WATERCRAFT COMPONENTS THAT INCLUDE A FLUID SYSTEM

Abstract

Watercrafts that include a fluid system are described. An example watercraft includes a fluid system, a hull, a sail, and a compressor. The hull has a bow and a stern. The sail has a first end, a second end disposed on the hull, a lengthwise axis, a central axis, a first side, a second side, and defines an injection opening, a suction opening, and a channel. The lengthwise axis extends from the first end to the second end. The central axis is disposed orthogonally to the lengthwise axis and between the first side and the second side. The suction opening is disposed on the second side and between the injection opening and the first side. The channel extends from the suction opening to the injection opening such that fluid can travel into the suction opening and exit the injection opening. The compressor is disposed within the channel.

Description

FIELD

The disclosure relates generally to the field of fluid systems. More particularly, the disclosure relates to watercraft components that include a fluid system.

BACKGROUND

There are all types of watercrafts used to travel on water, such as motorboats, yachts, cargo ships, maritime ships, aircraft carriers, container vessels, and others. Watercrafts have traditionally made use of propellers within the water or sails to generate thrust, used rudders to control the directionality of the watercraft, and are generally impacted by large drag forces. However, current thrust generating features, rudders, and other components of watercrafts have drawbacks.

For example, there are generally strong winds over the ocean, which can be used to propel a watercraft using a sail. However, sails are rarely used as the primary form of propulsion in watercraft as fossil fuels engines are widely used (e.g., in cargo ships). As climate change becomes more relevant in determining what type of propulsion systems should be utilized, using wind for watercraft propulsion is an available method that can result in an overall CO₂ emission reduction relative to watercraft that use fossil fuel engines. In particular, 90% of the cargo in the world is transported by marine ships. Traditional soft sails are inefficient for these types of ships and require a large surface area to generate useful thrust.

Furthermore, current rudders and hydrofoils could be improved to reduce drag, increase control authority, and reduce overall energy consumption. For example, hydrofoils and hydrowings are mostly used for small and lightweight ships and rarely used for large ships, such as marine cargo ships and large navy ships (e.g., aircraft carriers), because these components need to be very large to generate a useful lift for drag reduction.

A need exists, therefore, for new and useful watercraft components and features to reduce drag, reduce energy consumption, increase performance, increase rudder control authority, and/or provide an alternative for generating thrust on a watercraft.

SUMMARY OF SELECTED EXAMPLE EMBODIMENTS

Various watercraft components that include a fluid system are described herein.

An example embodiment of a watercraft that includes a fluid system has a hull, a sail, and a compressor. The hull has a bow and a stern. The sail is disposed between the bow and the stern. The sail has a first end, a second end disposed on the hull, a lengthwise axis, a central axis, a first side, a second side opposably facing the first side, and defines an injection opening, a suction opening, and a channel. The lengthwise axis extends from the first end to the second end. The central axis is disposed orthogonally to the lengthwise axis and between the first side and the second side. The suction opening is disposed on the second side and between the injection opening and the first side. The channel extends from the suction opening to the injection opening such that fluid can travel into the suction opening and exit the injection opening. The compressor is disposed within the channel.

Additional understanding of the exemplary watercraft components that include a fluid system can be obtained by review of the detailed description, below, and the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevation view of an example watercraft that includes a sail. The sail includes a fluid system.

FIG. 2 is a cross-sectional view of the sail shown in FIG. 1 taken along line A-A. FIG. 2 illustrates the positional relationship between the watercraft velocity and the fluid system.

FIG. 3 illustrates the resultant force of the flow condition of the sail shown in FIG. 2.

FIG. 4 is a sectional view of a sail of another example watercraft that includes a fluid system taken orthogonally to the lengthwise axis of the sail. FIG. 4 illustrates the positional relationship between the watercraft velocity and the fluid system.

FIG. 5 is a sectional view of a sail of another example watercraft that includes a fluid system taken orthogonally to the lengthwise axis of the sail. FIG. 5 illustrates the positional relationship between the watercraft velocity and the fluid system.

FIG. 6 is a sectional view of a sail of another example watercraft that includes a fluid system taken orthogonally to the lengthwise axis of the sail. FIG. 6 illustrates the positional relationship between the watercraft velocity and the fluid system.

FIG. 7 is a sectional view of a sail of another example watercraft that includes a fluid system taken orthogonally to the lengthwise axis of the sail. FIG. 7 illustrates the positional relationship between the watercraft velocity and the fluid system.

FIG. 8 is a sectional view of a sail of another example watercraft that includes a fluid system taken orthogonally to the lengthwise axis of the sail. FIG. 8 illustrates the positional relationship between the watercraft velocity and the fluid system.

FIG. 9 is a sectional view of a sail of another example watercraft that includes a fluid system taken orthogonally to the lengthwise axis of the sail. FIG. 9 illustrates the positional relationship between the watercraft velocity and the fluid system.

FIG. 10 is a sectional view of a sail of another example watercraft that includes a fluid system taken orthogonally to the lengthwise axis of the sail. FIG. 10 illustrates the positional relationship between the watercraft velocity and the fluid system.

FIG. 11 is a sectional view of a sail of another example watercraft that includes a fluid system taken orthogonally to the lengthwise axis of the sail. FIG. 11 illustrates the positional relationship between the watercraft velocity and the fluid system.

FIG. 12 is a sectional view of a sail of another example watercraft that includes a fluid system taken orthogonally to the lengthwise axis of the sail. FIG. 12 illustrates the positional relationship between the watercraft velocity and the fluid system.

FIG. 13 is a sectional view of a sail of another example watercraft that includes a fluid system taken orthogonally to the lengthwise axis of the sail. FIG. 13 illustrates the positional relationship between the watercraft velocity and the fluid system.

FIG. 14 is a sectional view of a sail of another example watercraft that includes a fluid system taken orthogonally to the lengthwise axis of the sail. FIG. 14 illustrates the positional relationship between the watercraft velocity and the fluid system.

FIG. 15 is a sectional view of a sail of another example watercraft that includes a fluid system taken orthogonally to the lengthwise axis of the sail. FIG. 15 illustrates the positional relationship between the watercraft velocity and the fluid system.

FIG. 16 is a sectional view of another example watercraft that includes a fluid system. FIG. 16 is a sectional view of a sail taken orthogonally to the lengthwise axis of the sail.

FIG. 17 is a sectional view of a sail of another example watercraft that includes a fluid system taken orthogonally to the lengthwise axis of the sail. FIG. 17 illustrates the positional relationship between the watercraft velocity and the fluid system.

FIG. 18 is a sectional view of a sail of another example watercraft that includes a fluid system taken orthogonally to the lengthwise axis of the sail. FIG. 18 illustrates the positional relationship between the watercraft velocity and the fluid system.

FIG. 19 is a partially broken away view of another example watercraft that includes a fluid system.

FIG. 20 is a sectional view of a current hydrofoil taken orthogonally to the lengthwise axis of the hydrofoil.

FIG. 21 is a sectional view of a hydrofoil that includes a fluid system taken orthogonally to the lengthwise axis of the hydrofoil.

FIG. 22 is a perspective view of an example watercraft that includes first and second hydrofoils. Each of the first and second hydrofoils includes a fluid system and is moveable between a first configuration and a second configuration. FIG. 22 illustrates the first and second hydrofoils in the first configuration.

FIG. 23 is a sectional view of a hydrofoil illustrated in FIG. 22.

FIG. 24 is another perspective view of the watercraft illustrated in FIG. 22. FIG. 23 illustrates the first and second hydrofoils in the second configuration.

FIG. 25 is a partial sectional view of the watercraft illustrated in FIG. 22.

FIG. 26 is a perspective view of another example watercraft that includes a hydrofoil. The hydrofoil includes a fluid system and is moveable relative to the hull.

FIG. 27 is a sectional view of another hydrofoil that includes a fluid system taken orthogonally to the lengthwise axis of the hydrofoil.

FIG. 28 is a sectional view of another hydrofoil that includes a fluid system taken orthogonally to the lengthwise axis of the hydrofoil.

FIG. 29 is a partial perspective view of another example watercraft that includes a hydrofoil. The hydrofoil includes a fluid system and is moveable relative to the hull.

FIG. 30 is a sectional view of a rudder of a watercraft that includes a fluid system taken orthogonally to the lengthwise axis of the rudder.

FIG. 31 is a sectional view of another rudder of a watercraft that includes a fluid system taken orthogonally to the lengthwise axis of the rudder.

FIG. 32 is a sectional view of a sail of another example watercraft that includes a fluid system taken orthogonally to the lengthwise axis of the sail.

FIG. 33 is a sectional view of a sail of another example watercraft that includes a fluid system taken orthogonally to the lengthwise axis of the sail.

FIG. 34 is an elevation view of another example watercraft that includes a fluid system.

FIG. 35 is a perspective view of another example watercraft that includes a fluid system.

FIG. 36 is an elevation view of another example watercraft that includes a fluid system.

FIG. 37 is a partial elevation view of another example watercraft that includes a fluid system.

FIG. 38 is a sectional view of a sail of another example watercraft that includes a fluid system taken orthogonally to the lengthwise axis of the sail. FIG. 38 illustrates the positional relationship between the watercraft velocity and the fluid system. FIG. 38 illustrates the compressor moving in a first direction.

FIG. 39 is another sectional view of the sail shown in FIG. 38. FIG. 39 illustrates the compressor moving in a second direction that is opposite the first direction.

DETAILED DESCRIPTION

The following detailed description and the appended drawings describe and illustrate various example embodiments of watercraft components that include a fluid system. The description and illustration of these examples are provided to enable one skilled in the art to make and use a watercraft component (e.g., sail, hydrofoil, hydrowing, rudder) that includes a fluid system. They are not intended to limit the scope of the claims in any manner. The invention is capable of being practiced or carried out in various ways and the examples described and illustrated herein are merely selected examples of the various ways of practicing or carrying out the invention and are not considered exhaustive.

FIGS. 1 and 2 illustrate an example watercraft 8 that includes a fluid system 10. FIG. 3 illustrates the resultant force of the flow condition of the sail shown in FIG. 2. The watercraft 8 has a hull 12, a sail 14, and a compressor 16. The hull 12 has a bow 18, a stern 20, a starboard side 17, and a port side 19. In the embodiment illustrated, the watercraft 8 is a boat 9. However, it is to be understood that the fluid systems described herein can be included on any suitable watercraft, vessel, or vehicle, and on any suitable component of a watercraft, vessel, or vehicle, in which it is desired to incorporate the fluid systems described herein. The fluid system 10 includes the sail 14 and the compressor 16.

The sail 14 is disposed between the bow 18 and the stern 20 and has a first end 22, a second end 24 disposed on the hull 12, a lengthwise axis 25, a central axis 27, a first side 26, a second side 28 opposably facing the first side 26, and defines an injection opening 30, a suction opening 32, an intermediate portion 34, and a channel 36. When the watercraft 8 is traveling through fluid (e.g., water), the first side 26 is a first, windward side 26 and the second side 28 is a second, leeward side 28. The lengthwise axis 25 extends from the first end 22 to the second end 24. The central axis 27 is disposed orthogonally to the lengthwise axis 25 and between the first side 26 and the second side 28 such that it divides the first and second sides 26, 28. The suction opening 32 is disposed on the second side 28 and between the injection opening 30 and the first side 26. The intermediate portion 34 is disposed on the second side 28 and between the injection opening 30 and the suction opening 32. The channel 36 extends from the suction opening 32 to the injection opening 30 such that fluid can travel into the suction opening 32 and exit the injection opening 30. During use, fluid is directed from the injection opening 30 on the second side 28 along the intermediate portion 34 and toward, or to, the suction opening 32.

A sail included on a watercraft can include any suitable sail having any suitable structural arrangement. Selection of a suitable sail and structural arrangement for a sail can be based on various considerations. Examples of sails considered suitable to include in a watercraft include rigid sails, flexible sails, and any other sail considered suitable for a particular embodiment. Examples of structural arrangements for sails include sails that have a cross-sectional shape that is circular, elliptical, define an airfoil, or an airfoil with a flap, and any other cross-sectional shape considered suitable for a particular embodiment.

The compressor 16 is disposed within the channel 36 between the suction opening 32 and the injection opening 30. The compressor 16 is in fluid communication with the injection opening 30 and the suction opening 32. The compressor 16 is moveable between an off state and an on state and has a suction port 40 and an injection port 42. A compressor can be operatively connected to any suitable portion of a device, system, or component of a watercraft on which a fluid system is disposed to provide power to the compressor (e.g., battery, electric motor) and to provide a mechanism for moving the compressor between the off state and the on state (e.g., one or more switches). Alternative embodiments can include a compressor that can vary the degree to which fluid is compressed through the channel within which the compressor is disposed.

The compressor 16 is attached to the sail 14 and is positioned such that the suction port 40 is directed toward a first portion of the channel 36 that extends from the suction opening 32 to the compressor (e.g., the suction port 40 is directed toward the suction opening 32) and the injection port 42 is directed toward a second portion of the channel 36 that extends from the injection opening 30 to the compressor 16 (e.g., the injection port 42 is directed toward the injection opening 30). In the off state, the compressor 16 does not draw any fluid through the channel 36. Alternatively, some fluid may be drawn through the channel, or in alternative embodiments a duct or plurality of ducts, via the pressure difference between the suction opening and the injection opening. In the on state, compressor 16 draws fluid through the suction opening 32, through the compressor 16, and pushes fluid out of the injection opening 30.

A compressor can be attached to a component of a watercraft (e.g., sail, hydrofoil, hydrowing, rudder) using any suitable technique or method of attachment and selection of a suitable technique or method of attachment between a compressor and a component of a watercraft can be based on various considerations, including the material(s) that forms the compressor. Examples of techniques and methods of attachment considered suitable include welding, fusing, using adhesives, mechanical connectors, and any other technique or method considered suitable for a particular embodiment. While the compressor 16 has been illustrated as directly attached to a component of a watercraft, alternative embodiments can include one or more compressors that are indirectly attached to a component of a watercraft.

A compressor included in a component of a watercraft can comprise any suitable device, system, or component capable of compressing a fluid and selection of a suitable compressor can be based on various considerations, such as the structural arrangement of a channel defined by a component of a watercraft within which the compressor is disposed. Examples of compressors considered suitable to include in a component of a watercraft include electric pumps, pneumatic pumps, hydraulic pumps, micro-pumps, fans, electric fans, compressors, micro-compressors, vacuums, blowers, and any other compressor considered suitable for a particular embodiment.

While the sail 14 has been illustrated as having a main body defining the injection opening 30, the suction opening 32, and the channel 36, alternative embodiments can include a sail that defines a void within which one or more ducts are included to define a portion, or the entirety of an injection opening, a suction opening, and/or a channel. Examples of ducts considered suitable to utilize in a fluid system are described in U.S. Pat. No. 10,683,076 by Zha and issued Jun. 16, 2020, which is incorporated by reference into this application in its entirety. For example, a sail can include an injection duct that defines an injection opening and extends from a compressor to the injection opening and/or a suction duct that defines a suction opening and extends from a compressor to the suction opening.

As shown in FIGS. 1 and 2, the sail 14 is disposed on the hull 12 vertically relative to the hull 12. The wind velocity acting on the sail is the apparent wind velocity ({right arrow over (V)}a). {right arrow over (V)}a is determined by the watercraft moving velocity vector {right arrow over (V)}s (e.g., watercraft 8 direction of travel) and the wind velocity vector {right arrow over (V)}w. The example shown in FIG. 2, the watercraft 8 is moving in the north direction, the wind is flowing toward the northwest direction, the apparent wind points to the west direction and the first, windward side 26 faces the apparent wind. The relationship among {right arrow over (V)}a, {right arrow over (V)}s, and {right arrow over (V)}w is {right arrow over (V)}w={right arrow over (V)}s+{right arrow over (V)}a or {right arrow over (V)}a={right arrow over (V)}w−{right arrow over (V)}s (Equation 1). Thus, the direction and magnitude of {right arrow over (V)}a depends on the direction and magnitude of {right arrow over (V)}w and {right arrow over (V)}s. As a result, {right arrow over (V)}a can be in any direction. In the example of FIG. 2, the injection opening 30 is disposed around the 12 o'clock position (e.g., on the central axis 27) or, stated otherwise, 90 degrees relative to the apparent wind velocity {right arrow over (V)}a. In some embodiments an injection opening can be slightly on the downstream second, leeward side 28.

The injection opening 30 is configured such that a jet of fluid 44 exits the injection opening 30 when the compressor 16 is in the on state. The jet of fluid 44 is considered a coflow jet 45 and is applied on the sail 14 on the second, leeward side 28. In the illustrated embodiment, the jet of fluid 44 exits the injection opening 30 tangentially relative to the sail 14 (e.g., intermediate portion 34) and in the same direction as the apparent wind (e.g., coaxially, about coaxially) when the compressor 16 is in the on state. However, alternative embodiment can include an injection opening that is configured such that a jet of fluid exits the injection opening at any suitable angle relative to a sail (e.g., intermediate portion) and/or relative to an apparent wind. In the embodiment shown, and when the watercraft 8 is moving and has a direction of travel, the sail 14 has a leading edge 46 and a trailing edge 48 opposably facing the leading edge 46. The injection opening 30 shown in FIG. 2 is disposed on the leading edge 46.

The suction opening 32 is configured such that fluid enters the suction opening 32 on the second, leeward side 28 when the compressor 16 is in the on state. In the illustrated embodiment, the fluid enters the suction opening 32 tangentially relative to the sail 14 (e.g., intermediate portion 34) when the compressor 16 is in the on state. However, alternative embodiment can include a suction opening that is configured such that a fluid enters the suction opening at any suitable angle relative to a sail (e.g., intermediate portion).

In the illustrated embodiment, the central axis 27 divides the first, windward side 26 and the second, leeward side 28. The position of the injection opening 30 is defined by the α_i angle, which is the angle between the central axis 27 and an injection opening axis 31, the position of which is exaggerated in FIG. 2 for clarity, that extends through the injection opening 30 and the lengthwise axis 25. The injection opening 30 is disposed on the injection opening axis 31 which is disposed at a first angle α_i relative to the central axis 27. The sign of α_i is defined by the injection opening 30 position relative to the central axis 27 between the first, windward side 26 and the second, leeward side 28. If the injection opening 30 is disposed on the central axis 27 (e.g., 12 o'clock position) α_i=0°. If the injection opening 30 is disposed on the second, leeward side 28 α_i>0. If the injection opening 30 is disposed on the first, windward side α_i<0. In the embodiment shown in FIG. 2, the injection opening 30 is disposed on the central axis 27 (e.g., 12 o'clock position) and α_i=0°. However, alternative embodiments can include an injection opening 30 disposed at any suitable position relative to a central axis, a first side, a second side, or a suction opening, such as on a central axis, a second side between a central axis and a suction opening, or can include an injection opening axis disposed at any suitable angle relative to a central axis, such as angles equal to, greater than, less than, or about 120 degrees, angles between about-5 degrees and about 20 degrees, angles between about 0 degrees and about 10 degrees, and any other location or angle considered suitable for a particular embodiment.

The position of the suction opening 32 is defined by the α_s angle, which is the angle between the injection opening axis 31 and a suction opening axis 33 that extends through the suction opening 32 and the lengthwise axis 25. The suction opening 32 is disposed on the suction opening axis 33 which is disposed at a second angle α_s relative to the injection opening axis 31. In the embodiment shown in FIG. 2, the suction opening axis 33, α_s, is between about 110 degrees and about 135 degrees. However, alternative embodiments can include a suction opening 32 disposed at any suitable position relative to a central axis, a first side, a second side, an injection opening, an injection opening axis, on an axis, such as on a central axis, a second side between a central axis and an injection opening, or can include a suction opening axis disposed at any suitable angle relative to an injection opening axis, such as angles equal to, greater than, less than, or about 120 degrees, angles between about 10 degrees and about 270 degrees, angles between about 90 degrees and about 160 degrees, and any other location or angle considered suitable for a particular embodiment.

In the embodiment shown in FIG. 2, the fluid system 10 will generate a lift {right arrow over (L)} pointing to the north direction, the watercraft's 8 moving direction, as shown in FIG. 3. The lift thus becomes a thrust propelling the watercraft 8 moving forward. The drag generated by the sail 14 will be pointed to the west direction, in which the watercraft 8 has no motion and thus the drag does not do work to the watercraft 8. The resultant force of the sail 14 in FIG. 2 is Lift {right arrow over (L)} is always, or generally, normal to {right arrow over (V)}a, drag is always, or generally, parallel to {right arrow over (V)}a, as shown in FIG. 3, which illustrates the resultant force of the configuration in FIG. 2's flow condition.

FIG. 4 illustrates another example watercraft 108 that includes a fluid system 110. The watercraft 108 is similar to the watercraft 8 illustrated in FIGS. 1 through 3 and described above, except as detailed below. The fluid system 110 is similar to the fluid system 10 illustrated in FIGS. 1 through 3 and described above, except as detailed below. The watercraft 108 has a sail 114 and a compressor 116.

In the illustrated embodiment, the sail 114 is rotatable relative to a hull such that the central axis can continuously divide the first, windward side 126 and the second, leeward side 128 when the watercraft 108 is moving through a fluid. To achieve increased thrust using the fluid system 110, the resultant force on the watercraft 108 should be oriented in the watercraft's moving direction. As shown in FIG. 4, the watercraft's 108 moving direction is north. To achieve increased thrust, the sail 114 rotates about its lengthwise axis 125 achieving a favorable position relative to the apparent wind direction, shown as the apparent wind velocity {right arrow over (V)}a. As shown in FIG. 4, the wind velocity {right arrow over (V)}w is directed toward the northwest resulting in the apparent wind direction {right arrow over (V)}a being directed toward the northwest direction. In the embodiment shown in FIG. 4, the sail 114 has been rotated such that the injection opening 130 is located on the central axis 127 (e.g., α_i=0), which divides the first, windward side 126 and the second, leeward side 128 of the sail 114.

FIG. 5 illustrates another example watercraft 208 that includes a fluid system 210. The watercraft 208 is similar to the watercraft 108 illustrated in FIG. 4 and described above, except as detailed below. The fluid system 210 is similar to the fluid system 110 illustrated in FIG. 4 and described above, except as detailed below. The watercraft 208 has a sail 214 and a compressor 216.

In the illustrated embodiment, the apparent wind velocity {right arrow over (V)}a points in the southwest direction. The angle ϑ is defined as the angle between the apparent wind direction and watercraft moving direction. ϑ only has positive sign and is 0≤ϑ≤180°. ϑ is counted from the positive {right arrow over (V)}s direction and rotates to positive {right arrow over (V)}a pointing direction. The resultant force component in the watercraft moving direction will be F_s=L×sin(180°−ϑ)−D×cos(180°−ϑ)=L×sin ϑ+D×cos ϑ(Equation 2). For example, in FIG. 5 180°>ϑ>90°, the lift and drag will have the components canceling each other. Whereas, in FIG. 2 0°<ϑ<90°, the lift and drag will have the components adding to each other.

To increase thrust, the fluid systems described herein result in F_s>0, which is in the same direction of the watercraft's 208 moving direction. With F_s>0, the fluid systems described herein also result, or contribute to, making F_s/P as large as possible, where P is the fluid system's 210 power consumption.

FIG. 6 illustrates another example watercraft 308 that includes a fluid system 310. The watercraft 308 is similar to the watercraft 108 illustrated in FIG. 4 and described above, except as detailed below. The fluid system 310 is similar to the fluid system 110 illustrated in FIG. 4 and described above, except as detailed below. The watercraft 308 has a sail 314 and a compressor 316.

In the illustrated embodiment, the direction of the wind is to the northeast, resulting in {right arrow over (V)}w being directed to the northeast, the watercraft's 308 moving direction is north, resulting in {right arrow over (V)}s being directed to the north, and the direction of the apparent wind is to the east, resulting in {right arrow over (V)}a being directed to the east.

As described herein, the jet of fluid 344 is applied on the second, leeward side 328 of the sail 314, which is opposite the first, windward side 326 on which the apparent wind is applied. As shown in FIG. 6, the injection opening 330 is disposed on the central axis 327 and the suction opening 332 is disposed on the second, leeward side 328.

FIG. 7 illustrates another example watercraft 408 that includes a fluid system 410. The watercraft 408 is similar to the watercraft 108 illustrated in FIG. 4 and described above, except as detailed below. The fluid system 410 is similar to the fluid system 110 illustrated in FIG. 4 and described above, except as detailed below. The watercraft 408 has a sail 414 and a compressor 416.

In the illustrated embodiment, the direction of the wind is to the northeast, resulting in {right arrow over (V)}w being directed to the northeast, the watercraft's 408 moving direction is north, resulting in {right arrow over (V)}s being directed to the north, and the direction of the apparent wind is to the northeast, resulting in {right arrow over (V)}a being directed to the northeast.

As described herein, the jet of fluid 444 is applied on the second, leeward side 428 of the sail 414, which is opposite the first, windward side 426 on which the apparent wind is applied. As shown in FIG. 7, the injection opening 430 is disposed between the central axis 427 and the suction opening 432, which is disposed on the second, leeward side 428.

FIG. 8 illustrates another example watercraft 508 that includes a fluid system 510. The watercraft 508 is similar to the watercraft 108 illustrated in FIG. 4 and described above, except as detailed below. The fluid system 510 is similar to the fluid system 110 illustrated in FIG. 4 and described above, except as detailed below. The watercraft 508 has a sail 514 and a compressor 516.

In the illustrated embodiment, the direction of the wind is to the northeast, resulting in {right arrow over (V)}w being directed to the northeast, the watercraft's 508 moving direction is north, resulting in {right arrow over (V)}s being directed to the north, and the direction of the apparent wind is to the southeast, resulting in {right arrow over (V)}a being directed to the southeast.

As described herein, the jet of fluid 544 is applied on the second, leeward side 528 of the sail 514, which is opposite the first, windward side 526 on which the apparent wind is applied. As shown in FIG. 8, the injection opening 530 is disposed on the central axis 527 and the suction opening 532 is disposed on the second, leeward side 528.

FIG. 9 illustrates another example watercraft 608 that includes a fluid system 610. The watercraft 608 is similar to the watercraft 108 illustrated in FIG. 4 and described above, except as detailed below. The fluid system 610 is similar to the fluid system 110 illustrated in FIG. 4 and described above, except as detailed below. The watercraft 608 has a sail 614 and a compressor 616.

In the illustrated embodiment, the direction of the wind is to the northeast, resulting in {right arrow over (V)}w being directed to the northeast, the watercraft's 608 moving direction is north, resulting in {right arrow over (V)}s being directed to the north, and the direction of the apparent wind is to the northeast, resulting in {right arrow over (V)}a being directed to the northeast.

As described herein, the jet of fluid 644 is applied on the second, leeward side 628 of the sail 614, which is opposite the first, windward side 626 on which the apparent wind is applied. As shown in FIG. 9, the injection opening 630 is disposed on the central axis 627 and the suction opening 632 is disposed on the second, leeward side 628.

FIG. 10 illustrates another example watercraft 708 that includes a fluid system 710. The watercraft 708 is similar to the watercraft 108 illustrated in FIG. 4 and described above, except as detailed below. The fluid system 710 is similar to the fluid system 110 illustrated in FIG. 4 and described above, except as detailed below. The watercraft 708 has a sail 714 and a compressor 716.

In the illustrated embodiment, the direction of the wind is to the northeast, resulting in {right arrow over (V)}w being directed to the northeast, the watercraft's 708 moving direction is north, resulting in {right arrow over (V)}s being directed to the north, and the direction of the apparent wind is to the southeast, resulting in {right arrow over (V)}a being directed to the southeast.

As described herein, the jet of fluid 744 is applied on the second, leeward side 728 of the sail 714, which is opposite the first, windward side 726 on which the apparent wind is applied. As shown in FIG. 10, the injection opening 730 is disposed on the central axis 727 and the suction opening 732 is disposed on the second, leeward side 728.

FIG. 11 illustrates another example watercraft 808 that includes a fluid system 810. The watercraft 808 is similar to the watercraft 8 illustrated in FIGS. 1 through 3 and described above, except as detailed below. The fluid system 810 is similar to the fluid system 10 illustrated in FIGS. 1 through 3 and described above, except as detailed below. The watercraft 808 has a sail 814 and a compressor 816.

In the illustrated embodiment, the sail 814 a lengthwise axis 825, a central axis 827, a first side 826, a second side 828 opposably facing the first side 826, and defines a first injection opening 830, a second injection opening 850, a first suction opening 832, a second suction opening 852, a first intermediate portion 834, a second intermediate portion 854, and a channel 836. The first injection opening 830 and the first suction opening 832 are defined on the second side 828. The second injection opening 850 and the second suction opening 852 are defined on the first side 826.

As shown in FIG. 11, the channel 836 bifurcates between the compressor 816 and the first and second injection openings 830, 850, bifurcates between the compressor 816 and the first and second suction opening 832, 852, and extends from the compressor 816 to the first injection opening 830, the second injection opening 850, the first suction opening 832, and the second suction opening 852. When the compressor 816 is in the on state, fluid can travel into the first suction opening 832 and exit the first injection opening 830, can travel into the first suction opening 832 and exit the second injection opening 850, can travel into the first suction opening 832 and exit the first injection opening 830 and the second injection opening 850, can travel into the second suction opening 852 and exit the first injection opening 830, can travel into the second suction opening 852 and exit the second injection opening 850, can travel into the second suction opening 852 and exit the first injection opening 830 and the second injection opening 850, can travel into the first suction opening 832 and the second suction opening 852 and exit the first injection opening 850, can travel into the first suction opening 832 and the second suction opening 852 and exit the second injection opening 850, and/or can travel into the first suction opening 832 and the second suction opening 852 and exit the first injection opening 830 and the second injection opening 850.

In the illustrated embodiment, this is accomplished using a first plate 860, a second plate 862, a third plate 864, and a fourth plate 866. This structural arrangement allows the fluid system 810 to accommodate the apparent wind from two sides (e.g., east and west, north and south). When the jet of fluid 844 needs to be directed to the second side 828, the second plate 862 will rotate about an axis 2 until it is positioned in the 2-3 position to close the second injection opening 850. The first plate 860 will be in the open position 1-1′ to let the air flow out at the first injection opening 830. With respect to the suction openings 832, 852, the third plate 864 will rotate about an axis 4 until it is positioned in the 4-6 position to close the second suction opening 852. The fourth plate 866 will be in the open position 5-5′ to let fluid flow into the compressor 816. Vice versa, when jet of fluid 844 needs to be on the first side 826, the first plate 860 will be in 1-3 position to close the first injection opening 830 and the second plate 862 will move to the open position of 2-2′ to let fluid flow through the second injection opening 850. With respect to the suction openings 832, 852, the fourth plate 866 will rotate to the position 5-6 to close the first suction opening 852. The third plate 864 will rotate to the open position 4-4′ to open the second suction duct 852 and allow fluid to be sucked into the channel 836 to flow into the compressor 816.

As shown in FIG. 11, the sail 814 has an outer surface 868 on the first side 826 that is disposed a first distance from the lengthwise axis 825. The first intermediate portion 834 and the second intermediate portion 854 are each disposed a second distance, which is less than the first distance, from the lengthwise axis 825 such that they are each recessed relative to the outer surface 868 of the sail 814. This structural arrangement allows the jets of fluid 844 to be tangential to the surface of the intermediate portions 834, 854 and to facilitate the flow suction. An intermediate portion can be recessed any suitable amount Δ, which can be in the range of 0%-2% D, where D is the local diameter of a sail along the span. If Δ=0, an intermediate portion will not be recessed. If Δ<0, an intermediate portion will extrude outward with larger radius than an outer surface. In general, Δ can be in the range of −1% D-5% D or Δ=0%-2% D. Thus, a sail can have a first radius from a lengthwise axis to an outer surface and a second radius from a lengthwise axis to an intermediate portion. The second radius can be different than, less than, greater than, or equal to the first radius. For example, a second radius can be between about 1% greater than the first radius and about 5% less than the first radius, can be between about 0% and about 2% less than the first radius, and any other radii considered suitable for a particular embodiment.

FIG. 12 illustrates another example watercraft 908 that includes a fluid system 910. The watercraft 908 is similar to the watercraft 808 illustrated in FIG. 11 and described above, except as detailed below. The fluid system 910 is similar to the fluid system 810 illustrated in FIG. 11 and described above, except as detailed below. The watercraft 908 has a sail 914 and a compressor 916. The sail 914 is rotatable relative to a hull, as described herein.

In the illustrated embodiment, the direction of the wind is to the northeast, resulting in {right arrow over (V)}w being directed to the northeast, the watercraft's 908 moving direction is north, resulting in {right arrow over (V)}s being directed to the north, and the direction of the apparent wind is to the east, resulting in {right arrow over (V)}a being directed to the east.

As shown in FIG. 12, the second plate 962 and the third plate 964 are closed. The first plate 960 and the fourth plate 966 are open. Since {right arrow over (V)}a is directed to the east, the windward and leeward division line is along the north/south axis. As a result, the sail 914 is rotated, as described herein, such that the first injection opening 930 is disposed along the central axis 927, which divides the first, windward side 926 and the second, leeward side 928. A sail 914 can rotate to any suitable angle (e.g., 0-360 degrees in any direction, clockwise or counterclockwise) to position an injection opening at a desired location (e.g., the windward/leeward division line, central axis). Subsequent to rotating a sail to a desired location, the sail can be fixed until further rotation is desired.

Additional plates can be included on a sail to further close an injection opening and/or suction opening. For example, FIG. 12 includes a plate 970 that closes the second injection opening 950 and a plate 972 that closes the second suction opening 952. These two plates 970, 972 can be stored inside the sail 914 on either side of an opening when the second injection opening 950 and the second suction opening 952 are in use. A mirrored configuration can also be implemented relative to the second side 928. Alternatively, an opening can remain open when not in use. However, this may slightly impact performance.

FIG. 13 illustrates another example watercraft 1008 that includes a fluid system 1010. The watercraft 1008 is similar to the watercraft 808 illustrated in FIG. 11 and described above, except as detailed below. The fluid system 1010 is similar to the fluid system 810 illustrated in FIG. 11 and described above, except as detailed below. The watercraft 1008 has a sail 1014 and a compressor 1016. The sail 1014 is rotatable relative to a hull, as described herein.

In the illustrated embodiment, the direction of the wind is to the northwest, resulting in {right arrow over (V)}w being directed to the northwest, the watercraft's 1008 moving direction is north, resulting in {right arrow over (V)}s being directed to the north, and the direction of the apparent wind is to the northwest, resulting in {right arrow over (V)}a being directed to the northwest.

The sail 1014 is rotated clockwise from the position shown in FIG. 12 such that the second injection opening 1050 is located at the central axis 1027 (e.g., windward-leeward division line). As shown in FIG. 13, the first injection opening 1030 and the first suction opening 1032 are closed by the first plate 1060 and the fourth plate 1066.

Additional plates can be included on a sail to further close an injection opening and/or suction opening. For example, FIG. 13 includes a plate 1074 that closes the first injection opening 1030 and a plate 1076 that closes the first suction opening 1032. These two plates 1074, 1076 can be stored inside the sail 1014 on either side of an opening when the first injection opening 1030 and the first suction opening 1032 are in use. Alternatively, an opening can remain open when not in use. However, this may slightly impact performance.

This structural arrangement, along with others described herein, allows a sail to meet all apparent wind flow directions by rotating the sail clockwise or counterclockwise to meet the varying apparent wind direction such that a jet of fluid is applied on the leeward side and the injection opening being used is located at, or near, a central axis (e.g., the leeward-windward division line) and directed toward, or adjacent to, the direction of the watercraft moving direction.

FIG. 14 illustrates another example watercraft 1108 that includes a fluid system 1110. The watercraft 1108 is similar to the watercraft 808 illustrated in FIG. 11 and described above, except as detailed below. The fluid system 1110 is similar to the fluid system 810 illustrated in FIG. 11 and described above, except as detailed below. The watercraft 1108 has a sail 1114 and a compressor 1116.

In the illustrated embodiment, the direction of the wind is to the northeast, resulting in {right arrow over (V)}w being directed to the northeast, the watercraft's 1108 moving direction is north, resulting in {right arrow over (V)}s being directed to the north, and the direction of the apparent wind is to the east, resulting in {right arrow over (V)}a being directed to the east.

In the embodiment shown, the sail 1114 has an elliptical cross-sectional configuration. An ellipse can be described by equation: x²/a²+y²/b²=1 (Equation 3). Equation 3 includes 3 scenarios: 1) a<b (FIG. 14); 2); a=b: circle; 3) a>b.

In embodiments in which a sail has an elliptical cross-sectional, α_i can be any suitable angle, such as an angle between about 3 degrees and about 10 degrees, between about −5 degrees and about 30 degrees, and any other angle considered suitable for a particular embodiment.

In embodiments in which a sail has an elliptical cross-sectional, α_s can be any suitable angle, such as an angle between about 110 degrees and about 140 degrees, between about 90 degrees and about 170 degrees, angles about 120 degrees, and any other angle considered suitable for a particular embodiment. For elliptical cylinders, the first, windward side and second, leeward side division line can be one of the a axis or the b axis, or can be any line between the two axes.

FIG. 15 illustrates another example watercraft 1208 that includes a fluid system 1210. The watercraft 1208 is similar to the watercraft 808 illustrated in FIG. 11 and described above, except as detailed below. The fluid system 1210 is similar to the fluid system 810 illustrated in FIG. 11 and described above, except as detailed below. The watercraft 1208 has a sail 1214 and a compressor 1216.

In the illustrated embodiment, the direction of the wind is to the northeast, resulting in {right arrow over (V)}w being directed to the northeast, the watercraft's 1208 moving direction is north, resulting in {right arrow over (V)}s being directed to the north, and the direction of the apparent wind is to the east, resulting in {right arrow over (V)}a being directed to the east.

FIG. 16 illustrates another example watercraft 1308 that includes a fluid system 1310. The watercraft 1308 is similar to the watercraft 8 illustrated in FIGS. 1 through 3 and described above, except as detailed below. The fluid system 1310 is similar to the fluid system 10 illustrated in FIGS. 1 through 3 and described above, except as detailed below. The watercraft 1308 has a sail 1314 and a compressor 1316.

In the illustrated embodiment, the sail 1314 has an airfoil cross-sectional shape (e.g., does not have a constant cross-sectional area along the central axis). Alternative embodiments can include a sail that has a conical cross-sectional shape (e.g., along its span). For example, a sail can have a larger section at a trailing edge (e.g., root) and smaller section at a leading edge (e.g., tip) and vice versa.

FIG. 17 illustrates another example watercraft 1408 that includes a fluid system 1410. The watercraft 1408 is similar to the watercraft 808 illustrated in FIG. 11 and described above, except as detailed below. The fluid system 1410 is similar to the fluid system 810 illustrated in FIG. 11 and described above, except as detailed below. The watercraft 1408 has a sail 1414, a first compressor 1416, and a second compressor 1416′.

In the illustrated embodiment, the sail 1414 has a first portion 1413 and a second portion 1415. Each of the first portion 1413 and the second portion 1415 have structural arrangement similar to the sail 814 shown in FIG. 11.

The first portion 1413 has a first portion lengthwise axis 1425, a first portion central axis 1427, a first portion first side 1426, a first portion second side 1428 opposably facing the first portion first side 1426, and defines a first portion first injection opening 1430, a first portion first suction opening 1432, a first portion first intermediate portion 1434, a first portion channel 1436, a first portion second injection 1450 opening, a first portion second suction opening 1452, a first portion second intermediate portion 1454. A first compressor 1416 is disposed within the channel 1436.

The second portion 1415 is disposed adjacent to the first portion 1413. The second portion 1415 has a second portion lengthwise axis 1425′, a second portion central axis 1427′, a second portion first side 1426′, a second portion second side 1428′ opposably facing the second portion first side 1426′, and defines a second portion first injection opening 1430′, a second portion first suction opening 1432′, a second portion first intermediate portion 1434′, a second portion second injection opening 1450′, a second portion second suction opening 1452′, a second portion second intermediate portion 1454′, and a second portion channel 1436′. A second compressor 1416′ is disposed within the channel 1436′.

The first portion 1413 is rotatable relative to a hull and moveable relative to the second portion 1415 and/or the second portion 1415 is rotatable relative to a hull and moveable relative to the first portion 1413. As shown in FIG. 17, a clearance gap 1480 is disposed between the first portion 1413 and the second portion 1415 such that they can rotate about their axis relative to one another.

In the illustrated embodiment, each of the first portion 1413 and the second portion 1415 is symmetrical about its line of symmetry. Each portion 1413, 1415 is positioned at an optimal angle such that the first side 1426, 1426′ is facing apparent wind. The central axis (e.g., windward-leeward line) is not a straight line through both portions 1413, 1415, but are two separate central axes 1427, 1427′ that can be coaxial or set at angles relative to one another.

FIG. 18 illustrates another example watercraft 1508 that includes a fluid system 1510. The watercraft 1508 is similar to the watercraft 1408 illustrated in FIG. 17 and described above, except as detailed below. The fluid system 1510 is similar to the fluid system 1410 illustrated in FIG. 17 and described above, except as detailed below. The watercraft 1508 has a sail 1514, a first compressor 1516, and a second compressor 1516′.

In the illustrated embodiment, the first central axis 1527 is not coaxial with the second central axis 1527′ (e.g., the first central axis 1527 is disposed at an angle relative to the second central axis 1527′). While both the first portion 1513 and the second portion 1515 have been illustrated as including a fluid system, alternative embodiments can include a fluid system on a first portion and/or a second portion of a sail.

FIG. 19 illustrates another example watercraft 1608 that includes a fluid system 1610. The watercraft 1608 is similar to the watercraft 8 illustrated in FIGS. 1 through 3 and described above, except as detailed below. The fluid system 1610 is similar to the fluid system 10 illustrated in FIGS. 1 through 3 and described above, except as detailed below. The watercraft 1608 has a sail 1614 and a plurality of compressors 1616.

In the illustrated embodiment, the sail 1614 includes a plurality of injection openings 1630 disposed along the length, or lengthwise axis 1625, of the sail 1614, a plurality of suction openings 1632 disposed along the length, or the lengthwise axis 1625 of the sail 1614, a plurality of channels 1636 disposed along the length, or the lengthwise axis 1625 of the sail 1614, and a plurality of compressors 1616 disposed along the length, or the lengthwise axis 1625 of the sail 1614. Each suction opening of the plurality of suction openings 1632 is disposed on the second side 1628 and between an injection opening of the plurality of injection openings 1630 and the first side 1626. While not shown, an intermediate portion can be disposed on the second side 1628 and between each injection opening of the plurality of injection openings 1630 and each suction opening of the plurality of suction openings 1632. Each channel of the plurality of channels 1636 extends from a suction opening of the plurality of suction openings 1632 to an injection opening of the plurality of injection openings 1630 such that fluid can travel through each channel of the plurality of channels 1636. A compressor of the plurality of compressors 1616 is disposed within each channel of the plurality of channels 1636.

Each channel can be separated from an adjacent channel by ΔS, which can be between 0 and about 2D, where D is the diameter of the sail 1614. As used herein, the term “diameter” refers to the length of a straight line passing from an exterior surface on one side of a body, element, or feature, through the center of the body, element, or feature, and to an exterior surface on a second side of the body, element, or feature and does not impart any structural configuration on the body, element, or feature. As used herein, the term “radius” refers to the length of a straight line passing from the center of the body, element, or feature to an exterior surface on a side of a body, element, or feature and does not impart any structural configuration on the body, element, or feature.

FIG. 20 illustrates a cross-section of a typical hydrofoil that generates lift in the direction normal to moving flow V_x. A hydrofoil is formed by stacking the hydrofoil to lift up a watercraft for drag reduction. Since a hydrofoil can have a higher ratio of L/D (lift to drag) it can effectively lift a watercraft up and reduce the drag and energy consumption to bring the system a benefit. This is a result of air density being much smaller than water density. A watercraft with more surface in the air will have an overall lower drag. However, a hydrofoil with a very high lift coefficient and high L/D ratio can be beneficial to reduce drag for all watercrafts, large or small, heavy or light. Hydrofoils that accomplish these objectives are described herein.

FIG. 21 is an example hydrofoil 1706 that can be included on a watercraft. The hydrofoil 1706 includes a fluid system 1710. The fluid system 1710 includes the hydrofoil 1706 and the compressor 1716.

The hydrofoil 1706 has a leading edge end 1722, a trailing edge 1724, a top 1726, a bottom 1728 opposably facing the top 1726, and defines an injection opening 1730, a suction opening 1732, an intermediate portion 1734, and a channel 1736.

The hydrofoil 1706 can be attached to a hull (e.g., between a bow and a stern). The injection opening 1730 is defined between the leading edge 1722 and the trailing edge 1724. The suction opening 1732 is defined between the injection opening 1730 and the trailing edge 1724. The channel 1736 extends from the suction opening 1732 to the injection opening 1730 such that fluid can travel into the suction opening 1732 and exit the injection opening 1730. A compressor 1716 is disposed within the channel 1736.

FIGS. 22 through 25 illustrate another example first hydrofoil 1806 included on a watercraft 1808. The first hydrofoil 1806 includes a fluid system 1810. In addition, FIGS. 22 through 25 illustrates a second hydrofoil 1806′ included on the watercraft 1808. The second hydrofoil 1806′ incudes a fluid system 1810′.

In the illustrated embodiment, and as described herein, the compressor 1816, 1816′ of each hydrofoil 1806, 1806′, when in the on state, sucks in a small amount of water near the trailing edge 1824, 1824′ through the suction opening 1832, 1832′, pressurizes the water, and ejects it tangent to the surface near the leading edge 1822, 1822′ via the injection opening 1830, 1832′.

In the embodiment shown, each of the first and second hydrofoils 1806, 1806′ is moveable between a first configuration, as shown in FIG. 22, and a second configuration, as shown in FIG. 24. In the first configuration, each of the first and second hydrofoils 1806, 1806′ has a first length 1807, 1807′ extending from a lengthwise axis 1811 of the hull 1812 and a majority of the hydrofoil 1806, 1806′ extends away from the hull 1812. In the second configuration, each of the first and second hydrofoils 1806, 1806′ has a second length 1809, 1809′ extending from the lengthwise axis 1811 of the hull 1812 that is less than the first length and the hydrofoils 1806, 1806′ are retracted within the hull 1812, or such that each of the hydrofoils 1806, 1806′ are disposed parallel to the lengthwise axis 1811 of the hull 1812.

Each of the hydrofoils 1806, 1806′ can be rotated about three axes (x, y, and z) around a supporting system at point 0. The supporting system can deploy the hydrofoils 1806, 1806′ to have the span access normal to the watercraft moving direction when the hydrofoils 1806, 1806′ are in use to lift up the watercraft. The hydrofoils 1806, 1806′ will generate lift L pointing upward to lift up the watercraft 1808. As shown in FIG. 25, the supporting system 1882 can have a hydraulic system to change the angle of attack (AOA) of the hydrofoils 1806, 1806′, α. AOA α is defined as the angle between water flow and the chord of a hydrofoil, as shown in FIG. 23. The AOA can be varied in the supporting system at location 0. For example, FIG. 25 shows a hydraulic actuator b whose length can be changed so that the hydrofoil rotates about axis Z. The hydrofoil is connected with beam “a” by a hinge on the hydro-wing surface. When the actuator b has extended its length, the hydrofoil will increase AOA. When the length of b is reduced, the hydrofoil's AOA will be decreased. The hydraulic system b is installed inside the supporting system at location 0. When the watercraft moving speed is low or the watercraft stops, the hydrofoils 1806, 1806′ can be retracted to be aligned with the watercraft body as shown in FIG. 24 by rotating the hydro-wings around axis y. The hydrofoils 1806, 1806′ retracted position can reduce drag and also facilitate the watercraft docking.

FIG. 26 illustrates another example hydrofoil 1906. The hydrofoil 1906 includes a fluid system 1910.

In the illustrated embodiment, when a hydrofoil 1906 has a long span, two struts 1984 can be used on each side of the watercraft 1908 hull 1912 to strengthen the hydrofoil structure. These struts 1984 can be a fix structure connected with the hydrofoil 1906 or moveable relative to the hull (e.g., retractable). They can be retracted into the watercraft 1908 hull 1912 when they are not used. When they need to be used, they can be extracted from the watercraft 1908 hull 1912 to lock with the hydrofoil 1906. A strut, or set of struts, can be used with a hydrofoil that includes a fluid system, or a hydrofoil that does not include a fluid system.

FIG. 27 illustrates another example hydrofoil 2006. The hydrofoil 2006 includes a fluid system 2010.

In the illustrated embodiment, the hydrofoil 2006 includes a first portion 2013 and a second portion 2015, each of which includes a fluid system 2010 similar to fluid system 1710. In the embodiment shown, the second portion 2015 is a single plain hinged portion that can be deflected about the hinge. While both portions have been illustrated as including a fluid system, a hydrofoil 2006′ can include a fluid system 2010′ on only a second portion 2015′, as shown in FIG. 28, on only a first portion, or on a first portion and/or a second portion. As shown in FIG. 27, the second portion 2015 is moveable relative to the first portion 2013, which is fixed. Changing the AOA can be accomplished by changing the second portion 2015 deflection angle β.

FIG. 29 is an example hydrowing 2106 that can be included on a watercraft 2108. The hydrowing 2106 includes a fluid system 2110, as described herein. In the embodiment illustrated, the hydrowing 2106 has a dihedral angle λ. The hydrowings span can be any curved shape with sweep angle. A hydrofoil and hydrowing can have any suitable structural arrangement, such as symmetrical or non-symmetrical about the chord.

FIG. 30 is an example rudder 2206 that can be included on a watercraft. The rudder 2206 includes a fluid system 2210, as described herein. The fluid system 2210 includes the rudder 2206 and a compressor 2216.

The rudder 2206 can be attached to a hull. The rudder 2206 has a leading edge 2222, a trailing edge 2224, and defines a first injection opening 2230, a first suction opening 2232, a second injection opening 2250, a second suction opening 2252, and a channel 2236. The first injection opening 2230 is defined between the leading edge 2222 and the trailing edge 2224. The second injection opening 2250 is defined between the leading edge 2222 and the trailing edge 2224. The first suction opening 2232 is defined between the first injection opening 2230 and the trailing edge 2224. The second suction opening 2252 is defined between the second injection opening 2250 and the trailing edge 2224. The channel 2236 extends from the first and second suction openings 2232, 2252 to the injection openings 2230, 2250 such that fluid can travel into the first and/or second suction openings 2232, 2252 and exit the first and/or second injection openings 2230, 2250. The compressor 2216 is disposed within the channel 2236. Optionally, only one side of the fluid system can be utilized at a time, or both sides of the fluid system can be utilized at the same time at the same magnitude, or different magnitudes.

This structural arrangement can increase the effectiveness of watercraft's rudder at low speed, reduce the rudder size, and thus reduce watercraft fuel consumption.

FIG. 31 is another example rudder 2306 that can be included on a watercraft. The rudder 2306 includes a first portion 2313 and a second portion 2315. Each of the first and second portions 2313, 2315 includes a fluid system 2310, similar to the fluid system 2210 described herein.

As shown in FIG. 31, the rudder 2306 is symmetric about the chord. Depending on the force that the rudder 2306 needs to generate, the first and second portions 2313, 2315 can be rotated about an axis on the first portion 2313 chord, or the second portion 2315 chord. For example, if the rudder 2306 needs to generate a control force pointing upward, the second portion 2315 will rotate clockwise and the first injection opening 2330′ and the first suction opening 2332′ on the top will be used and the compressor 2316′ moved to the on state and the second injection opening 2350′ and the second suction opening 2352′ on the bottom will be closed.

FIG. 32 illustrates another example watercraft 2408 that includes a fluid system 2410. The watercraft 2408 is similar to the watercraft 808 illustrated in FIG. 11 and described above, except as detailed below. The fluid system 2410 is similar to the fluid system 810 illustrated in FIG. 11 and described above, except as detailed below. The watercraft 2408 has a sail 2414 and a compressor 2416. The sail 2414 is rotatable relative to a hull, as described herein.

In some circumstances, it may be desirable to generate additional thrust using a fluid system (e.g., such as when there is weak wind and a sail does not generate much thrust from the wind). In these circumstances, the fluid system 2410 can be used to generate thrust. In this embodiment, the watercraft 2408 is moving in the direction identified by arrow 2409 and the wind is moving in the direction identified by arrows 2411.

The sail 2414 a lengthwise axis 2425, a central axis 2427, a first side 2426, a second side 2428 opposably facing the first side 2426, and defines a first injection opening 2430, a second injection opening 2450, a first suction opening 2432, a second suction opening 2452, a first intermediate portion 2434, a second intermediate portion 2454, and a channel 2436. The first injection opening 2430 and the first suction opening 2432 are defined on the second side 2428. The second injection opening 2450 and the second suction opening 2452 are defined on the first side 2426.

In the embodiment shown, the first plate 2460 is in the open configuration (e.g., 1-1′ position), the second plate 2462 is the closed configuration (e.g., 2-3 position), the third plate 2464 is in the open position (e.g., 4-4′ position), and the fourth plate 2466 is in the closed position (e.g., 5-6 position). As a result, air can flow through the second suction opening 2452 (e.g., on the first side 2426), through the channel 2436, is pressurized by the compressor 2416, and exits the first injection opening 2430 (e.g., on the second side 2428). While the plates have been shown in a particular configuration, each plate can move between an open and closed position, or be in a closed or open position, to accomplish a desired amount of thrust.

Overall, the fluid system 2410 will have the air mass flow sucked in from the windward side, A, pressurized by the compressor 2416, and be ejected out on the leeward side, B, opposite to the watercraft's 2408 moving direction (coaxially with the watercraft's 2408 moving direction). The fluid being ejected 2431 at the first injection opening 2430 is oriented in a direction that is opposite the direction of the watercraft's 2408 moving direction. Alternative embodiments can include an injection opening that ejects fluid tangentially to a sail.

As shown in FIG. 32, the channel 2436 converges from the compressor 2416 to the first injection opening 2430 to accelerate the fluid ejected 2431 from the fluid system 2410 through the first injection opening 2430, increasing the velocity and generating thrust. Any portion of a channel (e.g., portion from suction opening to compressor, portion from compressor to injection opening) can converge, diverge, or have a constant inside diameter.

FIG. 33 illustrates another example watercraft 2508 that includes a fluid system 2510. The watercraft 2508 is similar to the watercraft 2408 illustrated in FIG. 32 and described above, except as detailed below. The fluid system 2510 is similar to the fluid system 2410 illustrated in FIG. 32 and described above, except as detailed below. The watercraft 2508 has a sail 2514 and a compressor 2516. The sail 2514 is rotatable relative to a hull, as described herein.

In some situations, a watercraft and/or sail may experience a large drag. In these situations, relieving some of this drag can reduce the structure load and/or reduce the watercraft's drag. For example, when there is strong wind, such as the winds created in a hurricane, the strong wind load on a sail may damage the sail.

In the illustrated embodiment, the sail 2514 has a lengthwise axis 2525, a central axis 2527, a first side 2526, a second side 2528 opposably facing the first side 2526, and defines a first injection opening 2530, a second injection opening 2550, a first suction opening 2532, a second suction opening 2552, a first intermediate portion 2534, a second intermediate portion 2554, and a channel 2536. The first injection opening 2530 and the first suction opening 2532 are defined on the second side 2528. The second injection opening 2550 and the second suction opening 2552 are defined on the first side 2526.

In the embodiment shown, the first plate 2560 is in the open configuration (e.g., 1-1′ position), the second plate 2562 is the open configuration (e.g., 2-2′ position), the third plate 2564 is in the open position (e.g., 4-4′ position), and the fourth plate 2566 is in the open position (e.g., 5-5′ position). As a result, air can flow through second injection opening 2550, through the channel 2536, and exit the first injection opening 2530. In addition, air can flow through second suction opening 2552, through the channel 2536, and exit the first suction opening 2532.

FIG. 33 illustrates a configuration of a sail that can be used to relieve a wind load. Relative to the sail 2514, the strong wind is from left and is identified as arrows 2511. The compressor 2516 is in the off state. Since each of the plates 2560, 2562, 2564, and 2566 is in the open position, air can pass through the sail 2514 from the windward side to leeward side to relieve the dynamic load on the sail 2514. As shown in FIG. 33, the watercraft 2508 is moving in the headwind direction, as shown by arrow 2509. Alternatively, such a configuration can be used when a watercraft is moored in a marina or otherwise not moving.

FIG. 34 illustrates another example watercraft 2608 that includes a first fluid system 2610 and a second fluid system 2611. The watercraft 2608 is similar to the watercraft 8 illustrated in FIGS. 1 through 3 and described above, except as detailed below. Each of the fluid systems 2610, 2611 is similar to the fluid system 10 illustrated in FIGS. 1 through 3 and described above, except as detailed below. The watercraft 2608 has a first sail 2614 and a second sail 2615. Each of the sails 2614, 2615 is rotatable relative to a hull, as described herein. Alternative embodiments, however, can include a sail that is fixed relative to a hull.

In the illustrated embodiment, each of the sails 2614, 2615 has a cross-sectional area that varies along its length, has an outer diameter that varies along its length, and has an inner diameter that varies along its length. A sail included in a fluid system, such as a first sail and/or a second sail, can have any suitable outer diameter and/or inner diameter along its length, such as those that vary along the entire length of a sail, those that vary along a portion of the length of a sail, those that are constant along the entire length of a sail, those that are constant along a portion of the length of a sail, combinations of those described herein, and any other diameter considered suitable for a particular embodiment. As a result, and in these embodiments, a lengthwise axis does not need to be a straight line, but rather is a central axis that follows the center of a sail.

FIG. 35 illustrates another example watercraft 2708 that includes a first fluid system 2710 and a second fluid system 2711. The watercraft 2708 is similar to the watercraft 8 illustrated in FIGS. 1 through 3 and described above, except as detailed below. Each of the fluid systems 2710, 2711 is similar to the fluid system 10 illustrated in FIGS. 1 through 3 and described above, except as detailed below. The watercraft 2708 has a first sail 2714 and a second sail 2715. Each of the sails 2714, 2715 is fixed relative to a hull, as described herein, and can include any suitable fluid system, such as those described herein, or any combination of fluid system, as described herein. Alternative embodiments, however, can include a sail that is rotatable relative to a hull. The first sail 2714 includes the first fluid system 2710 and the second sail 2715 includes the second fluid system 2711.

As shown in FIG. 35, the diameter D of a sail 2714, 2715 can vary along its respective length 2725, which extends from the first end 2722 to its second end 2724. In the illustrated embodiment, each sail 2714, 2715 has a first portion S₁ and a second portion S₂. The first portion S₁ has a substantially constant diameter D1 and the second portion S₂ has a diameter that tapers from the first portion S₁ to a diameter D2 at the first end 2722. This structural arrangement reduces the aerodynamic loading at the first end 2722. The variation from D1 to D2 can have any suitable pattern, linear or non-linear. For example, D2 can be between 0 and 99% smaller than D1 and/or be between 0 and 10 times smaller than D1. Furthermore, the second portion S₂ can have any suitable length relative to the length 2725. For example, S₂ can have a length between 0% and 100% of the length 2725, a length greater than, less than, or about 70% of the length 2725, or any other length considered suitable for a particular embodiment. In embodiments in which a fluid system includes a non-cylindrical sail, D1 and D2 represent the larger axis or airfoil chord.

To further decrease the aerodynamic loading at the first end 2722, a plate 2728 can be installed on the top of a sail, as shown relative to sail 2714. The plate 2728 can have any suitable diameter D3, such as those substantially equal to (2*D1), where D1 is the diameter of the sail at the second end 2724, those equal to 0 to 50 times D1, or any other diameter considered suitable for a particular embodiment. In some embodiments, the plate 2728 can be rotated about the axis A1, using any suitable mechanism attached to the sail 2714 or hull 2712 and can be formed as a solid piece of material. Alternatively, the plate can include a plurality of holes through its thickness, which can be any suitable thickness. Examples of thicknesses considered suitable include thicknesses equal to, about, less than, or greater than 1 mm and 20 cm. A plate can have any structural configuration, such as circular, elliptical, or be configured as an airfoil.

FIG. 36 illustrates another example watercraft 2808 that includes a first fluid system 2810. The watercraft 2808 is similar to the watercraft 2708 illustrated in FIG. 35 and described above, except as detailed below. The fluid system 2810 is similar to the fluid system 2710 illustrated in FIG. 35 and described above, except as detailed below. The watercraft 2808 has a sail 2814 that includes the first fluid system 2810.

A sail that includes a fluid system can have any suitable length and diameter along its length. For example, the length of a sail can be between 30 meters and 100 meters and the diameter can be between 1 meter and 5 meters. The size of current sails makes it difficult to transport the sails, in particular using trucks on a road, when assembling a watercraft. As shown in FIG. 36, and to address these issues, a sail can be formed of a plurality of segments 2870, such as S1, S2, S3, and S4. While four segments are illustrated, any suitable number of segments can be included in a sail. Each segment included in a plurality of segments 2870 can include a plurality of fluid systems, each of which comprises an injection opening, a suction opening, a channel extending from the injection opening to the suction opening, and a compressor disposed within the channel, as described herein.

As shown in FIG. 36, the sail 2814 includes a spar 2872 disposed inside the sail 2814 along its length. The spar provides strength to the sail with the external aerodynamic load. Each segment of the plurality of segments 2870 can be transported to a ship and assembled by connecting all the segments together. Adjacent segments can be attached to one another using any suitable technique or method of attachment, such as welding, threaded connectors, latches, pins, or any other technique of method considered suitable for a particular embodiment. In the illustrated embodiment, adjacent segments are attached to one another using male and female threads and rotating one segment relative to the other. This method of attachment can also be used between the spar 2872 and a segment. Alternatively, in embodiments in which non-cylindrical segments 2910, 2912 are used to form a sail, attachment between adjacent segments can be made by using interlocking teeth 2914, as shown in FIG. 37.

FIGS. 38 and 39 illustrate another example watercraft 3008 that includes a fluid system 3010. The watercraft 3008 is similar to the watercraft 8 illustrated in FIGS. 1 through 3 and described above, except as detailed below. The fluid system 3010 is similar to the fluid system 10 illustrated in FIGS. 1 through 3 and described above, except as detailed below. The watercraft 3008 has a sail 3014 and a compressor 3016.

In the illustrated embodiment, the sail 3014 is rotatable relative to a hull such that the central axis 3027 can continuously divide the first, windward side 3026 and the second, leeward side 3028 when the watercraft 3008 is moving through a fluid.

As shown in FIG. 38, the watercraft's 3008 moving direction is north and the apparent wind velocity {right arrow over (V)}a is directed to the west. To achieve increased thrust, a first opening (e.g., injection opening) 3030 is located on the central axis 3027, which divides the first, windward side 3026 and the second, leeward side 3028 of the sail 3014. In the embodiment shown, the first opening 3030 is positioned on the north (e.g., 12 o-clock position) side of the sail 3014 and the second opening (e.g., suction opening) 3032 is positioned on the southwest (e.g., 8 o-clock position) side of the sail 3014.

As shown in FIG. 39, the watercraft's 3008 moving direction is north and the apparent wind velocity {right arrow over (V)}a is directed to the east. To achieve increased thrust, the sail 3014 rotates about its lengthwise axis 3025 (e.g., clockwise or counterclockwise) achieving a favorable position relative to the apparent wind direction {right arrow over (V)}a. As shown in FIG. 39, the sail 3014 has been rotated from the position shown in FIG. 38 such that the second opening, now injection opening, 3032 is located on the central axis 3027, which divides the first, windward side 3026 and the second, leeward side 3028 of the sail 3014. In the embodiment shown, the second opening 3032 is positioned on the north (e.g., 12 o-clock position) side of the sail 3014 and the first opening, now the suction opening, 3030 is positioned on the southeast (e.g., 4 o-clock position) side of the sail 3014.

In the embodiment shown, the compressor 3016 (e.g., fan) is positioned at about the center of the channel 3036 and sail 3014 and is moveable is a first direction (e.g., clockwise), as shown in FIG. 38, and a second direction (e.g., counterclockwise), as shown in FIG. 39. The second direction is opposite the first direction. While the compressor 3016 has been shown as positioned at about the center of the channel 3036 and the sail 3014, a compressor can be positioned at any suitable location within a channel and/or a sail, such as between a center of a channel and an injection opening, about the center of a channel, between a center of a channel and a suction opening, about a center of a sail, off a center of a sail, close to an inner wall of a sail, and any other location considered suitable for a particular embodiment. When the compressor 3016 is activated and moving in the first direction, the compressor sucks fluid through the second opening 3032, pressurizes the fluid, and ejects the pressurized fluid through the first opening 3030 (e.g., tangential to the outer surface of the sail 3014), as shown as a coflow jet 3045 in FIG. 38. When the compressor 3016 is activated and moving in the second direction, the compressor 3016 sucks fluid through the first opening 3030, pressurizes the fluid, and ejects the pressurized fluid through the second opening 3032 (e.g., tangential to the outer surface of the sail 3014), as shown as a coflow jet 3045 in FIG. 39.

The sail 3014 provides structure for addressing any change in the apparent wind velocity without the need for additional injection openings, suction openings, channels, and/or valves. To accomplish this, the sail 3014 can be rotated about its lengthwise axis 3025 such that it is properly positioned, as described herein, and the direction in which the compressor 3016 pushes fluid through the channel 3036 can be altered (e.g., reversed) as needed. For example, when the apparent wind direction is changed (e.g., from pointing to the west to the east), a sail can be rotated about its lengthwise axis (e.g., about 112-120 degrees clockwise) to position a second opening in the direction a watercraft is moving and fluid can be sucked through a first opening and ejected from the second opening, as described herein.

Those with ordinary skill in the art will appreciate that various modifications and alternatives for the described and illustrated embodiments can be developed in light of the overall teachings of the disclosure, and that the various elements and features of one example described and illustrated herein can be combined with various elements and features of another example without departing from the scope of the invention. Accordingly, the particular arrangement of elements disclosed herein have been selected by the inventor(s) simply to describe and illustrate examples of the invention and are not intended to limit the scope of the invention or its protection, which is to be given the full breadth of the appended claims and any and all equivalents thereof.

Claims

1. A watercraft that includes a fluid system comprising: a hull having a bow and a stern;a sail disposed between the bow and the stern, the sail having a first end, a second end disposed on the hull, a lengthwise axis, a central axis, a first side, a second side opposably facing the first side, and defining an injection opening, a suction opening, and a channel, the lengthwise axis extending from the first end to the second end, the central axis disposed orthogonally to the lengthwise axis and between the first side and the second side, the suction opening disposed on the second side and between the injection opening and the first side, the channel extending from the suction opening to the injection opening such that fluid can travel into the suction opening and exit the injection opening; anda compressor disposed within the channel.

2. The watercraft of claim 1, wherein the injection opening is disposed on an injection opening axis disposed at a first angle relative to the central axis; and wherein the first angle is between about −5 degrees and about 20 degrees.

3. The watercraft of claim 1, wherein the suction opening is disposed on a suction opening axis disposed at a second angle relative to the injection opening axis; and wherein the second angle is between about 10 degrees and about 270 degrees.

4. The watercraft of claim 1, wherein the injection opening is disposed on the central axis.

5. The watercraft of claim 1, wherein the injection opening is disposed on the second side between the central axis and the suction opening.

6. The watercraft of claim 1, wherein the sail includes an intermediate portion disposed on the second side and between the injection opening and the suction opening; wherein the injection opening is defined on the sail such that fluid exits the injection opening tangentially relative to the intermediate portion; andwherein the suction opening is defined on the sail such that fluid enters the suction opening tangentially relative to the intermediate portion.

7. The watercraft of claim 1, wherein when said watercraft is traveling through a fluid the sail has a windward side and a leeward side; wherein the central axis divides the windward side and the leeward side;wherein the first side of the sail is disposed on the windward side;wherein the second side of the sail is disposed on the leeward side; andwherein the injection opening is disposed on the leeward side of the sail.

8. The watercraft of claim 7, wherein the sail is rotatable relative to the hull such that the central axis continuously divides the windward side and the leeward side.

9. The watercraft of claim 1, wherein the sail has a main body; and wherein the injection opening, suction opening, and channel are defined by the main body of the sail.

10. The watercraft of claim 1, wherein when said watercraft is traveling through a fluid the sail has a windward side and a leeward side; wherein the windward side faces an apparent wind on said sail; andwherein the injection opening is defined on the sail such that fluid exits the injection opening about coaxially with the apparent wind.

11. The watercraft of claim 1, wherein the injection opening is disposed on the second side; wherein the sail defines a second injection opening and a second suction opening, the second injection disposed on the first side, the second suction opening disposed on the first side;wherein the channel bifurcates between the compressor and the injection opening and the second injection opening and extends from the compressor to the injection opening and the second injection opening; andwherein the channel bifurcates between the compressor and the suction opening and the second suction opening and extends from the compressor to the suction opening and the second suction opening such that fluid can travel into the suction opening and exit the injection opening, can travel into the suction opening and exit the second injection opening, can travel into the suction opening and exit the injection opening and the second injection opening, can travel into the second suction opening and exit the injection opening, can travel into the second suction opening and exit the second injection opening, can travel into the second suction opening and exit the injection opening and the second injection opening, can travel into the suction opening and the second suction opening and exit the injection opening, can travel into the suction opening and the second suction opening and exit the second injection opening, can travel into the suction opening and the second suction opening and exit the injection opening and the second injection opening.

12. The watercraft of claim 1, wherein the sail includes an intermediate portion disposed on the second side and between the injection opening and the suction opening; and wherein the sail has an outer surface on the first side;wherein the intermediate portion is recessed relative to the outer surface of the sail;wherein the sail has a first radius from the lengthwise axis to the outer surface; andwherein the sail has a second radius from the lengthwise axis to the intermediate portion, the second radius being different than the first radius.

13. The watercraft of claim 1, wherein the sail has a circular cross-sectional shape, an elliptical cross-sectional shape, or has an airfoil cross-sectional shape.

14. The watercraft of claim 1, wherein the sail has a length extending from the first end to the second end; wherein the injection opening comprises a plurality of injection openings disposed along the length of the sail;wherein the suction opening comprises a plurality of suction openings disposed along the length of the sail, each suction opening of the plurality of suction openings disposed on the second side and between an injection opening of the plurality of injection openings and the first side;wherein the channel comprises a plurality of channels disposed along the length of the sail, each channel of the plurality of channels extending from a suction opening of the plurality of suction openings to an injection opening of the plurality of injection openings such that fluid can travel through each channel of the plurality of channels; andwherein the compressor comprises a plurality of compressors, a compressor of the plurality of compressors disposed within each channel of the plurality of channels.

15. The watercraft of claim 1, wherein the sail has a first portion and a second portion, the first portion having the first end, the second end, the lengthwise axis, the central axis, the first side, the second side, and defining the injection opening, the suction opening, and the channel; and wherein the second portion is disposed adjacent to the first portion.

16. The watercraft of claim 15, wherein the first portion is rotatable relative to the hull and moveable relative to the second portion; and wherein the second portion is rotatable relative to the hull and moveable relative to the first portion.

17. The watercraft of claim 1, wherein the sail has a first portion and a second portion, the first portion having a first diameter and the second portion having a second diameter that tapers from the first portion to the first end.

18. A watercraft that includes a fluid system comprising: a hull having a bow and a stern;a sail disposed between the bow and the stern, the sail having a first end, a second end disposed on the hull, a lengthwise axis, a central axis, a first side, a second side opposably facing the first side, and defining an injection opening, a suction opening, and a channel, the lengthwise axis extending from the first end to the second end, the central axis disposed orthogonally to the lengthwise axis and between the first side and the second side, the suction opening disposed on the second side and between the injection opening and the first side, the channel extending from the suction opening to the injection opening such that fluid can travel into the suction opening and exit the injection opening; anda compressor disposed within the channel;wherein when said watercraft is traveling through a fluid the sail has a windward side and a leeward side;wherein the central axis divides the windward side and the leeward side;wherein the first side of the sail is disposed on the windward side;wherein the second side of the sail is disposed on the leeward side; andwherein the sail is rotatable relative to the hull such that the central axis continuously divides the windward side and the leeward side.

19. The watercraft of claim 18, wherein the injection opening is disposed on an injection opening axis disposed at a first angle relative to the central axis; and wherein the first angle is between about −5 degrees and about 20 degrees.

20. A watercraft that includes a fluid system comprising: a hull having a bow and a stern;a sail disposed between the bow and the stern, the sail having a first end, a second end disposed on the hull, a lengthwise axis, a central axis, a first side, a second side opposably facing the first side, and defining an injection opening, a suction opening, and a channel, the lengthwise axis extending from the first end to the second end, the central axis disposed orthogonally to the lengthwise axis and between the first side and the second side, the suction opening disposed on the second side and between the injection opening and the first side, the channel extending from the suction opening to the injection opening such that fluid can travel into the suction opening and exit the injection opening; anda compressor disposed within the channel;wherein the injection opening is disposed on an injection opening axis disposed at a first angle relative to the central axis, the first angle being between about −5 degrees and about 20 degrees; andwherein the suction opening is disposed on a suction opening axis disposed at a second angle relative to the injection opening axis, the second angle being between about 10 degrees and about 270 degrees.