U.S. patent application number 11/044554 was filed with the patent office on 2005-09-22 for wave forming apparatus and method.
Invention is credited to McFarland, Bruce C..
Application Number | 20050207845 11/044554 |
Document ID | / |
Family ID | 28456595 |
Filed Date | 2005-09-22 |
United States Patent
Application |
20050207845 |
Kind Code |
A1 |
McFarland, Bruce C. |
September 22, 2005 |
Wave forming apparatus and method
Abstract
A wave forming apparatus has a channel for containing a flow of
water with an inlet end connected to a water supply, a base, and
spaced side walls, a weir in the base at the inlet end of the
channel, and at least one bed form in the channel downstream of the
weir. The bed form has an upwardly inclined upstream face extending
downstream of the leading end, an upper portion, and a downwardly
inclined downstream face extending from the upper portion to the
trailing end. A primary flow path for water extends over the weir
and bed form. A secondary flow passageway extends through the bed
form, with a first end adjacent the trailing end of the bed form,
and a second end in the bed form upstream of the first end.
Inventors: |
McFarland, Bruce C.; (Solana
Beach, CA) |
Correspondence
Address: |
GORDON & REES LLP
101 WEST BROADWAY
SUITE 1600
SAN DIEGO
CA
92101
US
|
Family ID: |
28456595 |
Appl. No.: |
11/044554 |
Filed: |
January 26, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11044554 |
Jan 26, 2005 |
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10372549 |
Feb 24, 2003 |
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10372549 |
Feb 24, 2003 |
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10103600 |
Mar 19, 2002 |
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6629803 |
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Current U.S.
Class: |
405/79 |
Current CPC
Class: |
E04H 4/0006 20130101;
A63G 3/02 20130101; E04B 9/06 20130101; A63B 69/0093 20130101 |
Class at
Publication: |
405/079 |
International
Class: |
E02B 003/00 |
Claims
I claim:
1. A wave forming apparatus, comprising: a channel for containing a
flow of water, the channel having an inlet end connected to a water
supply, a base, and spaced side walls, a weir in the base at the
inlet end of the channel, and at least one bed form in the channel
downstream of the weir; the bed form having a leading end and a
trailing end, an upwardly inclined upstream face extending
downstream of the leading end, an upper portion, and a downwardly
inclined downstream face extending from the upper portion to the
trailing end, the weir and bed form each extending outwardly to the
side walls to define a primary water flow path from the inlet over
the weir and bed form; and a secondary flow passageway provided in
the channel, the secondary flow passageway having a first end
communicating with the primary water flow at a location adjacent
the trailing end of the bed form, and a second end communicating
with the primary water flow at a location upstream of the first
end.
2. The apparatus as claimed in claim 1, wherein the upstream face
of the bed form is concave and the downstream face is concave.
3. The apparatus as claimed in claim 1, wherein the bed forms are
of solid construction and the secondary flow passageway extends
through each bed form.
4. The apparatus as claimed in claim 1, wherein the bed form
comprises an outer shell and a hollow interior, the outer shell
having openings for secondary flow and the secondary flow
passageway comprising the hollow interior of the bed form.
5. The apparatus as claimed in claim 1, comprising a flume having a
first end, a second end, and outer sides, the channel containing
the weir and bed forms extending along a central portion of the
flume from the first end to the second end, and the flume having
side portions on opposite sides of the channel extending from the
respective channel side wall out to the opposite sides of the
flume, the side portions of the flume being shallower than the
channel.
6. The apparatus as claimed in claim 5, wherein each side portion
is tapered upwardly from the channel side wall to the outer side of
the flume.
7. The apparatus as claimed in claim 1, wherein the bed form
comprises a hollow shell and at least one pedestal is provided
inside the shell extending between the base of the channel and the
upper portion of the bed form.
8. The apparatus as claimed in claim 7, wherein the bed form is
adjustably mounted and the pedestal is adjustable in height to vary
the bed form height.
9. The apparatus as claimed in claim 7, wherein the bed form is
formed of flexible material, the leading end of the bed form is
secured in the base of the channel, and the trailing end of the bed
form is free, and a second pedestal is provided adjacent the
trailing end for supporting the trailing end above the base, the
further pedestal being adjustable in height to vary the spacing of
the trailing end above the base defining a first vent opening at
the first end of the secondary flow passageway.
10. The apparatus as claimed in claim 9, wherein a series of second
pedestals are provided across the width of the trailing end of the
bed form, the second pedestals being independently adjusted whereby
the size of the vent opening may be varied across the width of the
bed form.
11. The apparatus as claimed in claim 1, wherein the trailing end
of the bed form is spaced above the base of the channel to provide
a vertical drop-off at the trailing end of the bed form, the
trailing end being at a predetermined first height above the base
of the channel.
12. The apparatus as claimed in claim 11, wherein there are at
least two spaced bed forms in the channel and the upper portion of
the second bed form is at a predetermined second height above the
base of the channel, and the trailing end and upper portion
together define a predetermined tail elevation factor (TEF)
comprising ratio of the first height to the second height.
13. The apparatus as claimed in claim 1, wherein a series of
identical bed forms are provided at spaced intervals along the
channel, whereby a series of standing waves are formed.
14. A wave forming apparatus, comprising: a channel for containing
a flow of water, the channel having an inlet end connected to a
water supply, a base, and spaced side walls, a weir in the base at
the inlet end of the channel, and at least one bed form in the
channel downstream of the weir; the bed form having a leading end
and a trailing end, an upwardly inclined upstream face extending
downstream of the leading end, an upper portion, and a downwardly
inclined downstream face extending from the upper portion to the
trailing end, the weir and bed form each extending outwardly to the
side walls to define a primary water flow path from the inlet over
the weir and bed form; and the trailing end of the bed form being
spaced above the base of the channel to define an abrupt vertical
drop-off of predetermined height.
15. The apparatus as claimed in claim 14, wherein a second bed form
is provided in the channel downstream of the first mentioned bed
form, the upper portion of the second bed form is at a
predetermined second height above the base of the channel, and the
ratio of the height of the tail end of the bed form to the second
height comprises a predetermined tail elevation factor.
16. The apparatus as claimed in claim 14, wherein the leading face
of the bed form is of generally concave shape, and the trailing
face has a first, convex portion extending from the upper portion,
and re-curves into a generally flat portion adjacent the tail end
of the bed form.
17. The apparatus as claimed in claim 1, including at least one
oblique bed form downstream of the first bed form in the water flow
direction extending at an oblique angle to the water flow
direction.
18. The apparatus as claimed in claim 1, including at least one
bend in the channel downstream of the bed forms.
19. The apparatus as claimed in claim 1, wherein the primary
channel has an inlet end and an outlet end, and including a
secondary channel containing a second flow of water and
intersecting the outlet end of the primary channel at an oblique
angle.
20. The apparatus as claimed in claim 1, wherein the primary
channel comprises a loop having opposite straight portions and
curved end portions, and bed forms are located in each straight
portion of the loop and at the junction between each straight
portion and the respective curved end portion in the water flow
direction.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of application Ser. No.
10/372,549 filed Feb. 24, 2003, which was a Continuation-In-Part of
application Ser. No. 10/103,600 filed Mar. 19, 2002, now U.S. Pat.
No. 6,629,803.
BACKGROUND OF THE INVENTION
[0002] The present invention relates generally to a wave forming
apparatus and is partially concerned with water rides of the type
provided in water-based amusement parks, particularly a wave
forming apparatus and method for forming surfable waves, or a water
toy.
[0003] Naturally occurring waves occur in the ocean and also in
rivers. These waves are of various types, such as moving waves
which may be of various shapes, including tubular and other
breaking waves. A relatively rare type of wave in nature is the
standing wave, which has a steep, unbroken and stable wave face.
This type of wave can have enough power and velocity to support
surfing on the wave face without causing the wave to decay rapidly.
This wave, if forced to decay, for example by overly obstructing
the flow, reforms naturally when the obstructions are removed.
Natural standing waves have been shown to occur where water flows
across natural river bed formations, known as anti-dunes. Upon flow
over anti-dunes, the water flow rises into a natural standing wave.
Natural standing waves occur in the Waimea Bay river mouth of the
Waimea River on the Hawaiian island of Oahu, on the Snake River in
Wyoming, and several other places.
[0004] Surfers are constantly searching for good surfing waves,
such as tubular breaking waves and standing waves. There are only a
few locations in the world where such waves are formed naturally on
a consistent basis. Thus, there have been many attempts in the past
to create artificial waves of various types for surfing in
controlled environments such as water parks. In some cases, a sheet
flow of water is directed over an inclined surface of the desired
wave shape. Therefore, rather than creating a stand-alone wave in
the water, the inclined surface defines the wave shape and the
rider surfs on a thin sheet of water flowing over the surface. This
type of apparatus is described, for example, in U.S. Pat. Nos.
5,564,859 and 6,132,317 of Lochtefeld. In some cases, the inclined
surface is shaped to cause a tubular form wave. Sheet flow wave
simulating devices have some disadvantages. For example, since
these systems create a fast moving, thin sheet of water, they
produce a different surfing experience to a real standing wave.
[0005] In other prior art wave forming devices, a wave is actually
simulated in the water itself, rather than being defined by a
surface over which a thin sheet of water flows. U.S. Pat. No.
6,019,547 of Hill describes a wave forming apparatus which attempts
to simulate natural antidune formations in order to create waves. A
water-shaping airfoil is disposed within a flume containing a flow
of water, and a wave-forming ramp is positioned downstream of the
airfoil structure. In other prior art arrangements, such as U.S.
Pat. No. 3,913,332 of Forsman, a wave generator is driven around a
circular body of water in order to create waves. This arrangement
is also complex and will produce traveling waves, not standing
waves.
SUMMARY OF THE INVENTION
[0006] It is an object of the present invention to provide a new
and improved wave forming apparatus and method.
[0007] According to one aspect of the present invention, a wave
forming apparatus is provided, which comprises a channel for
containing a flow of water, the channel having an inlet end
connected to a water supply, a base, and spaced side walls, a weir
in the base at the inlet end of the channel, and at least one bed
form in the channel downstream of the weir, the bed form having a
leading end and a trailing end, an upwardly inclined upstream face
extending downstream of the leading end, an upper portion, and a
downwardly inclined downstream face extending from the upper
portion to the trailing end, the weir and bed form each extending
outwardly to the side walls to define a primary water flow path
from the inlet over the weir and bed form, and a secondary flow
passageway provided in the channel, the secondary flow passageway
having a first end communicating with the primary water flow at a
location adjacent the trailing end of the bed form, and a second
end communicating with the primary water flow at a location
upstream of the first end.
[0008] In an exemplary embodiment of the invention, the first end
of the secondary flow passageway comprises a first vent extending
across the full width of the bed form. The second end may comprise
a second vent extending across the full width of the bed form, or
may comprise spaced second vents adjacent opposite sides of the bed
form, each vent extending across the upper portion of the bed form.
The first and second vents may be connected together via ducting or
passageways through the bed form. Alternatively, the bed form may
comprise a hollow shell so that the vents communicate via the
chamber within the hollow shell.
[0009] This arrangement will tend to create a standing wave at the
leading end of the bed form and any subsequent bed form. The
provision of a secondary flow channel within the bed form
communicating with a vent at the trailing edge of the bed form will
enhance production of a stable standing wave at the next bed form
in the channel, where two or more successive bed forms are
provided. A secondary flow passageway may also be provided in the
weir. In the exemplary embodiment, the side walls of the channel do
not extend vertically upwardlyfrom the top of the bed forms, but
instead have outwardly angled, shallow inclined portions which
taper slowly upwardly from the opposite sides of the weir and bed
forms. Alternatively, the side portions on opposite sides of the
channel extend outwardly either horizontally or at a slightly
downwardly inclined angle on opposite sides of the channel
containing the bed forms. In practice, the outer side portions or
side walls may extend outwardly from the channel at an angle
relative to the horizontal of +10.degree. to -5.degree.. This has
been found to enhance the standing wave formation capabilities of
the apparatus, and also provides a shallow lead-in portion for
individuals prior to riding a standing wave, and for exiting the
ride.
[0010] Water flows along the secondary flow passageway in either
direction, depending on the conditions. It has been found that the
provision of the secondary flow path enhances the formation of a
stable standing wave at the upstream face of the bed form, and at
any other bed forms downstream of the first bed form. Thus,
additional secondary flow passageways will be provided, one for
each wave-forming bed form. Adjustable valves or the like may be
provided in the secondary flow passageways in order to vary the
secondary flow rate. Additionally, several separate gates may be
provided across the width of the first vent or the flow passageway,
and these gates, if closed sequentially, can produce a lateral
breaking wave.
[0011] In an exemplary embodiment of the invention, the trailing
end of the bed form has an abrupt vertical drop off, such that the
uppermost region of the trailing end is raised up above the channel
bottom by a predetermined tail elevation. This has been found to
enhance the standing wave formation properties of the apparatus. In
fact, with an abrupt trailing end drop off in the waveform in a
predetermined elevation range, the secondary passageways may be
eliminated altogether, and standing waves may still be created. The
tail elevation factor (TEF), or ratio of the top surface distance
at the trailing end of the bed form above the channel bottom to the
elevation of the top or peak of the next bed form above the channel
bottom, may be in the range from 0.125 to 0.75 while still
producing a rideable standing wave. Waves will still be produced at
ratios above 0.75.
[0012] The tail elevation need not be constant across the entire
width of the bed form. For example, TEF may be zero at one side of
the channel and 0.8 at the other side. The tail elevation may be
permitted to self-adjust based on water pressure. This will produce
an oscillating wave.
[0013] In an exemplary embodiment of the invention, a series of
identical bed forms are provided at spaced intervals along the
channel, so that a series of standing waves may be formed. The
channel cross section may be deeper in the wave forming area than
at the outer sides of the bed forms, and may have gradually
outwardly sloping side walls. This tends to return water to the
center of the flume or channel, and also prevents too much water
from escaping around the sides of the bed forms.
[0014] According to another aspect of the present invention, a
method of forming waves is provided, which comprises the steps of
directing water from a reservoir at one end of a channel having a
base and spaced side walls into the channel and over a weir at the
inlet end of the channel, directing water in the channel in a
primary flow path over at least one bed form in the channel
downstream of the weir, the bed form having a leading end and a
trailing end, an upwardly inclined upstream face extending
downstream of the leading end, an upper portion, and a downwardly
inclined downstream face extending from the upper portion to the
trailing end, and directing a secondary flow of water along a
secondary flow passageway having a first end communicating with the
primary water flow at a location adjacent the trailing end of the
bed form, and a second end communicating with the primary water
flow at a location upstream of the first end, whereby a stable
standing wave is formed downstream of the bed form.
[0015] The apparatus and method of this invention may be modified
in order to create a standing curling wave or tubing wave. In one
embodiment, an oblique shaped bedform is positioned in the channel
at a position where a standing curling wave is desired. This gives
the water a sideways velocity component that induces the more
downstream side to break continuously while the more upstream side
remains an unbroken standing curl. Alternatively, another channel
may intersect the end of the primary channel at an oblique angle,
with a deeper river flow along the secondary channel. A curling
wave is created at the confluence of the faster, primary channel or
flume flow and the deeper river flow.
[0016] This invention provides a wave generating apparatus and
method particularly suitable for use in water park rides and the
like which is able to produce more consistent and controllable
standing waves than was possible in the past. The waves will be of
good quality, enabling surfers to ride for a longer period of time
without the wave decaying.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The present invention will be better understood from the
following detailed description of some exemplary embodiments of the
invention, taken in conjunction with the accompanying drawings in
which like reference numerals refer to like parts and in which:
[0018] FIG. 1 is a top plan view of a wave forming apparatus
according to a first exemplary embodiment of the invention;
[0019] FIG. 2 is a sectional view taken along lines 2-2 of FIG. 1,
showing the basic water flow;
[0020] FIG. 3 is a sectional view similar to FIG. 2, showing a
modified apparatus;
[0021] FIG. 4 is a sectional view similar to FIGS. 1 and 2
illustrating another embodiment of the wave forming apparatus;
[0022] FIG. 5 is an enlarged sectional view taken on lines 5-5 of
FIG. 2:
[0023] FIG. 6 is an enlarged sectional view similar to FIG. 2
illustrating another embodiment of the invention, with flow control
mechanisms;
[0024] FIG. 7 is a sectional view of a single bed form forming part
of a modified wave forming apparatus;
[0025] FIG. 8 is a sectional view illustrating another modified bed
form with vent height adjustability;
[0026] FIG. 9 is an end view of the bed form of FIG. 8,
illustrating the height adjusters across the width of the vent;
[0027] FIG. 10 is an enlarged sectional view similar to FIG. 6,
illustrating another embodiment of the wave forming apparatus;
[0028] FIG. 11 is a view similar to FIG. 10 illustrating another
embodiment of the invention;
[0029] FIG. 12 is a view similar to FIGS. 10 and 11, illustrating
another modified embodiment of the invention;
[0030] FIG. 13 is a view similar to FIG. 7, illustrating an
alternative flow control;
[0031] FIG. 14 is a sectional view on the lines 14-14 of FIG.
13;
[0032] FIG. 15 is a top plan view of a wave forming apparatus
according to another embodiment of the invention;
[0033] FIG. 16 is a sectional view on lines 16-16 of FIG. 15,
illustrating the water re-circulation path; and
[0034] FIG. 17 is a sectional view similar to FIG. 5, but on a
reduced scale, illustrating alternative side portions at opposite
sides of the wave forming channel.
[0035] FIG. 18 is a top plan view of a wave forming apparatus
according to another embodiment of the invention, for forming a
standing, curling wave;
[0036] FIG. 19 is a cross-sectional view on the line 19-19 of FIG.
18;
[0037] FIG. 20 is a top plan view of an alternative wave forming
apparatus for forming a standing, curling wave;
[0038] FIG. 21 is a sectional view on the line 21-21 of FIG.
20;
[0039] FIG. 22 is a sectional view on the line 22-22 of FIG.
21;
[0040] FIG. 23 is a top plan view of a modified wave forming
apparatus which is self-circulating;
[0041] FIG. 24 is a top plan view of a wave forming apparatus
according to another embodiment of the invention, in which the
primary flume is curved to create a standing, curling wave;
[0042] FIG. 25 is a sectional view on the line 25-25 of FIG. 24,
illustrating the exit area of the apparatus of FIG. 24;
[0043] FIG. 26 is a top plan view of a river type wave forming
apparatus according to another embodiment of the invention; and
[0044] FIG. 27 is a sectional view on the line 27-27 of FIG. 26;
and
[0045] FIG. 28 is a sectional view illustrating a modified wave
forming apparatus with a downwardly inclined bed.
DETAILED DESCRIPTION OF THE DRAWINGS
[0046] FIGS. 1,2 and 5 illustrate a wave forming apparatus
according to a first embodiment of the invention for forming
rideable, standing waves. The apparatus basically comprises a
channel 10 for containing a flow of water, the channel having a
weir 12 at its inlet end connected to a supply of water in a
reservoir 14, and a series of spaced bed forms 15 in the channel
downstream of the weir. Sloping side walls or entry/exit portions
16 extend outwardly from opposite sides 17 of the wave forming
channel 10 to the outer sides 18 of the apparatus, which are spaced
outwardly from the outer sides of channel 10, as best illustrated
in FIGS. 1 and 5.
[0047] As best illustrated in FIG. 2, the channel 10 has a base or
lower wall 20 and the weir 12 and bed forms 15 are provided at
spaced intervals along the channel, mounted in the base of the
channel and extending between the opposite side walls of the
channel, to define a primary flow path for water over the weir and
the bed forms. In the embodiment of FIGS. 1,2 and 5, the opposite
sides 17 of the channel 10 are shown to taper outwardly from the
inlet end of the channel, at weir 12, to the opposite end of the
channel. However, the sides 17 may alternatively be straight, as in
the embodiment of FIGS. 15 and 16, discussed in more detail below,
or taper inwardly.
[0048] The bed forms 15 are each of similar or identical shape and
have a leading end 22 and a trailing end 24, with an upstream face
25 inclined upwardly to a peak or upper portion, and a downstream
face 26 with a downwardly inclined, convex curvature extending from
the peak towards the trailing end 24. As best illustrated in FIG.
2, the upstream end 22 is flush with the base 20 of the channel,
for improved safety. The downstream face has a re-curve or change
in curvature adjacent the trailing end, such that it terminates in
a generally flat or horizontal portion 28. The trailing end 24 is
spaced above the base 20 of the channel to form an abrupt vertical
cut-off, as indicated in FIG. 2. The tail elevation factor TEF, or
ratio of the height h1 of the trailing end 24 of the bed form above
the base of the channel to the height h2 at the top or peak of the
next bed form is designed to be in a predetermined range which has
been found to produce standing waves. The range in TEF may be in
the range from 0.125 to 0.75 while still producing rideable
standing waves.
[0049] The weir 12 also extends upwardly from the base, with a
trailing end at the inlet from reservoir 14. Spaced inlet side
walls 30 extend from a location in reservoir 14 outwardly along
opposite sides of weir 12. This has been found to smooth the water
flow from the reservoir into the channel 10. The weir 12 is of an
airfoil like shape, extending upwardly from the leading edge to a
peak and then having a convex downward curvature up to trailing
edge 32, which is also spaced above the base 20 of the channel.
[0050] In the embodiment of FIG. 2, the weir and bed forms 12 and
15 may be of any suitable sheet material construction, such as
metal, strong plastic material, or thin concrete and have a hollow
interior. The bed forms each have a pair of elongate side vents 34
along opposite sides of the bed form extending across the peak of
the bed form, as best illustrated in FIGS. 1 and 2. Similarly, the
weir 12 has a pair of elongate side vents 35 on its opposite sides,
extending along part of the downwardly inclined face. The raised
trailing ends of the weir and bed forms also each form a vent 36
extending across the width of the channel, which defines, together
with side vents 34, a secondary flow path for water traveling along
channel 10.
[0051] The weir and bed form may each be supported by pedestals
under or adjacent the peak or highest point of the bed form, such
as pedestals 42 as illustrated in FIG. 2. Shorter pedestals 44 are
provided to support the tail end portion of the weir and bed forms.
The pedestals 42 and 44 are adjustable in height, with the opposite
sides of the weir and bed forms sliding against the channel side
walls 17. In an exemplary embodiment, two spaced pedestals 42 and
two spaced pedestals 44 are provided, with each pedestal being
approximately one quarter of the bed form width inwardly from the
adjacent side wall 17, and spaced apart from the other pedestal by
a distance equal to half the bed form width. A greater number of
pedestals may be provided if required for additional support.
[0052] In order to provide adjustability in the secondary flow, the
adjustable pedestals or hydraulic rams 42 and 44 provide height
adjusters for varying the bedform and tail elevation. In the
illustrated embodiment, the weir and bed forms are each secured to
the channel base at the leading end via a first pivot 38, and a
trailing end portion of the weir and bed forms is formed as a
separate section pivoted to the remainder at a second pivot 40. The
first pedestal or hydraulic ram 42 acts between the base of the
channel and the upstream pivoted portion of the weir and bed form,
and the second pedestal or hydraulic ram 44 acts between the base
of the channel and the pivoted trailing end portion of the weir and
bed forms. The first height adjuster 42 will change the height of
the peak of the weir or bed form, while the second height adjuster
will change the elevation of the tail end of the weir or bed form,
thus changing the vent height and the amount of secondary flow into
or out of the tail end vent. The two pedestals can therefore be
adjusted to vary the TEF ratio.
[0053] FIGS. 8 and 9 illustrate a modified height adjustment
mechanism for a bed form 15. In this case, rather than pivoted
sections, each bed form is a hollow shell 45 formed from a flexible
material and secured to the base 20 of the channel at the leading
end 46 only. A first series of spaced height adjusters or hydraulic
rams 48 extend at spaced intervals across the channel between the
base of the channel and the inner surface of the shell 45 adjacent
the peak of the bed form. A second series of spaced height
adjusters or hydraulic rams 50 extend at spaced intervals across
the width of the bed form adjacent the trailing end 52. Thus, the
height adjusters 50 can be extended by different amounts, as in
FIG. 9, in order to vary the height of the secondary passageway
vent 54 across the width of the channel, to vary the standing wave
properties. Useful waves can be created with different elevations
across the width fo the tail, for example one side may be at TEF=0
and the other side at TEF=0.8. This will still create a rideable
wave. If the rams 50 are eliminated, the tail end of the bed form
in FIG. 8 will be self-adjusting in height. This will create an
oscillating wave which may be desirable in some cases.
[0054] Although the embodiments of FIGS. 1,2 and 5 and FIGS. 8 and
9 have both weirs and bed forms with height adjustment devices, it
will be understood that the apparatus may alternatively have fixed
weirs, without any height adjusters, combined with adjustable bed
forms, or may have both fixed weirs and fixed bed forms of the same
general shape illustrated in the drawings. The adjustability is
provided as a means for the operator to vary the wave conditions as
desired. However, this may not be necessary in all cases. In
general, the height h2 of the peak of the bedform is in the range
of half of the inner flume height to 11/2 times the inner flume
height. In FIG. 5, the bedform height is approximately equal to the
inner flume height. The inner flume height will be dependent on the
application requirements, and in a water park attraction will be
around 1/6 of the width of the flume.
[0055] In the apparatus illustrated in FIGS. 1,2 and 5 and the
alternative of FIGS. 8 and 9, water will flow from the reservoir in
a primary flow path over the top of weir 12 and over each of the
successive bed forms. At the same time, as indicated by the arrows
55, a secondary flow path is provided via the side vents and
trailing end vents of the weir and bed forms. This secondary flow
may be in either direction, i.e. from the trailing end back under
the bed form and out at the peak of the bed form, or vice versa,
depending on overall flow conditions. The provision of a secondary
flow passageway through the bed form with a vent at the trailing
edge of the bed form has been found to produce a stable standing
wave 56 at the upstream face of the next bed form in the channel,
as indicated in FIG. 2. The standing wave formation is enhanced by
the provision of the shallow sloping side wall portions 16, which
provide for some flow outside channel 10, as indicated in FIG. 1.
In general, it is desirable that the flume be deeper in the channel
or wave forming area 10 that contains the bed forms, and shallower
just beyond the sides of the bed forms. This channels the water
over the bed forms, and prevents too much water from escaping
around the bed forms, while allowing the sides of the top portion
of the standing wave to vent sideways. This is believed to help
prevent the standing wave from decaying. The slight upward
inclination out to the opposite sides 18 of the apparatus also
helps to return water towards the center of the channel, helping
additional wave formation at subsequent downstream bed forms.
[0056] Although the opposite side portions 16 extending from
opposite sides of the channel 10 and bed forms out to the outer
sides 18 of the wave forming apparatus are shown in FIG. 5 as
having a slight upward slope, they may alternatively be flat or
even have a slight downward slope, as indicated in FIG. 17. FIG. 17
is a view similar to FIG. 5 of a modified flume structure in which
flat, shallow outer side portions 58 are provided on opposite sides
of the channel. The side portions 58 may alternatively be inclined
slightly downwardly, as indicated in dotted outline. It has been
found that the side portions 16 or 58 may have an inclination in
the range from -5.degree. up to +10.degree.. Any angle in this
range will have the desired effect of standing wave formation,
although an inclination above 0.degree. has the advantage of
returning water back into the channel downstream of a first
standing wave. Each side portion 16, 58 will have a width equal to
at least 33% of the channel width for optimum wave sustaining
effect. If the side portions are of different widths, one side may
have a width of 25% of the channel width if the other side is
wider.
[0057] The reservoir 14 will be continuously supplied with water
via a suitable water-recirculating system of a type well known in
the field of water park rides, in which water leaving the end of
channel 10 is pumped back into the reservoir. The water
re-circulation path may be beneath the channel 10, around one or
both sides of the channel, or from other adjacent, linked
rides.
[0058] The combination of features in FIG. 2, i.e. the specific bed
form shape, the secondary passageways, and the shallow outer side
portions 16, has been found on testing to lead to stable standing
wave formation. This, in turn, will produce a wave riding water
ride suitable for a water amusement park. The shallow outer side
portions 16 also provide a convenient means for a rider to enter
and exit the ride. It will be understood that the side vents 34,35
and end vents 36 will be covered with gratings (not illustrated)
for rider safety. The standing wave 56 will have a steep, unbroken,
and stable wave face which is ideal for surfing. Variation of the
trailing end vent height across the width of the bed form, as in
FIG. 9, may be used, if desired, to create effects such as a
sideways breaking wave. The height adjusters 42,44 may be adjusted
to produce a desired sequence of standing, stable waves.
[0059] The weir and bed forms of FIGS. 2 and 8 are hollow shells
which provide the secondary passageways back under the shell via
suitable venting. Although the vents 34,35 are spaced side vents in
the illustrated embodiment, a vent extending across the top of the
bed form may alternatively be provided. However, side vents will
normally be preferable since this avoids the need for a safety
grating across the entire top of the bed form. Additionally,
instead of forming the weir and bed forms by separate shaped
sheet-like members secured in the channel, they may alternatively
be formed or molded integrally in the base of the channel as solid
structures. FIG. 3 illustrates a modified wave forming apparatus
according to another embodiment of the invention, in which the
hollow shell weir and bed forms are replaced with a solid weir 60
and solid bed forms 62 spaced downstream of weir 60. The remainder
of the apparatus, apart from the weir and bed forms, is identical
to that of FIGS. 1 and 2, and like reference numerals have been
used for like parts as appropriate.
[0060] The weir 60 is of identical surface shape to the hollow weir
12 of FIG. 2, but has a passageway 64 extending under the weir from
the leading end to the trailing end 65, instead of the vent
structure of FIG. 2. The bed forms 62 are also of identical shape
to the bed forms 15 of FIG. 1, but the vent openings 34,36 are
replaced with passageways 66 through the bed forms. Each passageway
66 has one end opening 68 at the trailing end of the bed form, and
another end opening 69 adjacent the peak of the bed form. Two
openings 69 may be provided on opposite sides of bed form 62, with
two spaced passageways 66 ending in a chamber extending across the
width of the bed form and terminating at opening 68. Alternatively,
a single opening 69 and passageway 66 may be provided. This
arrangement will produce standing waves in an identical manner to
the previous embodiment.
[0061] FIG. 4 illustrates another modified embodiment, which has a
similar solid weir and bed form arrangement to FIG. 3, but the
secondary flow passageways are eliminated altogether. The structure
in FIG. 4 is again identical to that of FIGS. 1 and 2, apart from
the weir and bed forms, and like reference numerals are used for
like parts as appropriate. In FIG. 4, a weir 70 is provided at the
inlet end of channel 10 adjacent the reservoir outlet, and a series
of spaced, solid bed forms 72 of identical shape are provided along
channel 10 downstream of the weir. The weir 70 is of similar,
airfoil shape to the weir 60 of FIG. 4, but rather than having an
abrupt vertical cut off at the trailing edge, the trailing edge 74
of weir 70 continues to curve downwardly to meet the floor or base
20 of the channel at a smooth transition.
[0062] The bed forms 72 are of similar or identical shape to the
bed forms 15 and 52 of the previous embodiments, with a leading
edge 75 which has a flush transition with the base 20 of the
channel, an upwardly inclined leading face 76, a peak 77, a
downwardly inclined, concave trailing face 78, and a re-curved,
substantially flat trailing end portion 80 with an abrupt vertical
drop off face 82 at the trailing end of the bed form. It has been
found that an abrupt drop off, such as vertical face 82 or the
trailing end drop offs of FIGS. 2 and 3, helps to create a stable
standing wave at the leading face of the next bed form. This effect
will even occur without the secondary flow passageways, which is a
simpler and less expensive structure, although it is less easily
controllable and cannot be adjusted to produce different wave
forms.
[0063] In the embodiments of FIGS. 1 to 5, the bed forms each have
an abrupt trailing edge vertical drop off, with the trailing end of
the bed form raised above the channel by a predetermined height,
either with or without secondary flow paths for water through the
bed form. FIG. 6 illustrates another alternative embodiment which
has secondary water flow passageways, but no vertical drop off at
the trailing edge of the weir or bed forms. Other parts of the wave
forming apparatus are otherwise identical to the previous
embodiments, and like reference numerals have been used as
appropriate.
[0064] In the embodiment of FIG. 6, the channel 10 has a shaped
weir 84 at the entry or reservoir end, and one or more bed forms 85
at spaced intervals downstream of weir 84. The weir and bed forms
are of hollow shell construction, as in FIGS. 1 and 2, but may
alternatively be of solid construction with formed passageways, as
in FIG. 3. The weir is of generally airfoil like shape, and has a
curved, convex trailing face 86 which extends down to merge
smoothly with the base 20 of the channel at its trailing end 88. A
secondary passageway 90 extends from reservoir 14 through the lower
part of the weir up to the trailing end 88, with a safety grating
92 covering the open, trailing end of passageway 90. The passageway
90 may be provided with one or more flow control devices, such as
height adjuster or hydraulic ram 94 and flap valve 95. The
adjustable weir 84 of FIG. 6 may used in place of weir 12 of FIG.
2, or in any of the other embodiments to provide added
adjustability of water flow at the leading end of the channel.
[0065] The bed form 85 has a shape similar to bed form 15 of FIG.
1, with a generally concave, upwardly inclined leading face 96
leading up to a peak, and a downwardly inclined, generally convex
trailing face 97. However, the shape at the trailing end is
different from the previous embodiments, since the trailing end cut
off is eliminated, and the trailing face instead curves smoothly
down to meet the base 20 of the channel at its trailing end 98. As
in the previous embodiments, a secondary water flow passageway is
provided through the bed form 85 via a vent opening 100 at the
trailing end and vent openings 102 on opposite sides of the bed
form which extend over the peak of the bed form. The vent openings
will be covered with gratings for safety.
[0066] In this embodiment, the secondary passageway through the bed
form, along with the shallow side portions 16 on opposite sides of
the deeper channel containing the bed forms, and the shape of the
bed forms, will tend to create a standing wave 104 at the first bed
form 85 and each subsequent bed form in the channel, as in the
previous embodiments. It will be understood that the weir and bed
forms may alternatively be of solid construction with through
passageways, as in FIG. 3.
[0067] FIG. 7 illustrates an alternative bed form structure 110
which may be used in place of the bed forms 15 of the first
embodiment. In this case, rather than permitting flow circulation
in the entire area under the bed form, the flow is channeled
through one or more passageways 112 via a vent or slot 114 at the
trailing end of the bed form, and a vent or slot 115 adjacent the
peak of the bed form. Each vent 114,115 and the associated
passageway 112 may extend across the width of the bed form, or two
side slots may be provided as in FIGS. 1 and 2 to communicate via
spaced passageways with a full width vent 115. Flow control flaps
or valves 116 are provided in the passageway 112 to control the
secondary flow, so that the size and stability of the subsequent
standing wave can be controlled more readily.
[0068] FIG. 10 illustrates a wave forming apparatus according to
another embodiment of the invention, in which the weir 118 and bed
forms 120 are actually molded into the base 121 of the channel, out
of concrete or the like. The weir 118 has a passageway 122
extending from the leading end to a trailing end vent covered with
a pivoted grating flap 125 which rests freely against the base 121.
The upper portion 126 of the weir is pivoted at its leading end via
pivot 128 and supported adjacent its trailing end by one or more
hydraulic rams 130 spaced across the width of the passageway 122,
acting between the base 121 and portion 126. Thus, the secondary
flow rate can be readily adjusted simply by extending or retracting
ram 130, either lifting the free end of portion 126 to increase the
size of vent opening 124, or lowering portion 126 to reduce the
vent size.
[0069] The bed form 120 is of similar shape to the previous
embodiments, and has a secondary flow passageway 132 extending from
a location adjacent the peak or highest point of the bed form to
the trailing end of the bed form, wherein the vent is again covered
with a pivoted grating flap 134 permitting height adjustment. An
upper portion 135 of the bed form 120 is pivotally mounted at its
leading end via pivot 136, and supported at its trailing end by one
or more hydraulic rams 138 spaced across the width of the bed form,
extending between base 121 and the portion 135. Again, this permits
the size of the trailing end vent, and thus the amount of secondary
flow in either direction through channel 132, to optimize the
standing wave 139.
[0070] FIG. 11 illustrates an alternative embodiment in which both
the weir 140 and bed forms 142 have secondary flow passageways 144
extending from the leading end to the trailing end. Each passageway
144 has a flow control valve 145 for adjusting the amount of
secondary water flow. The vent openings at each end of the bed form
passageways, and the trailing end of the weir passageway, are
covered with safety gratings. The bed forms are of similar shape to
the previous embodiments, and will be mounted in an apparatus
similar to that illustrated in FIGS. 1 and 2, with shallow side
portions outside the channel containing bed forms 142. As in the
previous embodiments, the arrangement is such that rideable
standing waves 146 will form adjacent the peak of the first bed
form 142 and each subsequent bed form.
[0071] FIG. 12 illustrates another modification in which a weir 148
is followed by subsequent bed forms 150 of similar shape to the
previous embodiments. However, in this case, rather than providing
a secondary flow passageway extending from the peak or leading end
of the bed form to the trailing end of the bed form, secondary
water flow is instead provided via a vent passageway or opening 152
located between each adjacent pair of bed forms, and between the
weir and first bed form.
[0072] The passageways 152 are each covered by a safety grating 153
at their open end and communicate with a single through passageway
154 extending through the base of the channel beneath the bed
forms. A first portion 155 of the passageway beneath the weir is
cut off from the subsequent portion of the passageway extending
beneath the bed forms via wall 156. A flow control valve 158 is
provided at the junction between each vent passageway 152 and the
base passageway 152. This arrangement will also permit standing
waves to form by permitting flow into and out of the area beneath
the standing wave.
[0073] The embodiment of FIG. 12 will also be incorporated in an
apparatus as generally illustrated in FIG. 1 with a central, deeper
channel containing the weir and bed forms, and shallow side
portions on each side of the channel. The valves 158 provide
additional control for adjusting the properties of the standing
waves formed over the bed forms.
[0074] FIGS. 13 and 14 illustrate another modified bed form 160
which may be used in place of the bed forms 15 of FIGS. 1 and 2 in
a wave forming apparatus. The apparatus is otherwise identical to
that of FIGS. 1, 2 and 5, and like reference numerals have been
used for like parts as appropriate. In FIG. 13, the bed form is of
similar shape to that of FIG. 6, although it may have a shape
similar to that of FIG. 2, with a re-curved trailing end and a
sharp vertical drop off. A secondary flow passageway 162 is
provided from a vent opening or slot 164 at the peak of the bed
form to a trailing end vent 165 covered by a grating. The trailing
end vent 165 extends across the full width of the bed form, as
indicated in FIG. 14.
[0075] A series of flap valves 166 are provided across the width of
passageway 162 adjacent the trailing end vent opening. This allows
the opening size to be varied across the width of the vent 165, to
produce various effects in the subsequent standing wave formed
downstream of bed form 160. For example, by closing the flaps 166
successively across the width of the vent 165, a sideways breaking
wave may be produced. With all the flaps open, a stable standing
wave is produced.
[0076] FIGS. 15 and 16 illustrate a wave forming apparatus similar
to that of FIGS. 1,2 and 5, but showing a possible water
re-circulation system for circulating water back to a reservoir at
the inlet end of the apparatus. In this embodiment, a raised
reservoir 170 at one end of the apparatus supplies water via an
elongated inlet 172 to a wave forming channel 174 in which a weir
175 and a series of spaced bed forms 176 are provided. At the end
of channel 174, water falls through grating 178 into a chamber 180,
and is then re-circulated through a passageway 182 beneath channel
174 back to a chamber 183 beneath the reservoir, where it is
re-circulated via pumping system 184.
[0077] It will be understood that other water re-circulation
systems may be used, such as passageways around the sides of
channel 174, or the outlet end of the wave forming apparatus may be
connected to other water rides, and water may then be re-circulated
from those rides back to reservoir 170. As in the first embodiment,
shallow side portions 185 extend from each side of channel 174 to
the outer sides 186 of the apparatus, and this may be inclined
slightly upwardly, as in FIG. 5, or may be flat or inclined
slightly downwardly. The bed forms 176 of FIG. 16 are solid shaped
members similar to those of FIG. 4, without any secondary flow
passageways but with an abrupt vertical cut off 188 at the trailing
end. However, bed forms 176 may be replaced with any of the other
alternative bed forms illustrated in FIGS. 1 to 14. The sides of
channel 174 are straight, rather than flaring outwardly as in FIG.
1. However, they may alternatively taper outwardly or inwardly from
the leading end to the trailing end of the channel.
[0078] In this apparatus, as in the previous embodiments, standing
waves will be formed downstream of each waveform 176 at the next
structure, i.e. the upstream face of the next successive waveform,
or, in the case of the last waveform, at the upwardly inclined
grafting 178. The formation of a standing wave over grafting 178
has some advantages. For example, after exiting the wave, the rider
can easily stand up in the shallow water over the grafting in order
to exit the ride. In another alternative embodiment, a wave forming
apparatus may comprise a channel as in the previous embodiments
with a series of alternating waveforms and graftings, with each
wave being formed over a grafting. This will separate the riders
more effectively. Each successive waveform and grafting may be
stepped down from the preceding pair, to ensure adequate water flow
through the channel.
[0079] In each of the above embodiments, water flows over and
through a weir at the inlet end of the channel. However, flow may
alternatively be provided through side channels extending along
opposite sides of the weir, under the control of flap valves.
[0080] The wave forming apparatus in each of the above embodiments
will create a high quality, more readily controlled standing waves.
A combination of features produces the optimum wave conditions,
with some or all of these features being used dependent on the
desired form of the standing wave, and what degree of adjustability
in the wave formation is required. One key feature is a sequence of
two or more shaped bed forms, such that waves will tend to be
formed at a leading face of the successive bed forms. However, this
alone is not sufficient to form a stable standing wave. Another key
feature in forming a standing wave is the provision of secondary
flow beneath each bed form, with a vent for flow into or out of the
secondary passageway immediately upstream of the desired wave
forming location, prior to the leading face of the next bed form.
This is believed to provide flow out of or into the space beneath
the wave at the wave forming location, enhancing the stability of
the wave.
[0081] The opposite end of the secondary passageway is provided in
most cases at or adjacent the peak or highest point of the bed
form, and may comprise a vent across most of the width of the bed
form, or two elongated side vents on opposite sides of the bed form
centered at the peak. A further feature which produces improved
standing waves is the provision of a sharp, vertical cut off at the
trailing end of the bed form, so that a trailing end is spaced
above the floor of the channel. This alone, without a secondary
passage, will result in some standing wave formation. However,
standing waves are enhanced by providing both a secondary
passageway and a sharp cut off, as in some of the embodiments
illustrated above. The secondary passageway also provides a
convenient means for adjusting the standing wave, by means of
height adjusters to vary the height of the trailing end of the
waveform, valves to vary the secondary flow, and the like, as
illustrated in some of the above embodiments. Adjustment of the
size of the trailing end vent across the width of the bed form may
be used to create a breaking, curling, or pitching wave. A surge of
secondary flow can be created by hinging the bed form so as to
first cut off the secondary flow, and then lifting the trailing end
of the bed form. By providing a flexible trailing end portion for
the bed form, which can lift and lower freely based on flow
conditions, an oscillating wave form can be produced.
[0082] The bed form shape in each of the above embodiments
comprises a concave leading face, a curved peak, and a concave
trailing face. This tends to produce a wave at the leading face of
the next bed form. In some of the above embodiments, the trailing
face continues down to blend smoothly with the base of the channel.
However, wave forming is enhanced by providing a re-curve adjacent
the trailing end of the bed form, to produce a substantially
horizontal tail portion before an abrupt vertical drop off at a
predetermined tail elevation factor, or TEF, as illustrated in
FIGS. 2 to 4, 7, 8, 11, 12, and 16. This will even produce standing
waves without the secondary passageway for adding or removing water
beneath the formed wave, although optimum effects and adjustability
are provided by the combination of a secondary passageway and sharp
drop-off.
[0083] The flume cross-sectional profile in each of the above
embodiments comprises a deeper central channel containing the weir
and bed forms for producing waves, and shallower side portions
extending outwardly from opposite sides of the channel. This
channels the water over the bed forms and prevents too much water
from escaping around the bed forms, while allowing the sides of the
top portion of each standing wave to vent sideways. This helps to
prevent the wave from decaying and enhances stability. The shallow
side portions may be tapered slightly upwardly so as to return
water back to the center of the channel, although they may
alternatively be horizontal or tapered downwardly.
[0084] In the previous embodiments, the flume or channel is shown
as having a substantially flat or even bed or floor 20. However, it
may be beneficial in some cases, particularly in channels with a
plurality of bed forms for forming multiple standing waves, for the
floor 20 to have a slight incline downwards from the channel or
flume entrance to the end of the flume, as illustrated in FIG. 28.
This inclination may be in the range of 0 to 40. Rather than a
constant inclination along the length of the flume, it may have a
shallower portion extending from the entrance and a steeper portion
at the lower end, or it may be curved to provide a change in depth
along the flume.
[0085] FIGS. 18 and 19 illustrate a wave forming apparatus
according to another embodiment of the invention. This apparatus is
similar to the embodiment of FIGS. 1 and 2, and like reference
numerals have been used for like parts, as appropriate. However,
instead of a series of bed forms which are each perpendicular to
the water flow direction, in this embodiment the last bed form 200
in the channel or flume 10 is oriented at an oblique angle to the
water flow. Also, the floor 20 may have a slight declination of the
order of 1 to 40, as in FIG. 28.
[0086] As in the previous embodiments, channel 10 has a weir 12 at
its inlet end connected to a supply of water in a reservoir 14. A
first bed form 15 is positioned downstream of weir 12 in order to
create a stable, standing wave. Oblique bedform 200 is positioned
downstream of bedform 15. In alternative arrangements, a greater
number of bedforms 15 may be provided prior to oblique bedform 200.
The channel 10 is of tapering, gradually increasing width along its
length, and may be provided with a water re-circulation system at
its end as in FIGS. 15 and 16, or may intersect with another
channel in other arrangements. Sloping side walls or entry/exit
portions 16 extend from the opposite, vertical sides 17 of the wave
forming channel or flume 10 to the outer sides 18 of the
apparatus.
[0087] The weir and bed form 15, as well as the oblique bed form
200, are each of hollow shell construction, although they may be of
any of the alternative constructions illustrated in the preceding
embodiments. The bed forms 15 and 200 each incline upwardly to a
peak, and then incline downwardly to a trailing end 24,202 which is
raised above the bed or base 20 of the channel. An inclined grating
204,205 extends from the trailing end of each bed form down to the
base 20. Grating 206 is also provided over the open, trailing end
of the weir 12. The bed forms 15 and 200 each have a pair of
elongate side vents 34 along opposite sides of the bed form and
extending across the peak of the bed form. Similarly, the weir 12
has a pair of elongate side vents 35. The raised trailing end of
each bed form and the vents 34 together form a secondary flow
passageway for water through the bed form, as described in
connection with the previous embodiments.
[0088] The oblique bed form 200 in the illustrated embodiment has
an oblique or non-perpendicular leading edge 208 and a peak or
ridge line 210 which is at the same oblique angle as the leading
edge 208. The trailing edge 202 is shown at the same oblique angle
as the leading edge and peak, although it may be at a different
angle or even perpendicular to the flow. It is the angle of the
leading edge and peak which are critical in creating a standing,
curling wave or tube, and the orientation of the trailing edge will
be dependent on what waveforms, if any, are to be provided
downstream of the oblique bed form. It may also be advantageous to
rake the trailing edge 24 of the bed form 15 immediately upstream
of the oblique bed form 200 to provide the ideal hydraulic
conditions for standing wave formation, for example as illustrated
in dotted outline in FIG. 18. The angle of the leading edge 208 for
creating a curling wave is in the range of 15 to 30 degrees from
perpendicular to the flow direction, i.e. 105 to 120 degrees to the
flow direction. In the exemplary embodiment, as noted above, the
peak or ridge line 210 is at the same angle as leading edge 208,
but could vary from this angle in order to create different wave
effects.
[0089] In this embodiment, the first bed form 15 will create a
standing wave with a stable wake as described above, while the
oblique bed form will create a stable or standing curling wave. The
raked leading edge and slant of the bed form 200 will give water a
sideways velocity component which induces the more downstream side
to break continuously while the more upstream side remains an
unbroken standing wave. Thus, the curling wave will be created near
the downstream end of the bed form and will extend across the bed
form, as indicated in FIGS. 17 and 18. The water depth across the
wave will vary from channel flow depth just prior to the wave to
depths almost as high as the wave itself when measured under the
peak. The standing tube or curling wave is induced to pitch out
continuously by the bottom form of the bed and the ventilated shear
wake created by the wave forming structure.
[0090] All the motion controls applied to the normal standing wave
forming apparatus of the previous embodiments may be applied to the
oblique bed form for forming the curling standing wave. Thus, the
tail elevation, peak height, flow rate, channel depth, and other
parameters may be varied in order to vary the wave.
[0091] FIGS. 20 to 22 illustrate another embodiment of a wave
forming apparatus for creating a standing, curling wave. In this
embodiment, instead of providing an oblique bed form in the primary
channel 10, another channel 220 is oriented to intersect the end of
the primary channel 10 at an oblique angle. The water flowing in
the secondary channel or river 220 will be deeper than the water
flowing along primary channel 10, as indicated in FIG. 21. The
primary channel 10 will have a weir and a series of bed forms 15
for creating stable standing waves, as in the first embodiment,
with only the last bed form 15 being illustrated in FIGS. 20 and
21. The apparatus would also work with only one bed form 15 in the
primary channel or flume 10, if no additional standing waves are
desired.
[0092] A river bed form 222 is provided in the bed 224 of river or
secondary channel 220. River or secondary channel 220 has an inner
side wall 229 and an outer wall 230. The river is fed from a
suitable water supply such as a reservoir 231. The bed form 222 in
river 220 may be a solid or hollow bed form, and does not require
any secondary flow channels. The bed form 222 is of generally
rounded shape and is elongated in the river flow direction, as
indicated in FIG. 22, with gradually tapering or smoothly contoured
ends 225,226 merging smoothly with the river bed 224. The leading
surface 228 of the bed form 222 facing the primary channel 10 is of
convex, rounded shape, as best illustrated in FIG. 21. The leading
surface 228 will be similar in shape to the flume bed forms 15, and
the height of the bed form 222 is less than that of the flume bed
forms. The trailing surface shape is not critical and no tail
elevation is required, because no downstream wave will be created
after the curling wave. The bed form shape and length in the river
flow direction are not critical. Overall height, position, and
leading surface shape are the most critical factors. The ideal
position for bed form 222 is at the confluence of the two water
flows, but it may be adjusted upstream or downstream slightly for
different effects. As noted above, the leading surface shape will
be approximately the same as the leading surface shape of flume bed
forms 15, but the peak will be of lower height.
[0093] In this embodiment, a curling wave 232 is created at the
confluence of the faster flume flow exiting channel 10 with the
deeper and slower river flow along channel 222. A stable wake is
induced between bed form 15 and bed form 222. The combination of
the stable wake and confluence of the two water flows creates a
hollow curling wave suitable for riding in the tube of the wave.
This wave can be controlled to advance or recede using the motion
controls of the bed form apparatus, as described in detail in the
previous embodiments, as well as by changing the flow rates and
depths of the primary flume and/or river flow. The two reservoir
sources 14 and 231 will provide the proper flow rate and velocity
for each flow in order to create the standing, curling wave, and
may be adjusted as needed. The curling wave can also be induced to
break, advance, and recede by introducing traveling waves into the
primary channel or the river flows.
[0094] The curling wave 232 is created in part by the depth of the
water in the river behind the curling wave, or pooled water level,
and partly by the oblique angle of the intersecting flow. Typical
hydraulic jumps can be created by introducing faster moving water
into slower moving water. The ideal level for the pooled water or
intersecting river behind the curling wave 232 is a factor of 1.5
greater than the overall elevation drop from the channel base or
flume bottom 20 at the entrance to channel 10 down to the flume
bottom at the wave location. Adjusting the pooled water level
behind curling wave 232 will change the size and characteristics of
the curling wave. If the pooled water level is too high, say a
factor of 2 greater than the flume elevation drop, the pooled water
may cause the wave to decay. If the pooled water level falls to a
factor of 0.7 or less of the flume elevation drop, the wave will be
eliminated.
[0095] In an exemplary embodiment of the invention, the angle of
intersection between the water flows in the primary flume or
channel 10 and the river 220 was approximately 75 degrees (i.e. the
angle between channel 10 and river 220, but it may be in the range
from 30 degrees to 90 degrees. The range of suitable angles depends
in part on the velocities of the two flows. For example, two sheet
flows (flows with Froude numbers substantially in excess of 5, and
approximately 35 and higher in current sheet flow technology
practice) can be directed at each other to produce a water effect
with the appearance of a curling wave. Any practical angles other
than parallel can produce the effect. For standing wave formation,
the river flow is typically slower, at subcritical (Froude number
less than 1) or faster speeds, producing a hydraulic resistance to
the faster flume flow. This, together with the oblique angle of
intersection, tends to produce the standing curling wave, with the
wave breaking continuously at the downstream end of the
intersecting flows and the more upstream end forming an unbroken
standing wave. Bed form 222 enhances the standing, curling wave
formation. Flume water Froude numbers in the trough just ahead of
the standing wave have Froude values in the 1 to 5 range. With
standing waves, Froude numbers vary at every location in the flow
and are subcritical (less than 1) at the standing wave peak. The
river bed form 222 helps to control the position and formation of
the standing curling wave.
[0096] FIG. 23 illustrates a modification in which, rather than
having an independently fed intersecting river flow, as in FIGS. 20
to 22, a continuous loop 234 is provided, with the primary channel
10 intersection the inner wall 235 of the loop at the desired
oblique angle. This is a more efficient layout where the river flow
is created by the inertia of the flume flow driving the combined
flows in a continuous loop. For simplicity, the bed forms in
primary channel 10 and in the loop at the intersection 236 between
the primary channel and river flow are not shown, but will be
identical to those illustrated in FIGS. 20 to 22 in order to create
the standing curling wave 232, as well as one or more standing
waves in the primary channel 10.
[0097] FIGS. 24 and 25 illustrate another alternative arrangement
for creating a standing, curling wave. Instead of a secondary
channel or river loop intersecting the primary channel 10, in this
embodiment a primary channel 238 has a curve 240 immediately after
a standing wave producing bed form 15, inducing a sideways flow
component which will create a standing tubing wave 242. The water
depth is changed at the curve 240 by providing a weir 244 at the
outlet end of the channel which tends to back up water ahead of the
tubing wave 242, as indicated in FIG. 25. The weir 244 is provided
in the bottom or bed 245 of the channel 238 adjacent the end wall
246, and an outlet opening 248 allows water exiting the channel to
flow back along water return passage 250. An inclined safety grille
252 covers the weir 244 and exit opening 248. The weir 244 will
cause the water to back up, increasing the water depth and slowing
the flow rate, which enhances the tubing wave formation.
[0098] FIGS. 26 and 27 illustrate another alternative wave forming
apparatus in which jet pumps replace the reservoir in creating the
primary flume flow ahead of the bed forms. In this embodiment, the
flume or channel 260 is in the form of an elongated river loop,
with jet pumps 262 provided at the start of each straight side
portion 264 of the loop in the flow direction. One or more standing
wave forming bed forms 15 are provided in each straight side
portion 264, and these will have venting as in the previous
embodiments for creating standing waves. A second type of bed form
265 is provided at the start of each curled end 266 of the loop.
This will have no venting and will be shaped at its trailing end
268 to conform with the bend in the channel, as indicated in FIG.
26. The bed forms 265 are lower in height than the bed forms 15.
With this arrangement, one or more standing waves are produced at
bed forms 15, while a curling standing wave 270 is produced at each
curve or bend in the river loop.
[0099] The jet pump arrangement is illustrated in more detail in
FIG. 27. As illustrated, jet pumps 262 will be arranged in pairs
inside a housing having a flat upper wall 272, an inclined inlet
grille 274, and an inclined outlet grille 275. Water is drawn
through the inlet grille and out through the exit grille, as
indicated, in order to circulate water at the desired flow rate.
The river loop 260 may be elongated if a greater number of standing
wave bed forms 15 is desired.
[0100] The enhanced, stable, stationary wave formation of this
invention, as well as the standing curling wave formation of FIGS.
18 to 27, may have applications outside the field of water
amusement parks. For example, suitably shaped bed forms may be
provided at the spillway of a dam. This would allow for standing
wave creation which would spread energy more quietly and reduce the
mist that is produced in standard dam spillways. In turn, this
would reduce erosion. In another related application, this bed form
and flume technology can be provided in aqueducts and sumps to
remove sediment and prevent sediment accumulation. Another possible
application would be as a water based arcade attraction, of the
type using radio controlled boats or surfers. In this case, the
apparatus would be made at around one quarter of the normal water
ride scale. It may also be used in a stand-alone water toy. The
invention may also be used for a purely ornamental water attraction
in parks and the like.
[0101] Although some exemplary embodiments of the invention have
been described above by way of example only, it will be understood
by those skilled in the field that modifications may be made to the
disclosed embodiments without departing from the scope of the
invention, which is defined by the appended claims.
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