FIELD OF INVENTION The present invention relates to a wave generating apparatus. In particular, the invention relates to a wave generating apparatus that includes at least one submerged lateral surface that mimics a shore gradient in use.

BACKGROUND ART

Generation of surface waves by movement of a submerged body through the water or hull across the water surface is known. For example, bow waves are generated as the bow of a ship or boat moves through a body of water. As bow waves spread out, they define the outer limits of a ship's wake.

With increasing popularity of surfing and crowding of popular surf locations in many countries, wave generating machines have been devised. The machines and systems devised have included, for example, circular wave pools where wave are generated by a hull or other wave generating body moving through the water, generally in combination with directional water flow in the pool. In such cases, the physical characteristics of the pool, such as pool floor depth and shape, side wall configuration and so on, may also impact on wave generation and are important aspects of any design. Many of these types of pool are relatively energy intensive in their operation. Also, they are generally not applicable to existing bodies of water. That is, they are a pool and the mechanisms used are not appropriate for application in naturally existing bodies of water. The subject matter claimed herein is not limited to embodiments that solve any disadvantages or that operate only in environments such as those described above. Rather, this background is only provided to illustrate one exemplary technology area where some embodiments described herein may be practice. SUMMARY OF INVENTION

The present invention relates to a wave generating apparatus. In particular, the invention relates to a wave generating apparatus that includes at least one submerged lateral surface that mimics a shore gradient in use.

According to one aspect of the invention there is provided a wave generating apparatus comprising:

a forwardly disposed water displacement body adapted to generate a wake as the wave generating apparatus moves through a body of water;

a longitudinal wall associated with the water displacement body and extending longitudinally from the water displacement body; and

at least one lateral wing extending outwardly from a lower portion of the wall, wherein an upper surface of the lateral wing defines a wave generating surface having a positive gradient extending outwardly from the wall which, in use, acts as an artificial shore line whereby waves are generated from the wake generated by the water displacement body.

The above components of the wave generating apparatus may or may not be physically connected. For example, the water displacement body and the wall may be physically connected to one another, or the wall and the at least one lateral wing may be physically connected to one another, or both.

In one embodiment, the at least one lateral wing is independent of the water displacement body and is not directly or indirectly connected thereto, and wherein the at least one lateral wing, in use, is adapted to travel through the body of water at the same speed as the water displacement body and at a fixed position relative to the water displacement body. In a preferred embodiment, as will be discussed in some detail below, the at least one lateral wing comprises a pair of opposed lateral wings, one extending from each side of the lower portion of the wall. Preferably, the opposed lateral wings extend outwardly and rearwardly from the lower portion of the wall. For example, the opposed lateral wings may define substantially parallelogram wave generating surfaces.

While the positive gradient defined by the wave generating surfaces may be linear, that is the wave generating surfaces may be planar, it is envisaged that in a preferred embodiment the positive gradient is substantially sinusoidal. That is, the wave generating surfaces are preferably curved, partly in one direction and then in the other direction with a relatively small amplitude and relatively large wavelength. The opposed lateral wings extend from a lower portion of the longitudinal wall. Preferably, the opposed lateral wings extend from a lower edge of the longitudinal wall.

The form of the water displacement body is not particularly limited. For example, this may be of a hull-like form, a block or other suitable form. In one embodiment, the water displacement body is in the form of a wedge including a substantially planar upper surface, a declined planar lower surface that forms a forward edge with the planar upper surface, two opposing sides extending between the planar upper surface and declined planar low surface, and a rear wall. It may be desirable to reduce the potential for drag through the body of water. As such, in a preferred embodiment an upper surface of the longitudinal wall, extending from the water displacement body, is contiguous with the planar upper surface of the water displacement body. Also, the longitudinal wall preferably comprises a neck portion that extends from the rear wall of the water displacement body, and wherein a lower surface of the neck portion declines to a position where the at least one wing extends from the longitudinal wall. It may also be preferred that the thickness of the at least one wing be minimised so as to minimise drag of the at least one wing through the body of water.

The draft of the water displacement body in the water is roughly half the wave height of waves generated by the wave generating apparatus. That is, a trough is created by the water displacement body and a corresponding crest is formed as a result.

The dimensions of the wave generating apparatus will be dependent on the desired waves to be generated. Generally, although not wishing to limit the invention in any way, for a wave height x to be generated, the at least one wing is orientated such that the wave will break at approximately a mid-point along the at least one wing and at a point approximately 5 times x from a nearest edge of the water displacement body. According to another aspect of the invention there is provided a method for generating a wave comprising:

moving a water displacement body through a body of water to generate a wake; and

moving a wave generating surface through the body of water beneath the wake generated by the water displacement body,

wherein the wave generating surface has a positive gradient extending outwardly from a line of movement of the water displacement body through the body of water and acts as an artificial shore line whereby waves are generated from the wake generated by the water displacement body.

In a preferred embodiment the water displacement body and the wave generating surface are moved through the body of water at the same speed and at a fixed position relative to one another. The velocity of movement of the wave generating apparatus through the water will be dependent on the waves desired to be generated and the related dimensions of the wave generating apparatus. Generally, the velocity of the waves created is approximately 5m/s for 1m waves. To increase wave height, the velocity has to increase by the square root of the multiplying factor. For example to increase the wave height by a factor of two, the speed has to increase by the square root of two, which is 1.414. The draft of the wave generating apparatus, however, has to be doubled, as does the distance from the water displacement body at which the wave(s) will break. As such, the physical parameters are increased in a linear fashion while the speed increases by the square root of the multiplying factor.

The present invention consists of features and a combination of parts hereinafter fully described and illustrated in the accompanying drawings, it being understood that various changes in the details may be made without departing from the scope of the invention or sacrificing any of the advantages of the present invention.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS

To further clarify various aspects of some embodiments of the present invention, a more particular description of the invention will be rendered by references to specific embodiments thereof, which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail through the accompanying drawings in which:

FIG. 1 illustrates a wave generating apparatus.

FIG. 2 illustrates another view of the wave generating apparatus of Figure 1.

FIG. 3 illustrates a plan view of a wave generating apparatus.

FIG. 4 illustrates a rear view of the wave generating apparatus of Figure 3. FIG. 5 illustrates a perspective side view of the wave generating apparatus of Figure 3.

FIG. 6 illustrates a forward perspective side view of the wave generating apparatus of Figure 3. FIG. 7 illustrates a forward underside view of the wave generating apparatus of Figure 3. FIG. 8 illustrates a further underside view of the wave generating apparatus of Figure 3. FIG.9 illustrates a further underside view of the wave generating apparatus of Figure 3.

FIG. 10 illustrates a rearward underside view of the wave generating apparatus of Figure 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides a wave generating apparatus. In particular, the invention relates to a wave generating apparatus that includes at least one submerged lateral surface that mimics a shore gradient in use.

Hereinafter, this specification will describe the present invention according to the preferred embodiments. It is to be understood that limiting the description to the preferred embodiments of the invention is merely to facilitate discussion of the present invention and it is envisioned without departing from the scope of the appended claims.

Referring to the Figures, a wave generating apparatus 10 is illustrated. The wave generating apparatus includes a water displacement body 11 , a longitudinal wall 12 extending from the water displacement body 11 and a pair of opposed wings 13. As illustrated, these components are connected to one another. However, as discussed above, this is not necessarily the case and each component may be independently mounted.

The water displacement body 11 is designed to cut through the water, generally at or just below the surface of the water. The water displacement body 1.1 is in the form of a wedge, including an upper planar surface 14 and a declined planar lower surface 15 that forms a forward edge 16 with said planar upper surface 14. Two opposing sides 17 extend between the planar upper surface 14 and the declined planar low surface 16, and a rear wall 18 completes the wedge.

The upper planar surface 14 of the water displacement body 11 is contiguous with an upper surface 19 of the longitudinal wall 12. The longitudinal wall 12 substantially extends along the length of the wave generating apparatus 10 and is centrally disposed relative to the water displacement body 11. As illustrated, the longitudinal wall comprises a neck portion 20 that extends from the rear wall 18 of the water displacement body 1 . A lower surface 21 of the neck portion declines to a position 22 where the pair of wings 13 extends from the longitudinal wall 12. Generally, the pair of wings 13 extend from a lower edge 23 of the longitudinal wall 12. As depicted, the pair of wings 13 extend outwardly and rearwardly from the longitudinal wall 12. In plan view, as best illustrated in Figure 3, the wings 13 take the form of a parallelogram extending in an opposing manner from each side of the longitudinal wall 12. As such, a wake emanating from the water displacement body 11 passes over an inner portion 24 of the wings 13, representing a portion of the wings that is relatively deep within the body of water, through to an outer portion 25 of the wings 13, representing a portion of the wings that is relatively shallow within the body of water. This advantageously results in wave generation in a similar way to that seen on a natural shore line with such contours.

The wings 13 illustrated are curved or substantially sinusoidal in. nature, although they could also be linear (i.e. planar). As such, depth of water at the inner portion 14 of the wings gradually decreases initially, ensuring that wakes generated by the water displacement body 1 1 do not encounter any drag until they have advanced clear of the water displacement body 11. As the depth of the water decreases, approaching the outer portion 25 of the wings 13, this forces the wakes to break thereby generating waves. It is envisaged that the wings 13 may also be angled in some instances to obtain suitable break characteristics of the waves.

Advantageously, the profile or thickness of the wings 13 is minimised, at least in the direction of movement of the wave generating apparatus 10 to avoid any negative impact associated with drag. That is the profile of the leading edge of the wings 13 is minimised to achieve minimal displacement of water on movement of the wings 13 through the body of water.

It is envisaged that the wave generating apparatus 10 may be moved through the body of water using, for example, a system including tracks or rails. Such a system may be driven by any means as would be readily appreciated by a person of skill in the art. For example, a cable may be employed to impart movement to the wave generating apparatus 10. In such a case, the wave generating apparatus 10 may be mounted on the cable, or other mechanism, by any suitable means. It may be that the wave generating apparatus can be towed by a powered vessel. All such embodiment are within the ambit of the present invention.

Unless the context requires otherwise or specifically stated to the contrary, integers, steps or elements of the invention recited herein as singular integers, steps or elements clearly encompass both singular and plural forms of the recited integers, steps or elements.

Throughout this specification, unless the context requires otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated step or element or integer or group of steps or elements or integers, but not the exclusion of any other step or element or integer or group of steps, elements or integers. Thus, in the context of this specification, the term "comprising" is used in an inclusive sense and thus should be understood as meaning "including principally, but not necessarily solely".

It will be appreciated that the foregoing description has been given by way of illustrative example of the invention and that all such modifications and variations thereto as would be apparent to persons of skill in the art are deemed to fall within the broad scope and ambit of the invention as herein set forth.