Abstract:
An adjustable physical structure for producing hydraulic formations for whitewater recreationalists includes a control structure, and an adjustable lip located downstream of the control structure. The control structure can include a crest and a ramp. The crest constricts and/or elevates (dams) the flow water to increase it&#39;s energy and focus the flow of water. Downstream of the crest, the ramp routes the flow of the water to the adjustable lip. The ramp can have varying and non-linear slopes and plan configurations. Additionally, the ramp can be static or adjustable to elevate the flow of water and vary the velocity and energy of the supercritical flow as it is passed to the adjustable lip. An adjustable invert physical structure comprises a shaped structure configured for placement on the invert of the channel. The adjustable invert physical structure can be moved or adjusted in horizontal and/or vertical directions to shape the flow of water.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This application claims priority from U.S. provisional application Ser. No. 60/854,747 filed Oct. 27, 2006. 

   BACKGROUND 
   Whitewater recreationalists are persons in or on a river, rapid, or flowing channel that use the currents and various hydraulic formations for recreation and enjoyment. This grouping of recreationalists is also referred to as “boaters” or “river runners”. There are many different types of whitewater craft that whitewater recreationalists can use to make their way down a river or rapid. An abbreviated list includes: 
   
     
       
             
             
             
             
           
         
             
                 
             
             
                 
                 
               Inflateable kayaks 
               Open-decked 
             
             
               Rafts 
               Kayaks 
               and other craft 
               Canoes 
             
             
                 
             
           
           
             
               Closed-decked 
               Dory or Drift 
               Personal Inflated 
               Catarafts 
             
             
               Canoes 
               Boats 
               Water Craft (“rubber 
             
             
                 
                 
               duckies”) 
             
             
               Wake boards &amp; 
               Swimmers with 
               Surfboards &amp; 
               Tubes 
             
             
               other small 
               or without fins, 
               Riverboards 
             
             
               boards used to 
               and paddles 
             
             
               assist 
             
             
               swimming 
             
             
                 
             
           
        
       
     
   
   Whitewater recreationalists include an increasing number of persons with disabilities including paraplegics, the blind, amputees, etc. Organized sports which involve or evolved from recreational whitewater include:
         Slalom: A competitive event for canoeing and kayaking where boaters negotiate gates suspended over the river for the fastest time.   Freestyle or Rodeo: A competitive event for canoeing and kayaking where boaters perform tricks on a wave, hole, or other hydraulic feature or obstruction.   Rafting: An event where rafters race down the river for the fastest time.   Down-River or Wildwater kayaking: An event where kayakers race down the river for the fastest time.   Squirt Boating: A competitive event where kayakers and canoeists perform tricks utilizing sub-surface current in low volume boats.       

   Open Channel Hydraulics is the formalized science that considers the formation of hydraulic formations that are encountered by whitewater recreationalists found in rivers and man-made structures. This includes those features associated with whitewater rapids and features. The basic equations governing whitewater hydraulic formations are the Navier-Stokes equations which are an application of Newton&#39;s second law. These can be reduced to simpler forms when considering the free (water) surface found in rivers and channels and the incompressibility of water. 
   Whitewater recreationalists refer to various hydraulic formations found in fast-moving rivers, rapids, and channels. These hydraulic formations include “Holes”, “Waves”, and “Hydraulics”. These describe various forms of what is referred to by scientists and engineers as a hydraulic jump. (Note however that waves can be formed by other hydraulic mechanisms.) A hydraulic jump occurs when fast moving flow in a state known as supercritical changes to a slower moving subcritical state. From a scientific point of view, supercritical flow is defined as having a Froude Number greater than one, and subcritical flow is defined as having a Froude Number less than one. The Froude Number is a well defined hydraulic term which is a dimensionless ratio of inertial forces to gravitational forces. The Froude Number is defined as V_√(gd), where V=velocity of the flow, g=gravitational acceleration, and d=characteristic depth. 
   The hydraulic jump was studied extensively in the 1950s and 1960s, although hydraulic jump formations involving non-linear channel geometries formations can be quite complex and difficult to analyze or predict—even with computer modeling. Physical structures that can create waves and holes with recreationally desirable attributes have a vertical or steep downward slope in the vicinity where the hydraulic jump occurs. This condition was studied in the 1950s and 1960s and is know as a hydraulic jump at an abrupt drop. 
   The abrupt drop can cause the hydraulic jump to stabilize in deeper areas, and create other characteristics that are advantageous to whitewater recreationalists. At an abrupt drop the transition from supercritical to subcritical flow is characterized by several flow patterns depending upon the inflow and conditions found in the downstream pool (tailwater). These flow patterns include (1) the A-jump, (2) the wave jump or W-jump or the wave train, and (3) the B-jump which is characterized by a plunging jet. The characteristics of wave jump and wave train are essentially the same and hereafter the wave jump and wave train will simply be referred to as ‘Wave’ 
   Holes and waves are often the predominant features treasured by whitewater recreationalists. Holes are more retentive—having tendency to impede the passage of buoyant objects, while waves create exciting changes in elevation. Waves known as “breaking waves” can also have breaking water (whitewater) toward their crest that acts to retain buoyant whitewater craft. The form and type of these hydraulic jumps varies dramatically and even small nuances not noticeable to the untrained eye can affect the desirability to whitewater recreationalists. 
   Pools are areas in a river or channel that move slowly (relative to the higher velocity rapids) in the downstream direction. They are typically in a hydraulic state known as subcritical—having a Froude Number less than a value of one. However higher velocity currents or jets can carry through the entire length of a pool. Pools can also have recirculating eddy currents known as “eddies”. Pools are advantageous to whitewater recreationalists for recovery. 
   Eddies are formed upstream and downstream of obstructions in a river. Eddies are generally recognized by whitewater recreationalists to occur in a pool adjacent to and downstream of a wave or hole. Eddies are currents that tend to rotate in the horizontal plane. This rotation can usually be seen on the surface of the water. Typically, the flow in an eddy is oriented upstream rather than downstream. An eddy can have slow or mild upstream currents or can be quite violent. The characteristics of an eddy are important to the recreational experience of whitewater recreationalists playing in an adjacent hydraulic jump. 
   Structures that create the various formations of the hydraulic jump including waves and holes tend to control and focus flow and/or lower the flow to increase it&#39;s velocity and power so that it is supercritical. This requires some type of crest, which usually has elevated portions to form a constriction. The flow in the vicinity of the physical crest—also known as a control section—typically enters a state known as critical depth. Note that at this location, the Froude Number of the flow has a value of one. Downstream of this crest is a ramp where the flow transitions from a critical state to supercritical state prior to entering the hydraulic jump. Note that some structures have an entirely vertical ramp; while in others; there is no clear physical distinction between the crest and the ramp. The ramp is simply where the flow transitions from the critical flow to the hydraulic jump. 
   A wave can also be created in situations where a hydraulic jump is not involved. Sometimes known as a wave train or standing waves, these can be created by a perturbation or series of perturbations or “bumps” in the invert of a river or channel. This type of wave, however, is difficult to reliably create or predict and usually occurs through very specific flow rates when found in natural rivers. 
   Typically, prior art man made physical structures for producing hydraulic formations have fixed geometries and fixed dimensions. One problem with these fixed physical structures is that they may not produce the desired hydraulic formations at normal or low water flow rates. In addition, at excessively high water flow rates, fixed physical structures may form constrictions, increased floodplains and high water surface elevations. 
   It would be advantageous for physical structures for producing hydraulic formations to have an adjustable geometry, which could be used to vary the size and character of the corresponding hydraulic formations over a wide range of water flow rates. It would also be advantageous for physical structures for producing hydraulic formations to be adjustable for constructing a variety of systems for whitewater recreationalists under a variety of conditions. 
   Various embodiments of adjustable physical structures to be further described can be used to form hydraulic formations. In addition, the adjustable physical structures can be adjusted to vary the geometry of the hydraulic formations, and can be used over a wide range of flow rates and environmental conditions. Further, the adjustable physical structures can be used to construct various systems including kayak courses, rafting courses, boating courses and theme park rides. 
   However, the foregoing examples of the related art and limitations related therewith, are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings. 
   SUMMARY 
   An adjustable physical structure is configured for placement in a channel containing a flow of water for producing a variety of hydraulic formations beneficial for whitewater recreationalists. The channel can comprise a man made channel, or a natural channel such as a river bed. The adjustable physical structure includes a control structure placed in the channel, and an adjustable lip located downstream of the control structure. 
   The control structure can include a crest and a ramp downstream of the crest. The crest constricts and/or elevates (dams) the flow water to increase it&#39;s energy and focus the flow of water. The crest can be curved, linear or irregular in both plan and in cross-section. The flow in the vicinity of the crest—also known as a control section—goes through a state known as critical depth. At this location, the Froude Number of the flow of water has a value of one. If present, the ramp routes the flow of the water to the adjustable lip. The ramp can have varying and non-linear slopes and plan configurations. Additionally, the ramp can be static or adjustable to elevate the flow of water and vary the velocity and energy of the supercritical flow as it is passed to the adjustable lip. 
   The adjustable lip is configured for placement at a selected position in the flow of water. For example, the adjustable lip can be adjusted vertically to vary the elevation and angle of supercritical flow as it exits the adjustable physical structure and enters a downstream pool where the flow transitions—via a hydraulic jump to subcritical flow. The adjustable lip can also be located downstream of a second adjustable plate(s), perforated plate(s), or series of vanes. The adjustable physical structure can also include an adjustable placement mechanism such as a cylinder, a bladder or a mechanical jack, which can be operated to place the adjustable lip in the selected position. 
   An alternate embodiment adjustable invert physical structure comprises a shaped structure configured for placement on the invert of the channel. The adjustable invert physical structure can be moved or adjusted in horizontal and/or vertical directions to shape the flow of water. 
   A method for forming hydraulic formations includes the steps of providing a flow of water in a channel; providing an adjustable lip configured for placement in a selected position in the flow of water; forming a drop upstream of the adjustable lip; accelerating the flow of water towards the lip; and adjusting a position of the lip in the flow of water to the selected position. 
   A whitewater system includes one or more adjustable physical structures and/or adjustable invert physical structures placed in a channel at desired locations, and configured to form desired hydraulic formations. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Exemplary embodiments are illustrated in the referenced figures of the drawings. It is intended that the embodiments and the figures disclosed herein are to be considered illustrative rather than limiting. 
       FIG. 1A  is a schematic plan view of a system for whitewater recreationalists constructed using adjustable physical structures for producing hydraulic formations; 
       FIG. 1B  is a schematic plan view of another system for whitewater recreationalists constructed using adjustable physical structures for producing hydraulic formations; 
       FIG. 2  is a plan view of an adjustable physical structure for producing hydraulic formations taken along line  2  of  FIGS. 1A and 1B ; 
       FIG. 2A  is a cross sectional view taken along section line  2 A- 2 A of  FIG. 2 ; 
       FIGS. 2B-2E  are plan views of optional wave shaper extensions for the adjustable physical structure of  FIG. 2 ; 
       FIGS. 2F-2I  are end views of the optional wave shaper extensions shown in  FIGS. 2B-2E ; 
       FIG. 2J  is a plan view of an optional lip block wave shaper; 
       FIG. 2K  is a cross sectional view of the lip block wave shaper of  FIG. 2J ; 
       FIG. 3  is a plan view of an adjustable through-flow physical structure taken along line  3  of  FIGS. 1A and 1B ; 
       FIG. 3A  is a cross sectional view taken along section line  3 A- 3 A of  FIG. 3  showing the adjustable through-flow physical structure in a raised position; 
       FIG. 3B  is a cross sectional view equivalent to  FIG. 3A  showing the adjustable through-flow physical structure in a lowered position; 
       FIG. 3C  is a schematic cross sectional view showing the operation of an adjustable lip of the adjustable through-flow physical structure; 
       FIG. 3D  is a cross sectional view equivalent to  FIG. 3A  showing the adjustable through-flow physical structure with an optional cover; 
       FIG. 3E  is a cross sectional view taken along section line  3 E- 3 E of  FIG. 3  showing the adjustable through-flow physical structure along side identical adjustable through-flow physical structure in phantom lines; 
       FIG. 4  is a plan view of an adjustable wing wall physical structure taken along line  4  of  FIGS. 1A and 1B ; 
       FIG. 4A  is a cross sectional view taken along section line  4 A- 4 A of  FIG. 4 ; 
       FIG. 4B  is a cross sectional view taken along section line  4 B- 4 B of  FIG. 4 ; 
       FIG. 5  is a plan view of an adjustable wing wall physical structure taken along line  5  of  FIGS. 1A and 1B ; 
       FIG. 5A  is a cross sectional view taken along section line  5 A- 5 A of  FIG. 5 ; 
       FIG. 5B  is a cross sectional view taken along section line  5 B- 5 B of  FIG. 5 ; 
       FIG. 6  is a plan view of an adjustable physical structure taken along line  6  of  FIGS. 1A and 1B ; 
       FIG. 6A  is cross sectional view taken along section line  6 A- 6 A of  FIG. 6 ; 
       FIG. 6B  is cross sectional view taken along section line  6 B- 6 B of  FIG. 6 ; 
       FIG. 7  is a plan view of an adjustable physical structure integrated into the outlet of a conveyance structure such a pump outlet. The section is taken along line  7  of  FIGS. 1A and 1B ; 
       FIG. 7A  is a cross sectional view taken along section line  7 A- 7 A of  FIG. 7 ; 
       FIG. 7B  is a cross sectional view taken along section line  7 B- 7 B of  FIG. 7 ; 
       FIG. 8  is a plan view of an adjustable physical structure with an expandable or flexible membrane taken along line  8  of  FIGS. 1A and 1B ; 
       FIG. 8A  is a cross sectional view taken along section line  8 A- 8 A of  FIG. 8 ; 
       FIG. 8B  is a cross sectional view taken along section line  8 B- 8 B of  FIG. 8 ; 
       FIG. 9  is a plan view of an adjustable invert physical structure taken along line  9  of  FIGS. 1A and 1B ; and 
       FIG. 9A  is a cross sectional view taken along section line  9 A- 9 A of  FIG. 9 . 
   

   DETAILED DESCRIPTION 
   Referring to  FIG. 1A , a whitewater system  10 - 1  includes various adjustable physical structures  12 A- 12 H which produce various hydraulic formations. By way of example, the whitewater system  10 - 1  can be part of a theme park or other attraction for whitewater recreationalists  11 . The whitewater system  10 - 1  ( FIG. 1A ) includes a man made channel  14 - 1  configured to contain a flow of water  16  in a closed loop as indicated by water flow direction  18 . The whitewater system  10 - 1  ( FIG. 1A ) is sized to allow one or more watercraft  19 , and swimmers as well, to ride on the flow of water  16  through the system  10 - 1 . The whitewater system  10 - 1  ( FIG. 1A ) can also include one or more pumps (not shown) configured to produce the flow of water  16 . A representative depth d of the flow of water  16  in the channel  14 - 1  can be from 4 inches to 10 feet. A representative flow rate of the flow of water  16  in the channel  14 - 1  can be from about 30 cubic feet per second (cfs) to 1000 cubic feet per minute (cfs). 
   Referring to  FIG. 1B , a whitewater system  10 - 2  containing adjustable physical structures  12 A- 12 H is illustrated. In this embodiment, the channel  14 - 2  can comprise a river bed, and the system  10 - 2  can form a whitewater course such as a slalom course, a kayak course, a rafting course or a boating course. 
   Referring to  FIGS. 2 and 2A , an adjustable lip physical structure  12 A is illustrated. The adjustable lip physical structure  12 A ( FIGS. 2-2A ) includes a crest  20 A, a ramp  22 A and an adjustable lip  24 A. The crest  20 A and the ramp  22 A form a control section in which the flow of water  16  is focused and increased in energy. The crest  20  ( FIGS. 2-2A ) is formed or placed on the invert  26 A (bottom) of the channel  14 - 1  or  14 - 2  oriented generally vertically, and generally perpendicular to the water flow direction  18 . The crest  20 A ( FIGS. 2-2A ), and the ramp  22 A as well, can be formed of a solid material such as concrete, rock, grouted rock or steel. The crest  20 A ( FIGS. 2-2A ) functions similarly to a dam, and is configured to focus and build up the water to form a hydraulic drop. The hydraulic drop is the difference in elevation between the water surface upstream and the water surface downstream of the adjustable lip physical structure  12 A. The height of the crest  20 A ( FIGS. 2-2A ) will be dependent on the depth d of the water in the channel  14  and the desired power, hydraulic formation, and recreational experience created by the physical structure. A representative depth dl ( FIG. 2 ) of the flow of water  16  above the top of the crest  20 A can be from 0.5 feet to 6 feet. A representative width of the crest  20 A, and the ramp  22 A and adjustable lip  24 A as well, can be from 6 feet to 30 feet. 
   The ramp  22 A ( FIGS. 2-2A ) comprises a sloped structure that can be formed continuously with the crest  20 A. The ramp  22 A ( FIGS. 2-2A ) is configured to accelerate the flow of water  16  from the crest  20 A downstream to the adjustable lip  24 A. The ramp also varies the velocity and energy of the flow of water  16  which preferably has a supercritical flow as it contacts the adjustable lip  24 A. As shown in  FIG. 2A , the ramp  22 A ( FIGS. 2-2A ) can slope downwardly from the upstream end to the downstream end of the adjustable lip physical structure  12 A. A representative slope of the ramp  22 A ( FIGS. 2-2A ) can be from 0.5 inches per foot to 12 inches per foot. The ramp  22 A can also have a shape which converges the flow of water  16  towards the adjustable lip  24 A, such that a more focused v-shaped hydraulic formation is produced. The ramp  22 A can also have a shape which diverges the flow of water  16  towards the adjustable lip  24 A such that a broader hydraulic formation is produced. 
   The adjustable lip  24 A ( FIGS. 2-2A ) comprises a generally l-shaped structure pivotably and adjustably mounted to a base  28 A ( FIG. 2A ). The adjustable lip  24 A is located on a stepped invert  26 A of the channel  14 - 1  ( FIG. 1A ),  14 - 2  ( FIG. 1B ) having a vertical drop  52 A. The adjustable lip  24 A can be formed of a material such as steel, and can be weighted with a material such as concrete, to resist the large hydraulic forces encountered during operation of the adjustable lip physical structure  12 A. As shown in  FIG. 2A , the adjustable lip  24 A can include a vertical member  38 A and a horizontal member  40 A, which can be welded or bolted together. The inside angle between the horizontal member and the vertical member can range from 90 degrees (as shown) to 160 degrees. As shown in  FIG. 2 , the adjustable lip  24 A can also include bracing members  42 A, and a pivot support member  44 A which pivotably mounts the adjustable lip  24 A to the base  28 A on bolts, pins or other mechanisms. 
   In  FIG. 2A , the adjustable lip  24 A is shown in three different positions (Positions  1 - 3 ) in the flow of water  16 . The adjustable lip  24 A can be locked in each of these positions (Positions  1 - 3 ) as well as any position in between. As also shown in  FIG. 2A , the position of the adjustable lip  24 A can be selected as required, from a lowered position (Position  1 ) wherein it is located beneath the surface of the ramp  22 A, to a generally horizontal medial position (Position  2 ) wherein it is generally planar with the surface of the ramp  22 A, to a raised position (Position  3 ) wherein it is oriented at a selected height above the surface of the ramp  22 A. In the different positions, the adjustable lip  24 A can be adjusted vertically to vary the elevation and angle of the flow of water  16  (supercritical flow) and enters the tailwater  48 A ( FIG. 2A ) where the flow transitions—via a hydraulic jump to subcritical flow. 
   In Position  3  ( FIG. 2A ) the downstream end of the adjustable lip  24 A can be located at a depth of from about 6 inches to 2 feet below the surface  30 A ( FIG. 2A ) of the flow of water  16 . This depth can be selected such that the water craft  19  ( FIG. 1 ) encounter a hydraulic formation  46  that is more retentive (i.e. a hole or A), so that craft are less likely to strike the adjustable lip  24 A. The lip  24 A can have a downward limit so as to reduce the chances of forming a hydraulic formation  46 B. The adjustable lip  24 A can also be oriented at an desired angle relative to the surface of the ramp  22 A or to the surface of the invert  26 A of the channel  14 - 1  ( FIG. 1A ),  14 - 2  ( FIG. 1B ). For example, the adjustable lip  24 A can be located at an angle of from 130 degrees to 230 degrees relative to the surface of the ramp, or at an angle of from 45 degrees (upward) to 45 degrees (downward) relative the invert  26 A of the channel  14 - 1  ( FIG. 1A ),  14 - 2  ( FIG. 1B ). 
   The base  28 A ( FIG. 2A ) for the adjustable lip  24 A can be formed of a solid material such as concrete, grouted concrete or steel anchored to the invert  26 A ( FIG. 2A ) of the channel  14 - 1  ( FIG. 1A ),  14 - 2  ( FIG. 1B ). In addition, the base  28 A can include a invert portion  31 A, a vertical portion  33 A and a shaped portion  35 A configured as a support for the placement mechanism  36 A. The adjustable physical structure  12 A ( FIG. 2-2A ) can also include adjustable wing wall structures  12 C, or adjustable wing wall block structures  12 E, configured to control the formation of the hydraulic formation  12 A and resist the tailwater  48 A from collapsing into the lower water surface  30 A above the horizontal member  40 A As will be further explained, the adjustable wing walls  32 A can be formed of interlocking blocks  34 A. 
   The adjustable lip physical structure  12 A ( FIGS. 2-2A ) can also include an adjustable placement mechanism  36 A configured to pivot or otherwise move the adjustable lip  24 A to the selected position (e.g., Positions  1 - 3 ). As shown in  FIG. 2A , the placement mechanism  36 A can comprise an inflatable bladder, which can be inflated or deflated as required to place the adjustable lip  24 A at the selected position. U.S. Pat. No. 7,114,879 to Obermeyer describes this type of inflatable bladder. With the placement mechanism  36 A formed as an adjustable bladder, the adjustable lip  24 A is preferably weighted to resist the hydraulic forces which tend to force the adjustable lip up and out of the flow of water  16 A. Alternately, the placement mechanism  36 A can comprise a hydraulic cylinder or an adjustable mechanism such as a mechanical jack. In this case the hydraulic cylinder or adjustable mechanism helps to lock the adjustable lip  24 A in the selected position (e.g., Positions  1 - 3 ). The adjustable lip physical structure  12 A ( FIG. 2-2A ) can also include a grate  56 A configured to prevent debris, whitewater recreationalist  11 , and water crafts  19  from getting under the adjustable physical structure or affecting the operation of the adjustable lip  24 A. 
   During operation of the adjustable lip physical structure  12 A ( FIGS. 2-2A ), the adjustable lip  24 A can be placed in the selected position (e.g., Positions  1 - 3 ) to form a desired hydraulic formation  46 A ( FIG. 2A ) in the tailwater  48 A ( FIG. 2A ) downstream of the adjustable lip physical structure  12 A. For example, depending on the position of the adjustable lip  24 A, the hydraulic formation  46 A ( FIG. 2A ) can comprise a wave or hole of a selected height and shape. For example, the hydraulic formation  46 A can comprise an A-jump which is characterized by the jump breaking at or upstream of the abrupt drop, (hole or retentive wave) (2) the wave jump or W-jump or the wave train which are characterized by the presents of waves, and (3) the B-jump which is characterized by a plunging jet (hole, or downstream formed wave). 
   Referring to  FIGS. 2B-2E  and  FIGS. 2F-2I , optional wave shaper extensions  50 A- 50 D for the adjustable lip physical structure  12 A are illustrated. The wave shaper extensions  50 A- 50 D are configured to vary the shape and character of the hydraulic formations  46 A ( FIG. 2A ). In each embodiment the wave shaper extension  50 A- 50 D bolts or otherwise attaches to the vertical member  38 A of the adjustable lip  24 A. The surface can be in the same plain as the surface of the horizontal element  40 A ( FIG. 2A ) of the adjustable lip  24 A or can be angled upward from 0 degrees to 30 degrees or downward from 0 degrees to 60 degrees. 
   In  FIG. 2B , a wave shaper extension  50 A has the shape a bell or a hillock with a selected height Ha and a selected width Wa. A representative value for Ha  24  can be from 0.5 feet to 6 feet. A representative value for Wa can be from be from 120 percent to 20 percent of the width of the horizontal element  40 A ( FIG. 2A ) of the adjustable lip In  FIG. 2B , a wave shaper extension  50 B has the shape of a paddle with a selected height Hb and a selected width Wb. Representative values for Hb and Wb are the same described for wave shaper extension  50 A. In  FIG. 2C , a wave shaper extension  50 C has the shape of a paddle with a selected height Hc and a selected width Wc. Representative values for Hb and Wb are the same described for wave shaper extension  50 A. In  FIG. 2D , a wave shaper extension  50 D has the shape of a paddle with a selected height Hd and a selected width Wd. Representative values for Hb and Wb are the same described for wave shaper extension  50 A. Wave shaper extension  50 B is shown oriented with a downward slope in  FIG. 2G , but all wave shaper extensions can be sloped upward or downward. The slope of the wave shaper extension can be adjusted with a placement mechanism  37 B to adjust the slope as required. In each embodiment the wave shaper extension  50 A- 50 D can be formed of a durable material such as metal or plastic. In addition, the surface of the wafer shaper extension  50 A- 50 D can be perforated, textured or otherwise shaped to further control the resultant hydraulic formation  46 A- 46 D. 
   Referring to  FIGS. 2J and 2K , an adjustable lip block physical structure  12 D is illustrated. The adjustable lip block physical structure  12 D performs the objectives similar to the adjustable lip physical structure  12 A ( FIG. 2A ) but without the adjustable lip  24 A ( FIG. 2A ). The adjustable lip block physical structure  12 D includes a crest  20 D and a ramp  22 D substantially similar to the previously described crest  20  ( FIG. 2A ) and ramp  22  ( FIG. 2A ). In addition, the ramp  22 A can also have a shape which converges the flow of water  16  towards the adjustable lip  24 A such that a more focused v-shaped hydraulic formation is produced (shown in  FIG. 2J ). The ramp  22 A can also have a shape which diverges the flow of water  16  towards the adjustable lip  24 A such that a broader hydraulic formation is produced. The adjustable lip block physical structure  12 D also includes a base  28 D formed of concrete or other suitable material, and an L-shaped lip block  66 D mounted or “keyed” to the base  28 D. The lip block shown  66 D forms a vertical lip  68 D adjacent to the invert  26 D of the channel  14 - 1  ( FIG. 1A ),  14 - 2  ( FIG. 1B ) which functions substantially similarly to the previously described adjustable lip  24 A ( FIG. 2A ) to form a desired hydraulic formation  46 D. Various configuration and sizes of lip blocks can be placed into the base  28 D to form different hydraulic formations  46 D. Alternate shapes of lip blocks  66 D includes downward and upward sloping adjustable lip which can slope from 45 degrees downward to 45 degrees upward. Lip blocks can also have a vertical lip  68 D that is higher or lower than the base  28 D. Different lip blocks  66 D can also be used in the same base  28 D to form various hydraulic formations  46 D. 
   Referring to  FIGS. 3 ,  3 A,  3 B,  3 C,  3 D and  3 E, an adjustable through-flow physical structure  12 B is illustrated. As shown in  FIGS. 3A and 3B , the adjustable through-flow physical structure  12 B is located on a stepped invert  26 B of the channel  14 - 1  ( FIG. 1A ),  14 - 2  ( FIG. 1B ) having a vertical drop  52 B. The adjustable through-flow physical structure  12 B includes a crest  20 B and a ramp  22 B which function substantially as previously described. The adjustable through-flow physical structure  12 B also includes a base  28 B, and a through-flow adjustable lip  24 B. The base  28 B can be formed of concrete or other building material placed along the vertical drop  52 B on the invert of the channel  26 B. The adjustable through-flow physical structure  12 B increases the effective flow in the hydraulic formation  12  B and decreases the Froude Number of the flow  16  as it passes over the shaped vanes  58  B or perforations. The adjustable through-flow structure is shown and described as a lip  24 B, however it can also be configured into the ramp  22 B. For instance it could be readily included into the ramp  22 F or  86 G as described below. 
   As shown in  FIGS. 3A and 3B , the adjustable through-flow physical structure  12 B also includes a plurality of adjustable placement mechanisms  36 B attached to the base  28 B configured to place the adjustable through-flow lip  24 B in a desired position in the flow of water  16 . In  FIGS. 3A and 3B , the adjustable through-flow physical structure  12 B is shown in two different positions. In  FIG. 3A , the adjustable through-flow lip  24 B is in a “raised” position located in the flow of water  16  above the lowest point of ramp  22 B. In  FIG. 3B , the adjustable through-flow lip  24 B is in a “lowered position” located in the flow of water  16  above the lowest point of the ramp  22 B. However, the illustrated positions (“raised” and “lowered”) are merely exemplary, as the adjustable through-flow lip  24 B can be placed in any desired position in the flow of water  16 . By way of example, the adjustable through-flow lip  24 B can be placed from the tailwater surface to 5 feet below the tailwater surface  48 B, at an angle of from 30 degrees upward to 45 degrees downward relative to the invert  26 B of the channel  14 - 1  ( FIG. 1A ),  14 - 2  ( FIG. 1B ) or tailwater surface  48 B. 
   As shown in  FIGS. 3A and 3B , the adjustable through-flow physical structure  12 B can also include a linkage plate  54 B which is pivotably attached to the base  28 B and to the adjustable through-flow lip  24 B. The linkage plate  54 B serves as an attachment member for attaching the adjustable through-flow lip  24 B to the base  28 B. If included, the linkage plate  54 B allows adjustment of the vertical elevation of the flow of water  16  as it enters the downstream pool  88 B. The adjustable through-flow physical structure  12 B also includes a grate  56 B attached to the adjustable through-flow lip  24 B and slidably supported by the invert  26 B of the channel  14 - 1  ( FIG. 1A ),  14 - 2  ( FIG. 1B ). The grate  56 B prevents debris from accumulating in the water proximate to the adjustable through-flow physical structure  12 B and can prevent whitewater recreationalists  11 , and water crafts  19  from getting under or into the adjustable flow-through physical structure  12 B or affecting the operation of the adjustable flow-through lip  24 B. 
   As also shown in  FIGS. 3A ,  3 B and  3 C, the adjustable through-flow lip  24 B can include a plurality of shaped vanes  58 B configured to direct water and allow water to flow freely as indicated by flow arrows  18 B through the adjustable through-flow lip  24 B. In addition, the shaped vanes  58 B ( FIG. 3B ) can have a curved shaped similar to turbine blades, which function to further shape the hydraulic formations  46 B ( FIGS. 3A and 3B ) in the tailwater  48 B ( FIGS. 3A and 3B ) downstream of the adjustable lip physical structure  12 A. For example, depending on the position of the adjustable through-flow lip  24 B, the hydraulic formation  46 B ( FIGS. 3A and 3B ) can comprise a wave substantially as previously described. Alternately, in place of shaped vanes  58 B, the through-flow adjustable lip  24 B can include holes, perforations, channels, slats, flat vanes, or other members that direct and allow water to flow freely through the adjustable flow-through lip  24 B. 
   The placement mechanisms  36 B ( FIGS. 3A and 3B ) can comprise adjustable mechanisms such as jacks or hydraulic cylinders which are pivotably attached to the base  28 B and to the through-flow adjustable lip  24 B. The placement mechanism can also be an inflatable bladder as shown in  FIG. 2A . As shown in  FIGS. 3A and 3B , the placement mechanisms  36 B, in combination with the adjustable through-flow lip  24 B and the linkage plate  54 B, form a four bar linkage that allows the adjustable through-flow lip  24 B to be placed in any desired position, and with any desired orientation relative to the flow of water  18  in the channel  14 - 1  ( FIG. 1A ),  14 - 2  ( FIG. 1B ). 
     FIG. 3D  illustrates adjustable wing wall physical structures  12 C in combination with the adjustable through-flow physical structure  12 B. The structure and function of the adjustable wing wall physical structures  12 C will be more fully explained in the paragraphs to follow.  FIG. 3E  illustrates three adjustable through-flow physical structure  12 B placed in series across the channel  14 - 1  ( FIG. 1A ) or  14 - 2  ( FIG. 1B ). 
   Referring to  FIGS. 4 ,  4 A and  4 B, an adjustable wing wall physical structure  12 C is illustrated. The adjustable wing wall physical structure  12 C is configured to control the formation of the hydraulic formation  46 C and resist the tailwater  48 C from collapsing into the lower water surface  30  above the lip  24 A, 24 B, 24 D, 24 F. For example, the adjustable wing wall physical structure  12 C can be located adjacent to, or in close proximity to, the adjustable through-flow physical structure  12 B ( FIG. 3D ), or any other adjustable physical structure herein described. The adjustable wing wall physical structure  12 C includes a base  28 C made of concrete or other suitable material. The base  28 C ( FIG. 4B ) can include a crest  20 C ( FIG. 4B ) and a ramp  22 C ( FIG. 4B ) constructed substantially as previously described. The base  28 C ( FIG. 4B ) can also include a vertical drop  70 C ( FIG. 4B ) downstream of the adjustable wing wall physical structure  12 C. The adjustable wing wall physical structure  12 C also includes a hinge plate  60 C attached to an upstream end of the stepped base  28 C, and a face plate  62 C attached to the hinge plate  60 C. The hinge plate  60 C allows the steel, ridged, inflated, or pliable face place  62 C to be pivoted or rotated into or out of the flow of water  16 . The face plate  62 C can also be made so as to allow vertical adjustment to further control the formation of the hydraulic formation  46 C and resist the tailwater  48 C from collapsing into the lower water surface  30 C above the adjustable lip physical structure  12 A or adjustable lip block physical structure  12 D. 
   The adjustable wing wall physical structure  12 C ( FIGS. 4 ,  4 A and  4 B) also includes a locking mechanism  64 C for the steel face plate  62 C attached to the stepped base  28 C. In  FIGS. 4 ,  4 A and  4 B, the steel face plate  62 C is shown in a locked or “closed” position. In the “closed” position, the steel face plate  62 C forms a sidewall of the channel  14 - 1  ( FIG. 1A ) or  14 - 2  ( FIG. 1B ), such that the flow of water  16  in the channel  14 - 1  or  14 - 2  is constrained by the steel face plate  62 C. Alternately, the steel face plate  62 C can be pivoted upward about the hinge plate  60 C out of the flow of water  16  to an “open” position. In the “open” position, the flow of water  16  is constrained by the base  28 C, such that the width of the channel  14 - 1  ( FIG. 1A ),  14 - 2  ( FIG. 1B ) has been effectively increased. In the “closed” position the flow of water is constrained by the steel face plate  62 C such that the width of the channel  14 - 1  ( FIG. 1A ),  14 - 2  ( FIG. 1B ) has been effectively decreased. The dimensions and the geometry of the steel face plate  62 C can be varied as required for different applications. 
   Referring to  FIGS. 5 ,  5 A and  5 B, an adjustable block wing wall physical structure  12 E is illustrated. The adjustable block wing wall physical structure  12 E is configured to adjust the width of the channel  14 - 1  ( FIG. 1A ),  14 - 2  ( FIG. 1B ). The adjustable block wing wall physical structure  12 E can be located adjacent to, or in close proximity to, the adjustable lip physical structure  12 A ( FIG. 2A ), or any other adjustable physical structure herein described. It can be configured to control the hydraulic formation  46 D and resist the tailwater  48 D from collapsing into the lower water surface  30 D above the adjustable lip physical structure  12 A or the adjustable lip block physical structure  12  E. 
   The adjustable block wing wall physical structure  12 E includes a base  28 E made of concrete or other suitable material. The base  28 E ( FIG. 5B ) can include a crest  20 E ( FIG. 5B ) and a ramp  22 E ( FIG. 5B ) constructed substantially as previously described. The base  28 E ( FIG. 5B ) can also include a vertical drop  70 E ( FIG. 5B ) downstream of the adjustable block wing wall physical structure  12 E. The adjustable block wing wall physical structure  12 E is constructed of individual lip blocks  34 E that are shaped with mating keys/grooves  72 E ( FIG. 5A ) such that the lip blocks  34 E can be stacked vertically. This allows the height of the adjustable block wing wall physical structure  12 E to be adjusted as required. 
   Referring to  FIGS. 6 ,  6 A and  6 B, an adjustable crest physical structure  12 F is illustrated. The adjustable crest physical structure  12 F includes an adjustable crest  20 F ( FIG. 6A ) configured to adjust the amount of hydraulic drop across the adjustable crest physical structure  12 F. The hydraulic drop is the difference in elevation between the water surface upstream and the water surface downstream of the adjustable crest physical structure  12 F. The adjustable crest  20 F ( FIG. 6A ) functions substantially similar to the previously described static crest  20 A ( FIG. 2A ) of the adjustable lip physical structure  12 A ( FIG. 2A ). The adjustable crest physical structure  12 F also includes an adjustable ramp  22 F ( FIG. 6A ), which functions substantially similar to the previously described static ramp  22 A ( FIG. 2A ) of the adjustable lip physical structure  12 A ( FIG. 2A ). The adjustable crest physical structure  12 F ( FIG. 6A ) also includes an adjustable lip  24 F, which functions substantially similar to the previously described adjustable lip  24 A ( FIG. 2A ) of the adjustable lip physical structure  12 A ( FIG. 2A ). 
   As shown in  FIG. 6A , the adjustable crest physical structure  12 F includes a base  28 F formed of a suitable building material such as concrete. The adjustable crest  20 F is hingedly mounted to the base  28 F on one or more hinge connections  74 F ( FIG. 6A ). The adjustable crest  20 F is movable from Position  1 , termed the “up” position, to Position  2 , termed the “down” position. In the “down” position the adjustable crest physical structure  12 F can have one-half foot or less of hydraulic drop. In the “up” position the adjustable crest physical structure  12 F can have as much as eight feet or more of hydraulic drop. The adjustable ramp  22 F is hingedly mounted to the adjustable crest  20 F on one or more hinge connections  76 F ( FIG. 6A ). 
   As also shown in  FIG. 6A , the adjustable crest physical structure  12 F includes a placement mechanism  36 F such as a bladder, hydraulic cylinder or mechanism substantially as previously described. The placement mechanism  36 F moves the adjustable crest  20 F to the different positions. The adjustable crest physical structure  12 F also includes a fixed or variable track slide mount  78 F ( FIG. 6A ) attached to the end of the adjustable ramp  22 F. With this arrangement, movement of the adjustable ramp  22 F in the vertical direction also moves the adjustable ramp  22 F in the horizontal direction. The track slide mount  78 F ( FIG. 6A ) can be adjusted so that the end of the adjustable ramp  22 F can be lower or higher with the adjustable crest physical structure  12 F in the “up” position then in the “down” position. The adjustable lip  24 F ( FIG. 6A ) can be fixedly attached to the adjustable ramp  22 F or can be pivotably attached and operated by a second bladder, hydraulic cylinder or mechanism (not shown). The adjustable crest physical structure  12 F can be operated in substantially the same manner as the adjustable lip physical structure  12 A for producing various hydraulic formations  46 F ( FIG. 6A ). 
   Referring to  FIGS. 7 ,  7 A and  7 B, an adjustable outlet physical structure  12 G is illustrated. The adjustable outlet physical structure  12 G connects to the outlets  80 G of one or more conveyance structures  82 G such as conduits or channels hence the term “adjustable outlet”. The conveyance structures  82 G are connected to a source of water  84 G ( FIG. 7B ), such as a pump, a channel, or a pipe configured to supply a flow of water  16 G ( FIG. 7B ) at a suitable flow rate and velocity. By way of example, the flow of water  16 G can be from 30 cfs (cubic feet per second) to 2000 cfs (cubic feet per second) or more and at a Froude Number from 1.2 to 4. 
   The adjustable outlet physical structure  12 G ( FIG. 7B ) includes a crest  20 G ( FIG. 7B ) configured to provide a hydraulic drop across the outlet adjustable physical structure  12 G. The crest  20 G ( FIG. 7B ) functions substantially similar to the previously described crest  20 A ( FIG. 2A ) of the adjustable lip physical structure  12 A ( FIG. 2A ). The crest  20 G ( FIG. 7B ) is preferably formed at an elevation above the downstream water surface elevation to prevent backflow or reverse flow from downstream pools when there is no flow of water  16 G ( FIG. 7B ) in the conduits  82 G ( FIG. 7B ). 
   The adjustable outlet physical structure  12 G ( FIG. 7B ) also includes a ramp  22 G ( FIG. 7B ), which functions substantially similar to the previously described ramp  22 A ( FIG. 2A ) of the adjustable lip physical structure  12 A ( FIG. 2A ). The adjustable outlet physical structure  12 G ( FIG. 7B ) can also include an adjustable ramp  86 G ( FIG. 7B ), which functions substantially similar to the previously described adjustable ramp  22 F ( FIG. 6A ). The adjustable outlet physical structure  12 G ( FIG. 7B ) can also include an adjustable lip  24 G, which functions substantially similar to the previously described adjustable lip  24 A ( FIG. 2A ) of the adjustable lip physical structure  12 A ( FIG. 2A ). 
   As shown in  FIG. 7B , the adjustable outlet physical structure  12 G includes a base  28 G formed of a suitable building material, such as concrete. The adjustable ramp  22 G is hingedly mounted to the base  28 G on one or more hinge connections  74 G ( FIG. 7B ). The adjustable ramp  22 G is movable from Position  1 , termed the “down” position, to Position  2 , termed the “up” position, or to any desired position in between Positions  1  and Position  2 . The ramp can be moved in this manner to account for variations in tailwater  48 G elevation or changes in flow  16 G rates. 
   As also shown in  FIG. 7B , the outlet adjustable physical structure  12 G includes one or more first placement mechanisms  36 G- 1  for moving the adjustable ramp  86 G, and a second placement mechanism  36 G- 2  for moving the adjustable lip  24 G. As previously described, the placement mechanisms  36 G- 1 ,  36 G- 2  can comprise bladders, hydraulic cylinders or jack mechanisms. In the illustrated embodiment, the first placement mechanisms  36 G- 1  comprise mechanical jacks, and the second placement mechanism  36 G- 2  comprises a bladder. The adjustable outlet physical structure  12 G takes advantage of energy (in the form of velocity head) that would otherwise be “wasted” to produce a useable hydraulic formation  46 G, such as a wave or a hole having side eddies. 
   With the source of water  84 G ( FIG. 7B ) for the adjustable outlet physical structure  12 G ( FIG. 7B ) being in the form of a pump, the adjustable outlet physical structure  12 G ( FIG. 7B ) can be placed in a still pool, such as a lake, swimming pool or tank, or in a river or channel. The adjustable outlet physical structure  12 G ( FIG. 7B ) can also be portable, as the source of water  84 G (e.g., pump), the conduit  82 G ( FIG. 7B ), the adjustable ramp  86 G ( FIG. 7B ), and the adjustable lip  24 G ( FIG. 7B ) can be easily transported and reassembled. 
   The source of water  84 G ( FIG. 7B ) can comprise a conventional propeller or mixed-flow impellor pump. Alternately, the source of water  84 G ( FIG. 7B ) can comprise a paddle wheel pump. One advantage of a paddle wheel pump is energy losses are reduced and efficiency is increased due to the desired nature of the pumped outflow. Specifically, the outflow of a paddle wheel pump has a low lift (less than 4 feet) and a high velocity (approximately 8 to 20 feet per second). The outflow of the paddle wheel pump can also be distributed across the width (cross section) of the adjustable outlet physical structure  12 G ( FIG. 7B ). This output width can thus be achieved without the need to contract, and then expand the flow as is necessary with a conventional pump. 
   With the source of water  84 G ( FIG. 7B ) in the form of either a pump or a paddle wheel, power can be supplied by an electric or gas engine or a water powered turbine. The return flow of the source of water  84 G can be through the bottom and/or through the side of the outlet adjustable physical structure  12 G ( FIG. 7B ). Flow routed through the bottom (below the adjustable lip  24 G) enhances the formation of the hydraulic formation  46 G ( FIG. 7B ), and decreases velocities at the downstream end of the downstream pool  88 G ( FIG. 7B ). Flow routed through the side of the adjustable outlet physical structure  12 G ( FIG. 7B ) can be used to decrease the intensity of the eddy if focused near the eddy line (i.e., the boundary between the eddy and the supercritical flow). In addition, the flow and formation of the hydraulic formation  46 G ( FIG. 7B ) can be adjusted with the pumping rate. 
   Referring to  FIGS. 8 ,  8 A and  8 B, an expandable invert physical structure  12 H is illustrated. The expandable invert physical structure  12 H ( FIG. 8B ) comprises a reinforced rubber membrane that is inflated with either air or water. Exemplary reinforcing materials include nylon, polypropylene, Kevlar, steel, and other reinforcing fibers. The expandable invert physical structure  12 H ( FIG. 8B ) can expand and rise according to a predetermined shape as controlled by the internal reinforcing. For typical applications, the expandable invert physical structure  12 H ( FIG. 8B ) can range from 2 feet to 25 feet in length and from 6 feet to 25 feet in width. 
   The expandable invert physical structure  12 H can be used to form a hydraulic drop for any of the previously described adjustable physical structures  12 A- 12 G. The height of the expandable invert physical structure  12 H ( FIG. 8B ) can be selected on the basis of the desired hydraulic drop with from 2 feet to 10 feet being representative. For example, as shown in  FIG. 8B , the expandable invert physical structure  12 H can be placed on the invert  26 B of the channel  14 - 1  or  14 - 2  upstream of the adjustable through-flow physical structure  12 B in place of the crest  20 B ( FIG. 3A ) and ramp  22 B ( FIG. 3A ) to form hydraulic formations  46 B. As another example, the expandable invert physical structure  12 H can be used with the adjustable outlet physical structure  12 G ( FIG. 7B ) in place of the adjustable ramp  86 G ( FIG. 7B ). 
   Referring to  FIGS. 9 and 9A , a moveable invert physical structure  12 I is illustrated. The moveable invert physical structure  12 I is configured for placement on the invert  261  of the channel  14 - 1  ( FIG. 1A ) or  14 - 2  ( FIG. 1B ). Because of it&#39;s size the moveable invert physical structure  12 I can be easily moved and placed at a desired location on the system  10 - 1  ( FIG. 1A ) or  10 - 2  ( FIG. 1B ). The moveable invert physical structure  12 I comprises a reinforced rubber membrane that is inflated with either air or water. As shown in  FIG. 9A , the moveable invert physical structure  12 I can expand and rise according to a predetermined shape as controlled by the internal reinforcing. In addition, multiple moveable invert physical structure  12 I can be placed in series and adjusted to create optimal hydraulic formations such as waves, holes and eddies. Further, the spacing between the moveable invert physical structure  12 I can be adjusted to take advantage of the natural wavelength and to enhance the size and the formation of a wave train. 
   As shown in  FIG. 9 , individual moveable invert physical structure  12 I can be made as a single element or divided into individual segments. In  FIG. 9A , the cross sectional geometry of the moveable invert physical structure  12 I is semi-circular comprising between ⅛ to ½ of the circumference of a full circle. The diameter of the circular cross section is typically between 2 to 10 feet. Other curve-linear and triangular cross sections can provide similar results, but the semicircular section is the easiest and least expensive to make. 
   EXAMPLES 
   The described adjustable physical structures  12 A- 12 I have undergone extensive experimentation and testing. Experimentation included hydraulic Froude scale modeling at 1:12 scale in Woodstock Md. Over 20 configurations were tested and four configurations were selected for further testing and development. 
   Hydraulic Froude scale modeling at a 1:12 scale, was conducted at a hydraulics laboratory at Colorado State University in Fort Collins Colo. 
   Testing and observation of six full scale prototypes built in McHenry, Md. was also conducted by the inventor. Survey data was taken and wave formations were documented. A second series of testing and observations was also conducted by the inventor. This testing included collecting formalized input from over 60 tip athletes and testing by the inventor. 
   While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and subcombinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope.