-equilibrium region 35, the rider 10 extends his body and at the same time pivots to return to the over-equilibrium region 36. The consequence of such maneuvering is that the rider 10 will increase speed in order to be able to perform further surfing movements. The process by which a rider can actively increase their speed is referred to as the acceleration process.

A practical modification of the sub-equilibrium area 35 and the equilibrium zone 38 on the riding surface 3 is the lateral (i.e. side to side) inclination of these areas in a direction perpendicular to the direction of flow 9. Such an inclination of the container-less slope 1 increases the throughput capacity as a result of the rider's movement in the direction of the slope due to the additional gravitational force component, caused by the mass of the rider in this direction. as a minimum, such a slope should be sufficient to be able to move the rider in the slope rent. As a maximum, this direction of inclination must still be able to allow water-sliding manoeuvres.

The rider capacity is a function of the number of riders who can use the containerless slope 1 over a given period of time. Since the size of the containerless slope 1 in practical application will be limited, the capacity is improved by limiting the time for a given rider. By tilting the riding surface 3, gravity will help move a rider from the starting point to the ending point. For general use, the preferred slope is 1 to 20.

Figure 15a shows a containerless slope 1 where the sub-equilibrium region 35 is sloped in a direction 41 which is at right angles to the flow direction 9. Figure 15b shows supercritical water 8 coming from a source 7 and moving in direction 9 over the sub-equilibrium region 35 (inclined), the equilibrium zone 38 and the overequilibrium area 36. As the rider 10a oscillates in a manner up and down on the containerless slope 1, he will simultaneously be moved from the starting platform 33 to an end pool 42 in a spiral path 43 as a result of the slope of the underequilibrium area 35. Immediately afterwards, the riders 10b can enter the containerless slope 1 and thereby show an improved rider capacity. In addition to an improved rider capacity, a slope of the underweight area 35 will assist in draining water from the containerless slope 1 upon shutdown.

The tankless slope 1 can also be used to simulate wave and swell shapes ideal for intermediate to advanced wave riders. A more advanced wave is characterized by its flat shape and steepness. In general, a powered wave rider will prefer waves with a front face angle greater than 45°. At such inclination angles, a steeper version of two previously discussed waveforms can be identified: (1) an unbroken but rideable wave face and (2) a flowing wave with a smooth unbroken shoulder. Importantly, under suitable conditions, a most widely considered third wave type can also be simulated, i.e. a current that progressively changes from horizontal to vertical and curls forward to form a tube or tunnel in which the wave rider can ride. Ideally, the tunnel opens to an unbroken wave shoulder with decreasing steepness. An experienced rider performs a maneuver from the tunnel to the shoulder and back again.

Figure 16a (topographical contour in feet) and Figure 16b (perspective) show a basic form of a tankless slope 1 which enables the formation of a supercritical separating flow forming a pipe or tunnel opening onto an unbroken shoulder. A unique feature of this basic form is its ability for this separating flow tunnel to form over a wide range of flow rates and thicknesses over a containerless slope that does not need to curve to the vertical plane. The basic shape shown in the perspective sketch 16b comprises the shoulder 44, an elbow 45, a chasm 46 and a tail 47 forming a tunnel wave as shown.

In the topographic contour shown in Figure 16a with flow direction 9, four distinct sub-regions of the riding surface 3 define the basic sloping shape: a shoulder 44 (the area to the left of the dashed vertical line), an elbow 45 (the area between the dashed vertical line and the vertical dotted line), an abyss 46 (the area between the vertical dotted line and the vertical dashed line) and a tail 47 (to the right of the vertical dashed line).

The shoulder 44 has a similar shape to the previously described riding surface shapes for unbroken but rideable wave surfaces (eg figures 2, 3 and 4). At the transition to the elbow 45, the riding surface 3 begins to bend in a smooth curved manner in the downstream direction. At the same time as it moves downstream, the riding surface 3 will get an increased steepness at the same time as the height of the downstream ash edge 4 simultaneously increases. At its maximum angle, the elbow 36 will transition to the abyss 37, whereby the riding surface 3 continues to increase to its maximum steepness and concavity and the ridge 4 reaches its maximum height. The topographical contour map shown in Figure 16a describes the preferred relationship to the shoulder 35, to the elbow 36, to the chasm 37. The recess 49 will act to vent subcritical flowing white water during start-up and also white water that occurs when the tunnel lip rejoins. The recess 49 is formed by a recess in the sub-equilibrium area 35.

The flow line characteristics as shown in Figure 16c require a suitable flow source 7 (eg pump, fast moving stream or pond/reservoir located at a certain height) which provides a supercritical bed flow of water 8 in the initial flow direction 9 (shown by arrow). The hydraulic properties of the flow and their synergistic interaction are best described with reference to each respective subarea.

In the shoulder region 44, since the only source of external pressure is gravity, a uniform slope of the surface will result in the flow 8 taking a substantially two-dimensional straight path up the riding surface 3 and over the downstream ash edge 4 as indicated by a flow line 48a. In the lower elbow area 45, a backward-facing movement will form a low-pressure area towards the side that is moved back. When the flow 8 gains greater height on the elbow 45, to avoid increased hydrostatic pressure, the flow 8 will begin to turn towards the area of lower pressure as indicated by flow line 48b. Now the flow 8 is no longer two-dimensional, it becomes three-dimensional because of this cross-flow pressure gradient.

The path of flow 8 as shown by flow line 48b has a parabolic slope. If it is hypothetically extended (shown as a continuous dashed curve), the last half of this parabola is directed downwards and angled away from the riding surface 3.

In the abyssal area 46, the recess 49 in the under-equilibrium area 35, together with an increasing steepness of the riding surface 3, will result in a parabolic path which is moved up straighter and closer, as shown by flow line 48c. As a consequence of this and as a result of distinctly inclined parabolic trajectories, the streamlines 48b and 48c will converge. As a result of the torque exchange at the convergence, both flows will change direction away from the riding surface 3. This leads to flow separation resulting in the desired stationary tunnel opening to the unbroken shoulder, upon which a rider 10 performs a waterslide maneuver. When the supercritical flow 8 separates from the riding surface 3, its new direction, as indicated by flow lines 48b and 48c, is across the original direction of flow 9. When the flow line again hits flow 9, white water 25 occurs and a drain 51 which is carried by the tail area 47.

A prerequisite for the formation of a flow tunnel is that the supercritical flow 8 must at least have sufficient speed to clear the downstream ash edge 4 at the shoulder area 44. Increases in the speed of the supercritical flow 8 will result in an increase in the tunnel diameter, i.e. an increase of the apparent wave size. When increases in the flow rate are not the limiting factor, the maximum tunnel diameter is primarily determined by the degree of inclination of the overequilibrium region of the abyss 46. If the inclination is approximately vertical, a maximum size can be achieved when the supercritical flow 8 at convergence no longer separates, i.e. it becomes an adapted flow. If the slope of the riding surface 3 exceeds the vertical plane and bends back on itself as shown in figure 17, an adapted flow can still result in a tunnel formation. The embodiment shown in Figure 17 preferably allows flow tunnel formation in situations where the velocity head of the supercritical flow 8 is significantly higher than the highest vertical point on the downstream ash edge 4 .

Within a certain range, modifications to the orientation of the elbow 45, the chasm 46 and the tail 47 are permitted to accommodate placement constraints and achieve certain flow tunnel effects. This is particularly important when it is necessary to use the drain 41 for other purposes, for example for a meandering river course as previously described. Changes in the orientation of the respective subregions (i.e., shoulder 44, elbow 45, chasm 46, and tail 47) within a given region can result in an increase or decrease in the convergence of streamlines 48b and 48c. Too little streamline convergence prevents separation and resulting tunneling. Excessive streamline convergence results in deceleration of the supercritical flow, formation of hydraulic jump and associated white water 25. However, there are cases where it may be desirable to produce such effects. The practical consequence of a supercritical separation enhanced by local hydraulic jumps is that different types of "wave-like" shapes can be produced, for example different combinations of flowing tunnel currents. Visually these currents appear distinct and from a rider's point of view they can ride differently using different manoeuvres. For example, a "snowball" effect in a flow tunnel induced by hydraulic jump formation in the tail 47 which forms a snowball of white water in the abyss 46, still surrounded by a tunnel wave, can be used to produce a further push by the rider, for example bodysurfer, in direction of the "shoulder". The orientation as shown in Figures 6a and 6c tends towards the area of maximum streamline convergence. The orientation as shown in figure 16d tends towards the area of minimum allowed streamline convergence.

In addition, different waveforms can be obtained by changing other parameters such as dimensions, orientation and arrangement of the shoulder 44, the elbow 45, the abyss 46 and the tail 47. The purpose of physical rearrangement of the shoulder 44, the elbow 45, the abyss 46 and the tail 47 is to change the direction of the flow 9. Here the same minimum/maximum angle ratios apply. Similarly, a reorientation of the retrograde current can form a left or mirror image of the previously shown right-refracting current.

Figures 18a, 18b, 18c, 18d, 18e and 18f show a unique feature of the containerless slope as shown in Figure 16, i.e. its unique flow shaping ability. That is, the waveform can allow (by means of a progressive increase of the speed of the water flow) the transformation of supercritical water flow 8 originating from a water source (not shown) in the direction 9 into a stationary white water wave along the entire shaping device (as shown in Figure 18a) to a stationary flowing wave with a broken shoulder (as shown in Figure 18b) to a stationary flow tunnel with an unbroken shoulder (as shown in Figure 18c). This progressive wave simulating forming method can be referred to as "flow transformation process".

As shown in Figures 18d, 18e and 18f, this flow transformation process enables the rider 10a or 10b to experience (or an operator can progressively produce) a variety of simulated wave types, such as whitewater burn, unbroken, flowing or tunnel on a single advantageously designed containerless slope 1 and all within a relatively short period of time. For example, the water flow can be pulsed or sequenced rhythmically to produce the various waveforms shown in Figures 18d to 18f thereby simulating the variable waves found on a beach. Changes in water flow rate can be achieved by any known combination of adjustable orifice reservoirs or by direct pump volume and speed control using variable speed motors, electrically adjustable speed drive systems or gear/clutch mechanisms.

Another way of increasing the capacity of the tankless slope 1 is shown in figures 19a, a9b and 19c at different times by means of a movable opening 52 which produces a movable water swath 53. The movable water swath 53 has a lateral component or movement direction (as shown by arrow 54) in addition to the previously described direction of flow 9. The lateral component of movement 54 preferably moves at a speed of 1 to 5 meters/second. As shown in Figure 19a, the rider enters the moving water slide 53 from the starting platform 33 and tries to adjust his speed with the lateral movement component 54, while at the same time performing a water slide maneuver. A few seconds later, the rider 10, as shown in figure 19b, has synchronized his lateral movement with the component of the lateral movement 54 of the moving water slice 53 and performs a turning maneuver according to the acceleration process. A few seconds later, in Figure 19c, the rider 10 has moved to the top of the movable water slice 53 and begins to move downward towards the termination pool 42. The movable opening 52 can act in the form of either a movable nozzle, movable grid, sequential opening of single openings or sequential opening of several openings (not shown). Other advantages of movable swath technology means that the flow along the edge that is not used by the rider is minimized and, in addition, you get the advantage of being able to move a rider from one point to another.

In connection with wave simulation, figure 19 shows an unbroken but rideable wave surface that is preferred by beginners. All of the other simulated wave types (e.g., a whitewater surf, a flowing wave with a smooth unbroken shoulder, or a flow tunnel with a smooth unbroken shoulder) are easily achieved by modifying the surface slope of the tankless slope 1 and/or the direction and velocity of the water- the current as mentioned earlier. In this regard, Figure 20 shows riders 10a, 10b and 10c simultaneously riding the movable water troughs 53a, 53b and 53c, respectively, all of which have a lateral movement component 54 originating from the movable opening 52. Progressive changes of the water velocity and the shape of the riding surface in accordance with the previously discussed principles, allows rider 10a to perform water slide maneuvers on an unbroken shoulder, rider 10b on a flowing wave with an unbroken shoulder and 10c on a flow tunnel with an unbroken shoulder. It should be noted that the moving swath technology allows the simulated waveform to transport energy from point a to point b and allow a phase change of the wave and change from point a to point b. There is no longer a stationary pattern, but rather, an intermediate momentum transport that occurs in the same direction as the opening movement.

The riding surface movement can also result in a torque transport and a non-stationary flow pattern. Figure 21 shows a tankless slope 1 with a suitable flow source 7 providing a supercritical bed flow of water in the initial flow direction 9 (shown by arrow) and over a flexible riding surface 3 which sequentially undulates in a pristaltic manner by means of a motion generating device 56, arranged below the surface. The motion generating device 56 causes the flexible riding surface 3 to rise or fall by sequentially inflating or deflating pneumatic/hydraulic bladders resulting in a motion component 54 in multiple directions as shown by the arrows 54. The rider 10 performs water-sliding maneuvers on the upward sloping bed flow that is formed of the undulating riding surface. Other commonly available methods also include mechanically driven wedges or rollers.

Changes to the containerless surface will change the flow's pressure gradients and will thereby give changeable wave-like characteristics, for example undulating currents, waves, flow tunnels or also different types of tunnel effects. Sequential undulation or peristaltic movement of a flexible containerless surface will produce a new slope with varying flow characteristics. At a minimum, the range of motion of the movable containerless surface may include that necessary to modify and redirect only a portion of a given flow, for example, where the tail 47 and chasm 46, Figure 16d, are turned against the flow discharge 9 to form a hydraulic jump with associated undulating current. As a maximum, the entire slope can be moved parallel or across the flow direction. Such a device has the further advantage that a rider 10 can be moved to an end point which is different from the starting point, which leads to an increased rider capacity. Optionally, the movement-generating device 56 can also be locked in one position, so that it also works during use with stationary flow.

Until now, the flow on the containerless surface has again been described as either an inclined or horizontal flow. When the source of such a flow is from a pump or a dam/reservoir with an associated opening, such as a nozzle, there is a high probability that oblique waves (i.e. non-coherent streamlines) will form at an angle to the flow from boundary layer disturbances associated with the opening's surroundings. Slant waves will not only interfere with the rider's execution of the water slide maneuver, but they can also grow and cause the entire stream to drown.

A solution to the formation of oblique waves is shown in figure 22, where an angled extension of the tankless slope 1 forms a ramp 55, onto which the opening 31 supplies a supercritical flow 8. This extension from an upstream edge 60 to the sub-equilibrium region 35 forms a ramp 55 with sufficient slope to prevent the formation of oblique waves (i.e. oblique waves are carried downstream). As a minimum, the vertical component for the ramp is 55 approx. 0.5 meters with a preferred angle of inclination of 20 to 40°. The ramp transitions smoothly into the sub-equilibrium region 35. Unlike horizontal or inclined surfaces on the tankless slope 1, it is permissible for the ramp 55 to use side walls, since oblique waves do not have sufficient energy to propagate both upstream and upward. The advantage of having side walls when the flow is going down is that the integrity of the flow can be maintained while avoiding lateral spread which can distribute the momentum of the flow.

In addition to avoiding the problem of sloping waves as described above, a further extension in the upstream direction of the ramp 55 to the tankless slope 1 will enable the riders to perform surfing and water-sliding maneuvers in a format that has not been possible heretofore , apart from the analogy of participants in the separate and distinct sports of skateboarding and snowboarding, i.e. half-pipe riding. In common parlance, the name "half-pipe" has arisen because the riding surface essentially resembles half of a pipe where the opening of this half-pipe faces upwards.

In contrast to the concept of a fluid half-pipe, figure 23 shows a containerless slope 1 fully extended, so that the rider also maneuvers on the ramp 55. At full extension, a supply basin 57 will supply a water flow that transitions to a supercritical water flow 8, briefly time after it has flowed over the upstream edge 5 to the tankless slope 1, after which it flows down to the ramp 55 in direction 9 over a suitable under-equilibrium region 35, equilibrium zone 38, over-equilibrium region 36, up and over the downstream ridge 4 and into a suitable receiving basin 58. The rider 10a enters the flow 8 at an appropriate point, for example below the counterweight area 35, where as a result of his initial forward momentum, the large friction against his vehicle and the added friction of the rider's weight-induced trim adjustments of the vehicle, the rider will (now 10b) be carried upwards to the overequilibrium region 36 when the downstream ash edge 4. At this point, as a result of that grave itation force is greater than the frictional force of the craft and the rider's weight-induced trim adjustments to reduce friction, the rider (now 10c) will hydroplane through the equilibrium zone 38 above the underequilibrium region 35 and execute a turn on the ramp 55 to return to the overequilibrium region 36 and repeat the cycle.

An extension of the containerless slope 1 in the form of a fluid half-pipe will provide the participants with a suitable environment to perform known surfing and water-sliding manoeuvres. Due to the combination of current, flat and downstream, a unique environment is formed where new maneuvers can be performed that are not possible on existing wave surfaces.

It is preferred that the width (measured in the direction of the supercritical water flow 8) of the containerless slope 1, shaped like a fluid half-pipe, is constant over its entire length. However, variations of the width with resulting variations of the flow shape cross-section are possible. The limitations of minimum and maximum width are a function of one's ability to perform water sliding maneuvers. With insufficient width, a rider will be unable to cope with the transition from the overbalance area 36 to the ramp 55 or vice versa. If it is too wide, the rider will not be able to reach or utilize the ramp 55 and perform the fluid half-pipe water slide maneuver. The width is also functionally related to the vertical rise from the sub-equilibrium region 35 to the downstream ash edge 4. A preferred height-to-width ratio is 1-5, with an outer range of 1-2 as a minimum and 1-10 as a maximum.

A preferred embodiment of the length of the half-pipe shaped containerless slope 1 is that a minimum of the length is sufficiently wide to be able to perform water slide maneuvers on it and at a maximum, a function of wishes and/or budget.

A preferred cross-sectional shape of the sub-equilibrium area 35 and the sloping riding surface 3 has previously been shown in Figure 13b. However, precautions must be taken in the design of the over-equilibrium area 36 to ensure a suitable flow of water up and over the downstream ash edge 4. Too great a steepness or height in relation to the operating dynamics of the supercritical flow 8, can result in an unfortunate or inappropriately positioned undulation or flow tunnel formation and a large build-up of turbulent white water in the sub-equilibrium region 35 which can culminate in the complete destruction of the supercritical flow 8. However, since advanced riders in order to maximize speed and perform certain maneuvers prefer a smooth supercritical region 36 that is close to or exceeds the vertical plane. It is therefore preferred that flowing or tunnel wave formation (if any) is limited to nearby areas and that the middle downstream half of the containerless slope 1 has a cross-section essentially as shown in Figure 13b and that the upper outer half has a cross-section essentially as a mirror image of Figure 13b, except when modified as outlined above.

Figure 24a shows in profile a standard design for a half-pipe shaped tankless slope 1. In this standard design, the cross-sectional height taken longitudinally in the flow direction remains constant over the length of the half-pipe. Figure 24b shows an asymmetric design, where the downstream edge 4 and the upstream edge 5 remain at constant heights and the width between respective edges 4 and 5 remains constant. However, the distance between respective edges 4 and 5 and the sub-equilibrium region 35 continues to increase at a constant rate of fall. The purpose of this particular asymmetric design is to increase the capacity of this half-pipe shape as a result of rider movement in the fall direction due to the additional vector component of the gravitational force, caused by the rider's mass in the fall direction.

In general, the height of the upstream edge 5 will exceed its streamline position on the downstream ash edge 4. This difference in height will ensure that the supercritical flow 8 will have sufficient dynamics to overcome all internal and external friction that it encounters on its way down, over, up and over the containerless slope 1. The preferred ratio by which the height of the upstream edge 5 exceeds the downstream ash edge 4 is 2 to 1, with an outer range from a minimum of 10 to 9, to a maximum of 10 to 1. It is also preferred that the respective upstream edge 5 and the downstream ash edge 4 remains at a constant height along the length of the half-pipe. Elevation variations are possible, however source basin 57 water dynamics, receiving basin 58 water dynamics and maintenance of flow line dynamics must be taken into account.

Variations in the longitudinal and transverse movement of the body of water as it flows on the half-pipe can result in improved rider capacity. Figure 25 shows a half-pipe shaped container slope 1 with a two-part basin 59. The supercritical water flow 8a is arranged on one half of the containerless slope 1. The source basin 57 supplying supercritical flows 8a is limited by the basin 59a to only one half of the tankless slope 1. Riders 10a, 10b, 10c and 10e enter the flow at any suitable point, for example the sub-equilibrium area 35 and perform water sliding maneuvers thereon. After a certain period of time, for example several minutes, a basin 59b is arranged to block the supercritical flow 8a, whereby the water stops flowing and the riders 10a, 10b, 10c and 10d can easily exit. At the same time or immediately after the blockage at the pool 59a, the pool 59a is opened and the supercritical flow 8b continues. Riders 10e, 10f and 10g enter the stream and continue to perform water slide maneuvers during the available time, re-establishing pool 59a and repeating the cycle. Modifications may also be made to the general half-pipe tankless slope 1 according to the principles discussed above, such as moving swathes or pressurized streams exiting the ramp 55 and all of these modifications are considered to be included in the previous description of the tankless slope 1.

Additional features of the tankless slope 1 include: (1) an inlet slide system; (2) a supply rope system; (3) moored vessels; (4) fence divisions and (5) connected synergistic attractors.

The supply system of the tankless slope 1 is the key to get the maximum capacity. So far, the only discussed supply system for the tankless slope 1 has been the platform 33 as shown in figures 12a, 15b and 19a. The starting platform 33 is located close to the containerless slope 1 at its platform floor level with approximately the same height as part of the slope of the riding surface 3. An alternative method of supply to the containerless slope 1 is shown in Figure 26. Skids 61a, 61b and 61e are located at the under-equilibrium area 35, the equilibrium zone 35 and the over-equilibrium area 38 of the containerless slope 1. The rider 10 slides down the slide 61 and hits the supercritical water jet 8, whereby the rider 10 performs a water slide maneuver. In order to minimize disturbances to the flow 8, it is preferred that as little water 62 as possible is supplied in the slide 61 in order to reduce the friction. As an alternative, drainage grates 63 can be arranged which remove excess water 62 from the slide. The slide 61 can be located anywhere along the edge 6 or along the ridge 4, but the preferred location is shown in figure 26. In order to make it as comfortable as possible for the rider 10 when transitioning from the slide 61 to the containerless slope 1, it is preferred that the height and the last part of the slide 61 enable the rider 10 to enter on top of the supercritical flow 8 and relatively parallel to the plane of flow. The slide 61 may be made of fiberglass, concrete, concrete covered foam, reinforced fabric, metal, or any other smooth and structurally stable surface suitable for this application. The slide 61 may be designed to handle multiple riders.

Another type of supply system for the containerless slope 1 is by means of ropes. Figure 27 shows the containerless slope 1 with supercritical water flow 8 in the form of a stationary tunnel wave with an unbroken shoulder. Controllable drive ropes 26 are moved in direction 56 and pull the rope 66 which is attached to the vehicle 67, in which riders 10a, 10b, 10c and 10d are placed. When entering the supercritical flow, the riders 10 are able to exercise some control of their position during the execution of the water slide maneuvers. Controllable drive ropes 64 are moved at a preferred speed of 0.5 to 2 meters/second. Over a certain period of time, as indicated by the positions 68a, 68b, 68c, 68d and 68e, the rope 66, the vehicle 67 and the riders 10a, 10b, 10c and 10d are pulled from the start area 69 to the exit area 70. It is preferred that the controllable rope operation 64 allows movements in and out to position the rider 10 and the vehicle 67 as best as possible on the waveform, for example in the tube. When the rider 10 and the craft 67 are roped into the supercritical flow 8, the rope 66 can possibly be released and the rider 10 will be able to perform unlimited water sliding manoeuvres.

Another mooring system is shown in Figure 28, where the craft 67 is attached by means of a mooring 71 to a pin 72 attached to the riding surface 3 of the containerless slope 1. When there is no water flow, the participants can stroll over the dry riding surface 3 and place themselves in the respective vessels. When the supercritical flow 8 is started, as shown in figure 28, the rider can perform water sliding maneuvers for a certain period of time, after which the flow 8 decreases, the rider 10 dismounts and the cycle is repeated.

A fence 73 as shown in Figure 29 is used on the tankless slope 1 to limit the access of the rider 10 to a certain area, while at the same time allowing either supercritical flow 8, white water 25 or waste water 11 to pass underneath. The fence 73 is not a restriction for the water, it only limits the rider's 10 movement possibilities on the supercritical flow 8. The fence 73 preferably consists of a parallel handle or a series of handles. If there is more than one handle, there must be sufficient distance between them to prevent the rider's hand or foot from getting stuck. The fence 73 may be made of padded rope, metal, wood, fiberglass, or any other non-abrasive padded material. It is preferred that the fence is cantilevered over the water flow, but it is also possible with fence posts with minimal friction. The fence 73 can also be used to divide the device into a certain number of lanes on the riding surface 3, so that the riders do not come into contact with each other.

The tankless slope 1 can also be combined with other synergistic attractions or structures to utilize the kinetic energy of motion of the water supplied to or coming out of the tankless slope 1. In connection with combinations on the upstream side, figure 30 shows a tankless slope 1, located at the outlet 74 to a basin 75. Such combinations provide a supply basin 57 with minimal operating costs for the tankless slope 1, while providing an energy dissipating/downstream erosion system for the dam operator. Erosion control is achieved by the containerless slope 1 dissipating the kinetic energy of the drain 47 before it hits another less erosion-resistant course further downstream.

Combining the outlet 74 from the tankless slope 1 to other half-pipe shapes in series will also make it possible to utilize the remaining kinetic energy of the supercritical flow 8 or the wastewater 11 coming out of the tankless slope 1 to supply water to subsequent containerless slopes as shown in Figure 31. Figure 32 shows the outlet 74 from the containerless slope 1, connected to a white water river course 76.

It should also be noted that in connection with the invention described above, corresponding flow characteristics can be achieved for aesthetic reasons, for example a fountain or other water sculptures. As an example, the shapes shown and described in connection with figures 16a to 16d, figure 17 and figures 18a, 18b and 18c can be used to produce attractive water fountains. As discussed above, these shapes and flow parameters can be varied to achieve different waves or other shapes when the flow is separated. In addition, an attractive variable fountain can be produced with random variation of the flow parameters against a waveform or shape as shown in Figures 12, 12b and 12c and Figure 21. This feature increases the interest produced by a non-static fountain.

In particular, a fountain made in accordance with the principles of the present invention can use the containerless slope described particularly in connection with Figures 1 to 12. Furthermore, the downward facing ramp 55 (Figure 22) and the half-pipe designs (Figure 23) can also be used to to generate unique water fountain forms. Likewise, the movable slat design as indicated in Figures 18 and 19 may provide a suitable structure for similar water fountain shapes.

As the person skilled in the art will know, certain modifications and changes can be made without deviating from the scope of protection of the present invention. For example, the specified proportions do not have to be geometrically precise, approximations are sufficient. The same applies to limitations of angles, radii and ratios. The temperature and density of the water will be slightly different, although the temperature ranges that are comfortable for surfers/riders are relatively limited.

The terms and expressions that have been used in the preceding description are used as descriptive terms and not limitations and by using such expressions, it is not intended to exclude corresponding features that are shown and described or parts thereof. The scope of protection of the invention is only defined and limited to the content of the subsequent claims.

Claims (13)

1. Water riding device where water flows on a generally sloping surface which forms a riding surface (3), and where a water stream (8) is directed up onto the sloping riding surface (3), the water stream (8) essentially adapting to the sloping riding surface ( 3), characterized in that the riding surface (3) is containerless and without barrier or enclosure so that it cannot be filled or flooded with water, and so that boundary layer-induced subcritical flow and associated flow disturbance along the perimeter or edge (4,5,6) of the riding surface (3) is eliminated, as the surface (3) is designed without lateral water restrictions or walls. 2. Device as stated in claim 1, characterized in that overflowing white water rolls downwards and to the side as waste water so that supercritical flow immersion is avoided. 3. Device as stated in claim 1, characterized in that it further comprises a collecting basin (12) which contains water at a level that is equal to or lower than the lowest part of the riding surface (3), so that water (8) on the riding surface (3) can be flooded (11) into the collecting basin (12) and thereby supercritical flow immersion is avoided. 4. Device according to claim 1, characterized in that the riding surface (3) comprises a shaped surface which has a mainly horizontal part (50), and a downstream arranged sloping part which abuts the horizontal part (50). 5 . Device according to claim 1, characterized in that the inclined riding surface has a lower inclined part (35), a middle mainly horizontal part (38) and an upper inclined part (36), the current being introduced on the lower part (35 ), and then flows on the middle part (38), and then on the upper part (36). 6. Device according to claim 5, characterized in that it further comprises a nozzle (17) for driving a stream of water towards the shaped surface, where the stream of water is driven towards the horizontal part (50) and flows up the inclined part, and is then emptied by the sloping part and/or eddies back on the water flow. 7. Device according to claim 1, characterized in that it comprises devices (13,16,17,31) to vary the quantity, speed and/or pressure of water flow, but thereby to create the desired water flow effects on the riding surface. 8. Device according to claim 1, characterized in that the water stream comprises at least two separate and independent streams (8a, 8b) which are sprayed upwards on the riding surface, which streams can have different amounts, speed and/or pressure, so that a desired water flow effect on the riding surface. 9. Device according to claim 1, characterized in that it comprises one or more lateral transition surfaces (34) adjacent to the riding surface to accommodate a water rider (10) that has come outside the riding surface itself. 10. Device according to claim 9, characterized in that at least one of the side transition sheets (34) inclines downwards. 11. Device according to claim 10, characterized in that at least one of the side transition rafts (34) comprises a sump. 12. Device according to claim 1, characterized in that it comprises a wave-forming structure (36) on the riding surface, the wave-forming structure having a mainly concave curvature so that water flowing on the wave-forming structure also swirls back on the flow so that an overflow wave is formed on this. 13. Device according to claim 12, characterized in that the wave-forming structure (38,36) has both a horizontal and a vertical curvature.