US20150104988A1 - Watercraft Fin - Google Patents

Watercraft Fin Download PDF

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Publication number
US20150104988A1
US20150104988A1 US14/403,984 US201314403984A US2015104988A1 US 20150104988 A1 US20150104988 A1 US 20150104988A1 US 201314403984 A US201314403984 A US 201314403984A US 2015104988 A1 US2015104988 A1 US 2015104988A1
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Prior art keywords
fin
dimples
flow
foil
diameter
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US14/403,984
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English (en)
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Courtney James Potter
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SIDEWAYS SPORTS Ltd
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SIDEWAYS SPORTS Ltd
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Priority claimed from AU2012902195A external-priority patent/AU2012902195A0/en
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Assigned to SIDEWAYS SPORTS LIMITED reassignment SIDEWAYS SPORTS LIMITED ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: POTTER, Courtney James
Publication of US20150104988A1 publication Critical patent/US20150104988A1/en
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    • B63B35/7926—
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B32/00—Water sports boards; Accessories therefor
    • B63B32/60—Board appendages, e.g. fins, hydrofoils or centre boards

Definitions

  • the present invention relates to a fin for a watercraft and in particular a fin for a surfboard.
  • the fin can act as a stabilizer which allows the user or rider greater control and enjoyment over the board or watercraft.
  • Modern surfboards most commonly use the 3 and 4 fin arrangement. These 3 and 4 fin designs known as the “Thruster” and “Quads” are able to maintain hold of the wave face and create propulsion. The propulsion is generated from the outward forces created by the side fins during turning.
  • the Side fins (left and right) work on similar principles to an aircraft wing. Fluid as it travels over the fin, moves faster over the curved foil face than it does on the flat inside foil face of the fin. This results in a high pressure on the flat side and a low pressure on the curved side. The high pressure is pushing the foil upwards. This creates lift for an airplane wing, or in the case of a surfboard fin, the high pressure is pushing the foil/fin outwards.
  • the lift created outwards on the fin is the sensation surfers “feel” when turning known as “drive.” The feel is based on the amount of control, speed, and maneuverability a fin can produce. Drive is activated as the surfboard is turning and the angle of attack (flow) across the fin is such that it creates lift. If this outward force (lift) can be increased then this increases the amount of drive a fin has.
  • the design of the fin has been important, the actual construction of the fin is also critical. For example, it is understood that to minimize drag it is important to ensure that the surface of the fin is as smooth as possible so as to reduce the friction between the fin and water. It has been understood that friction needs to be reduced as much as possible to ensure that the fin is able to smoothly glide through the water.
  • a fin for a surfboard or other watercraft wherein the surface of the fin includes a plurality of dimples which improve the performance of the fin.
  • a dimple is like a small depression or indentation on the surface.
  • the present invention provides a watercraft fin including a first side surface and a second side surface wherein at least one of the first side surface or the second side surface includes a plurality of dimples.
  • Reference to the two sides will be understood as referring to the two main faces of a fin. In conventional fins, for a side fin one side would be substantially flat and the other side would be curved. These sides can be compared to the top and bottom of an aircraft wing.
  • the dimples will be substantially circular and have a diameter of between 2.0 mm and 4.5 mm, and a depth between 0.1 mm and 0.5 mm. Ideally, the diameter will be between 3.8 mm and 4.3 mm, and the depth between 0.2 mm and 0.5 mm.
  • the spacing of the dimples is also important to the invention. It is expected that the midpoints between adjacent dimples will be between 3.7 mm and 4.5 mm apart, wherein the midpoint is considered the center of the dimple and adjacent dimples refers to two dimples that are located proximate to each other and without any other dimples being located in between.
  • edges of adjacent dimples may be located between 0.2 mm and 0.5 mm apart. In preferred arrangements the distance between adjacent edges is between 0.3 mm and 0.4 mm.
  • the dimples may also be arranged in lines. In some embodiments these lines will be substantially parallel to the base of the fin, or plane of the watercraft.
  • the base of the fin is that part of the fin that joins with or attaches to the watercraft, whereas the opposite end is the tip of the fin. In alternative embodiments these lines will run between 170 degrees and 190 degrees relative to the base of the fin that is +/ ⁇ 10 degrees from parallel.
  • substantially the whole side of the fin will be dimpled.
  • the dimples will be located from the widest point of the fin to the rear edge of the fin.
  • the dimples may also be located on both sides of the fin, or limited to one side only, depending on the performance required.
  • the dimples may be hexagonal, triangular, rectangular, oval or square in shape. Further, some arrangements may elect to have varying dimple sizes, or the dimples increasing in size in a line starting from the leading edge of the fin extending to the trailing edge of the fin.
  • the present invention is a marked departure from conventional thinking employed in the design of current fins.
  • the inclusion of dimples has led to marked improvements in the performance of fins, and thereby the watercraft to which they are attached.
  • FIG. 1 a exemplifies the flow of water about a smooth surface.
  • FIG. 1 b exemplifies the flow of water about a dimpled surface.
  • FIG. 2 a demonstrates flow of water over the surface of a smooth foil.
  • FIG. 2 b demonstrates flow of water over the surface of a dimpled foil.
  • FIG. 3 a demonstrates the creation of vortices about the tip of a fin.
  • FIG. 3 b demonstrates the reduction of tip vortices through the use of dimples.
  • FIGS. 4 a - 4 c show the preferred location of dimples for different arrangements.
  • FIG. 5 shows a foil of one embodiment of the present invention.
  • FIG. 6 shows a representational cross sectional view of the foil of FIG. 5 (i.e. the dimples are not to scale).
  • FIG. 7 shows a foil of an alternative embodiment of the present invention.
  • FIG. 8 shows possible shape variations for the dimples.
  • FIG. 9 shows possible dimple arrangements on the curved outer face of a fin.
  • FIG. 10 shows possible dimple arrangements on the “flat” inner face of a fin.
  • FIGS. 11 a - 11 c show possible foil shapes.
  • FIG. 12 shows a foil of an alternative embodiment of the present invention.
  • FIG. 13 shows a foil of an alternative embodiment of the present invention.
  • FIG. 14 shows a foil of an alternative embodiment of the present invention.
  • FIG. 15 a - 15 c show possible dimple arrangements on the applicants prior fin designs.
  • FIG. 16 shows the arrangement of a preferred embodiment of the present invention.
  • FIG. 17 shows the preferred depth and arrangement of one embodiment of the present invention.
  • FIGS. 18 a - 18 d show alternative embodiments of the present invention.
  • FIG. 19 shows the number of dimples on the curved outer face of a small isometric fin in one embodiment of the present invention.
  • FIG. 20 shows the number of dimples per side of a small symmetrical fin in one embodiment of the present invention.
  • FIG. 21 shows the number of dimples on the curved outer face of a medium isometric fin in one embodiment of the present invention.
  • FIG. 22 shows the number of dimples per side of a medium symmetrical fin in one embodiment of the present invention.
  • FIG. 23 shows the number of dimples on the curved outer face of a large isometric fin in one embodiment of the present invention.
  • FIG. 24 shows the number of dimples per side of a large symmetrical fin in one embodiment of the present invention.
  • FIG. 25 illustrates the spacing of dimples from the edge of the fin in one embodiment of the present invention.
  • FIG. 26 shows an alternative measuring to that of FIG. 25 .
  • FIG. 27 shows preferred setbacks of dimples for a particular fin of one embodiment of the present invention.
  • FIG. 28 a shows simulated flow streamlines over a conventional fin.
  • FIG. 28 b shows simulated flow streamlines over a dimpled fin.
  • FIG. 29 is a graph and table comparing the lift force (N) of a dimpled fin to a conventional fin without dimples.
  • Laminar flow is also known as streamlined flow and is the flow of a fluid in parallel layers. The fluid will continue to flow in straight lines without mixing of the layers.
  • streamlined flow is the flow of a fluid in parallel layers.
  • the fluid will continue to flow in straight lines without mixing of the layers.
  • the parallel layers continue in the same general direction (left to right in the figure), however a large amount of separation between the layers is created.
  • the effect of the dimples is to reduce the separation.
  • the dimples on the surface create a turbulent flow, which draws the flow back over the foil/fin and prevents back-flow, also called flow separation, from the high pressure region in the back.
  • the turbulent boundary layer contains more energy, so it will delay separation until a greater magnitude of negative pressure gradient is reached, effectively moving the separation point further aft on the foil and possibly eliminating separation completely.
  • FIG. 2 a exemplifies water flow over the surface of a fin. Similar to the smooth object in FIG. 1 a , the smooth surface of the fin in FIG. 2 a does not provide any attraction, and allows a large separation between the water and the surface of the fin. As a result the flow shears off the foil creating cavitation which results in a stalling of the fin during maneuvers or high angles of attack.
  • FIG. 2 b demonstrates the effect of the dimples on the surface of the fin. In this case, turbulent flow created by the dimples draws the lamina flow back over the curved foil surface, allowing the foil to function at more extreme angles of attack.
  • FIG. 3 a shows the known problem of vortices being created about the tip of the fin.
  • These fin tip vortices are associated with induced drag, an unavoidable side-effect of the fin generating lift.
  • Fin tip vortices form the major component of wake turbulence.
  • a fin generates aerodynamic lift by creating a region of lower pressure in front of the fin as shown in FIG. 3 a . Fluids are forced to flow from high to low pressure and the fluid behind the fin tends to migrate toward the top of the fin via the fin tips. The fluid does not escape around the leading edge of the fin due to velocity, but it can flow around the tip. As a consequence, fluid flows from behind the fin and out around the tip to the front of the fin in a circular fashion. This leakage will raise the pressure in front of the fin and reduce the lift that the fin can generate.
  • tip vortices can be lessened through the use of dimples about the tip of the fin. This is demonstrated in FIG. 3 b .
  • the dimples reduce the leakage of flow over the tip. By creating a turbulent flow along the tip it draws the escaping flow back to the tip surface.
  • Boundary layers can be either laminar or turbulent.
  • Fins to date, have a smooth surface that results in a laminar flow of water over the fins. Achieving this laminar flow has been, and remains presently, the objective in the industry. However, in high angles of attack which a fin is subject to, the laminar flow actually increases drag and reduces the performance of a fin when contrasted with the present invention.
  • the introduction of the dimples on the fin in the present invention results in a turbulent flow of water over the surface of the fin.
  • the introduction of dimples on the fin reduces the separation of the water flowing over the fin by pulling the water molecules to the surface of the fin, thereby delaying energy sapping separation of the water flows. This is due to reducing the laminar separation of the flowing water over the surface of the fin.
  • Flow separation occurs when the boundary layer travels far enough against an adverse pressure gradient that the speed of the boundary layer relative to the fin falls almost to zero.
  • the fin becomes less efficient as the boundary layer separates resulting in less lift and speed and a stalling of the fin.
  • Boundary layer separation occurs when the portion of the boundary layer closest to the surface of the fin or leading edge reverses in flow direction. As a result, the overall boundary layer initially thickens suddenly and is then forced off the surface by the reversed flow at its bottom. The fluid flow becomes detached from the surface of the smooth surface fin, and instead takes the forms of eddies and vortices (as shown in FIG. 2 a ). In flow dynamics, flow separation results in increased drag.
  • the present invention creates a dimpled surface on a fin that thereby creates a turbulent flow of water over the fin surface.
  • the addition of dimples to the curved surface of the foil promotes the boundary layer to transition from laminar to turbulent sooner (compared to the standard design) along the foil's length.
  • the turbulent boundary layer is able to remain attached to the surface of the foil much longer than a laminar boundary layer, reducing the overall pressure drag.
  • a downside of this is the slightly increased viscous drag of a turbulent boundary layer compared to a laminar boundary layer.
  • testing of dimpled fins has shown reduced pressure on the curved side of the fin resulting in an increased lift (9-12%) for angle of attacks between 7.5-15 degrees.
  • the placement of the dimples can be influenced by the intended use, or desired effect of the fin.
  • FIGS. 4 a - 4 c there is shown the preferred location of dimples based on the expected angle of attack.
  • the angle of attack is the direction of the water flow when it comes into contact with the fin.
  • FIG. 4 a if the fin is traveling in a straight line then the inclusion of dimples behind the widest point of the cross-section of the foil can create a clean transition without a lamina separation bubble forming. This clean transition reduces the pressure drag caused by the foil and thus improves performance.
  • the transition is where the flow begins to change from lamina to turbulent. When the pressure changes from high to low, the flow detaches from the foil.
  • the boundary layer Between the fins surface and where the fluid is undisturbed.
  • the boundary layer will be laminar near the leading edge and will become turbulent a certain distance from the leading edge (depending on surface roughness and Reynolds Number (speed)).
  • speed Reynolds Number
  • the dimples are located on one side of the fin only, as shown in FIG. 4 b . Generally, this will be the lift generating side of the fin. However in other arrangements the dimples will be located on both sides of the fin as shown in FIG. 4 c . This will particularly be the case for asymmetrical fins.
  • the dimpled surface induces an early transition to a turbulent flow regime with the benefit of controlling the separation of the water from the surface.
  • dimples may be placed to a lesser or greater extent over the surface of the fin, or portions of the fin. Referring to FIG. 9 , various embodiments are shown with the dimpled section of the fin in each case shaded.
  • Surfing conditions also vary greatly and different dimple arrangements can be preferred in different conditions, i.e. more dimple coverage will result in a grippier feel and less feeling of the fins sliding out, this arrangement would be better in steeper waves and larger waves.
  • fins have an active curved side and a flat side.
  • a common exception is the single fin and center fin in a tri fin arrangement.
  • the center fin is usually symmetrical with both sides being curved.
  • FIG. 11 b shows a curved upper face and a flat inner face.
  • FIG. 11 a shows a curved upper face, and a slightly curved inner face which, for simplicity, we will consider flat like the foil of FIG. 11 b .
  • FIG. 11 c shows the symmetrical foil shape with both the upper and inner faces being curved. This is the foil which is commonly used as a center fin and single fin.
  • the primary dimple arrangements are placed on the curved face of the fin. These arrangements have been explained above and exemplified in FIG. 9 . However, benefit is also gained from inclusion of dimples on the “flat” side of the fin.
  • FIG. 10 shows the preferred location of dimples on the flat side of the fin. These are areas of expected separation.
  • the dimples will be circular in shape. Circular is preferred as, due to the combination of the wave and surfers' maneuvering, the flow is constantly changing and there is no steady flow from one direction.
  • the circular dimples are uniform in the way they deal with the various flow angles. In modern day surfing, the surfer may turn 360 degrees and ride the surfboard backwards. In these circumstances, the round circular dimples can give a uniform result no matter which direction the surfers is traveling.
  • a variety of different shapes can be used. Preferred shapes for the dimples are shown in FIG. 8 . The selection of dimple shape can depend on the intended use. Different performance may also be required for different craft.
  • a wake board is towed behind a boat and generally goes in a straighter line and is not subject to as wide angles of attack as a surfboard is. Therefore, the wakeboard can benefit from dimples that are not circular, such as, for example, hexagon shaped dimples, although it will be understood that circular dimples will still improve performance.
  • the dimples will be of a common size and shape. However, in some cases varying size dimples may be utilized. These variations of sized dimples could be smaller (0.1 mm depth ⁇ 2.0 mm width) at the tighter radius section of the leading edge, just forward of the widest point of the fin, leading to larger dimples in increments of about 1.0 mm until they reach a maximum size of size 0.325 mm depth ⁇ 4.0 mm width as they traverse the foils curved shape face, reducing in size to 0.1 mm depth ⁇ 2.0 mm width in increments of 1.0 mm as they approach the trailing edge.
  • the preferred dimples have a diameter between 2.0 mm and 4.5 mm and a depth between 0.1 mm and 0.5 mm. It has been found that if the diameter is too small, for example less than 2.0 mm, it increases drag without reducing the pressure drag or increasing the lift to counter the increase, and similarly if the diameter is too large, for example greater than 5 mm, then the surface area is increased too much and again drag is created.
  • the dimples have a diameter of between 2.0 mm and 4.5 mm with the optimum diameter being between 3.8 mm and 4.3 mm.
  • the depth of the dimples would also range from 0.2 mm to 0.5 mm, with an ideal range being between 0.28 mm and 0.325 mm.
  • the dimples would have a diameter of 4.036 mm and a depth of 0.325 mm.
  • the center of each dimple would be located 4.378 mm apart, providing a spacing of 0.367 mm between each dimple.
  • FIG. 18 shows varying diameters, depth, and spacing of other preferred embodiments of the present invention.
  • the dimples will be arranged such that the distance between each dimple edge is between 0.2 mm and 5 mm.
  • the ideal distance between the edges of each dimple is 0.3 mm to 0.4 mm.
  • the preferred range is between 3.70 mm and 4.5 mm.
  • the number of dimples per side of the fin is preferably between 350 to 900.
  • the range of dimples per side is dependant on the size of the fin. For example, small, medium, and large sized fins may have the following dimensions and dimples:
  • FIG. 19 to FIG. 24 also show the preferred number of dimples on each “line.”
  • each line of dimples will be substantially parallel to the surface of the surfboard or watercraft to which the fin is applied. This equates to each line of dimples being substantially parallel to the base of the fin which is then connected to the surfboard or watercraft.
  • the preferred arrangement will have the line of dimples being substantially parallel, or 180 degrees, other embodiments may have the dimples arranged at between 170 degrees and 190 degrees. That is, although the preferred angle of rows of dimples is parallel to the base of the fin, variations of up to 10 degrees are acceptable.
  • the fin with dimples may be provided.
  • substantially the entire outer surface of the fin is dimpled, although the dimples are set back from the edge.
  • the leading edge of the fin should be dimple free so as to maintain the curve of the foil, and thus not disturbing the Coanda Effect.
  • the trailing edge of the fin is dimple free so as to reduce vibration at the thinner section of the foil.
  • the dimples would be no closer than 5 mm to the trailing edge.
  • FIGS. 25 and 26 demonstrate the preferred set backs from the edge of the fin. From FIG. 25 it can be seen that the set back from the edge of the fin in a line parallel with the line of dimples is between 5.0 mm and 60.0 mm. Alternatively, as shown in FIG. 26 , the center of each dimple closest to the edge of the fin is located between 8.0 mm and 60.0 mm perpendicularly from the edge of the fin.
  • the preferred setback relative to dimensions of one embodiment of the present invention is also shown in FIG. 27 .
  • the fin has a dimpled surface located a set distance from the leading edge of the foil. This offset distance can be determined by reference to where the widest point of the foil is, and ensuring that the dimples begin behind this wide point. After the widest point of the foil is where the flow tends to separate. Dimples placed after the widest point will reduce the separation by creating a turbulent layer drawing the flow back.
  • the dimples are located on the fin in areas where computational flow dynamics determine the greatest flow separation (and cavitation) occurs.
  • the separation point in which the boundary layer breaks away from the surface of the fin due to the magnitude of the positive pressure gradient. Beneath the separated layer, bubbles of stagnant air form, creating additional drag because of the lower pressure in the wake behind the separation point.
  • the present invention improves the performance of watercraft fins, such as surfboard fins in modern surfing (which have dynamic maneuvers with high angles of attack) by introducing the dimpled surface to better control the surfboard.
  • the conventional fin design with a smooth flat surface is unable to maintain its hold on the wave in extreme directional changes due to the cavitation caused by the separation of the flow over the foil surface of the fin.
  • the dimple design utilizes turbulence to delay the flow separation, reducing cavitation and drag.
  • the turbulent boundary layer helps the flow overcome an adverse pressure gradient and remain attached to the surface longer than it would otherwise.
  • the size, depth, and distance apart of the dimples of the present invention are important and have a large effect on the overall performance of the fin and manufacture. If the dimples are too large in terms of depth and width, they create too much surface area resulting in an increase in the drag. Further, the lift is reduced and are therefore unable to offset the increased drag. Additionally with a larger, deeper dimple, the flex characteristics of the materials used to make the fin begin to change, making the material too thin in areas and also becoming too flexible or brittle thus reducing performance and making the fin difficult to manufacture. Conversely, dimples that are too small or shallow do not provide the increased performance but rather increase the drag of the fin. The distance between the dimples also affects the performance of the fin.
  • dimples too close together will again also affect the flex characteristics of the materials used to make the fin, making the material too thin in areas and becoming too flexible, thus reducing performance and making the fin difficult to manufacture.
  • dimples too far apart reduce the amount of lift created by the dimples and are therefore unable to offset the drag.
  • the present invention thus provides parameters for dimples that produce improved performance that is contrary to conventional thinking within the industry.
  • Injection molding is a manufacturing process for producing parts from both thermoplastic and thermosetting plastic materials. Material is fed into a heated barrel, mixed, and forced into a mould cavity where it cools and hardens to the configuration of the cavity.
  • Suitable materials may include: fiberglass, polyester, polycarbonate, polycarbonate with a glass fiber, nylon, nylon with a glass fiber, aluminum, epoxy, wood, rubber, and other thermoplastics.
  • the preferred materials that replicate the flex characteristics of fiberglass are nylon with 30-50% glass fiber, or alternatively nylon with 30-50% carbon fiber or KEVLAR®. It is not essential that the flex characteristics of fiberglass be maintained, however, existing surfers are comfortable with the feel of existing fiberglass fins and hence the preference to provide a similar flex characteristic.
  • nylon KEVLAR® is considered less abrasive on tooling but is a less commonly used material and more expensive.
  • HydlarTM from Ensinger Industries Inc. has been found to be a suitable material.
  • An alternative is Nylon 6TM from IG Maschinen.
  • Nylon filled with KEVLAR® aramid fibers results in a material that is both stronger and has a greater wear resistance to nylon alone.
  • Such a thermoplastic composite will generally outperform other reinforced plastics and, in particular, increase the tensile and flexural strengths.
  • FIG. 29 compares the lift force (N) of a dimpled fin of the present invention compared to a conventional fin without dimples.
  • the graph of FIG. 29 shows the resultant lift provided by the respective fins at various flow angles (angles of attack). This graph illustrates two key points. Firstly, the dimpled design of the present invention has significantly more lift between 7.5 and 15 degrees. The increase in lift at these points is important as it increases the drive allowing a surfer to push the board harder and gain more speed through turns.
  • the second point is that the conventional fin design is unable to reduce the dramatic stalling effect after 25 degrees is reached. While the dimpled fin still stalls beyond the 25 degree point, the stalling is not as dramatic as for a conventional fin, allowing the surfer to maintain the hold required to complete the turn.
  • FIGS. 28 a and 28 b show the simulated flow streamlines as they approach and go over the fin.
  • FIG. 28 a shows the flow over a standard, or conventional fin
  • FIG. 28 b shows the flow over the same fin design with the addition of dimples.
  • FIG. 28 a in particular, shows fin tip vortices. Fin tip vortices are circular patterns of rotating fluid left behind a fin as it generates lift.
  • FIGS. 28 a and 28 b again show two aspects of the present invention.
  • the tip of the standard fin has a spiraling turbulent flow in its wake. This is what is known as tip vortices. Tip vortices create drag, stalling, and reduced performance of the fin. The inclusion of dimples on the fin largely eliminate the tip vortices, resulting in reduced drag, less stalling, and an improved overall performance compared to the conventional fin.
  • the present invention has disclosed a dimpled surface area on the fin surprisingly increasing the lift generated by the fin and reducing the effects of pressure drag and tip vortices.
  • the dimpled fin of the present invention provides greater drive and maneuverability, while maintaining hold and grip in the water, which is usually sacrificed when using a smooth fin in critical maneuvers.
  • dimples Prior to the present application the addition of dimples would have been seen as introducing imperfections that increased the surface area, drag of a fin, and, thereby, a degraded performance.
  • the addition of dimples on the surface of the fin as described herein utilizes the turbulent flow created to maintain the connection of the water flow to the surface of the fin longer during extreme changes of direction when subject to high angles of attack. This maintains the speed and holding ability of the fin during the maneuvers, thereby increasing performance of the surfboard.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • Ocean & Marine Engineering (AREA)
  • Laminated Bodies (AREA)
  • Filling Or Discharging Of Gas Storage Vessels (AREA)
  • Details Of Rigid Or Semi-Rigid Containers (AREA)
  • Table Devices Or Equipment (AREA)
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US14/403,984 2012-05-28 2013-05-28 Watercraft Fin Abandoned US20150104988A1 (en)

Applications Claiming Priority (5)

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AU2012902195A AU2012902195A0 (en) 2012-05-28 Watercraft Fin
AU2012902195 2012-05-28
AU2012905498A AU2012905498A0 (en) 2012-12-14 Watercraft fin
AU2012905498 2012-12-14
PCT/AU2013/000548 WO2013177612A1 (en) 2012-05-28 2013-05-28 Watercraft fin

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EP (1) EP2855256A4 (enExample)
JP (1) JP2015517954A (enExample)
CN (1) CN204822021U (enExample)
BR (1) BR112014029748A2 (enExample)
CA (1) CA2874038A1 (enExample)
MX (1) MX2014014510A (enExample)
NZ (1) NZ703435A (enExample)
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US9637205B1 (en) 2015-12-28 2017-05-02 Jacob Saunooke Curved surfboard fin
CN107902073A (zh) * 2017-12-20 2018-04-13 北航（四川）西部国际创新港科技有限公司 无人机
US20180237112A1 (en) * 2015-08-18 2018-08-23 Jbooks Holdings Pty Ltd A fin for a surfboard
US10106230B2 (en) * 2015-06-02 2018-10-23 Randal Richenberg Biomimic design stabilizing fin or keel for surface planing or submerged watercraft

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JP6382603B2 (ja) * 2013-08-20 2018-08-29 株式会社東芝 水車
US9463588B2 (en) * 2014-02-07 2016-10-11 Todas Santos Surf, Inc. Surf fin including injection molded pre-impregnated composite fiber matrix inserts
WO2016083977A1 (pt) 2014-11-24 2016-06-02 Elenco De Qualidade Equipamentos De Controlo Unipessoal, Lda Casco para embarcação ou prancha, compreendendo recessos como elementos hidrodinâmicos
DE102015103021A1 (de) * 2015-03-03 2016-09-08 Ellergon Antriebstechnik Gesellschaft M.B.H. Hydrofoilfinne
CN104787259B (zh) * 2015-04-27 2016-11-16 东莞市诺峰实业有限公司 一种冲浪板鳍片及其制作工艺
IT201800003433A1 (it) * 2018-03-12 2019-09-12 Rovercraft Di F Russo Propulsore marino di tipo intubato dalle prestazioni aumentate

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CN204822021U (zh) 2015-12-02
EP2855256A4 (en) 2016-03-23
BR112014029748A2 (pt) 2017-06-27
JP2015517954A (ja) 2015-06-25
CA2874038A1 (en) 2013-12-05
NZ703435A (en) 2016-06-24

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