Arrangements, duct arrangements and methods

Abstract

To provide arrangements and duct arrangements for affecting a fluid flow, specifically a liquid flow, and to provide crafts and methods.SOLUTION: A ducting arrangement (100) for affecting a liquid flow is provided, the ducting arrangement (100) comprising a first duct section (1000) arranged to receive the liquid flow, the first duct section (1000) defining a first direction (1006) through the first duct section (1000) from a liquid inlet end (1002) to a liquid outlet end (1004), and a second duct section (2000) defining a second direction (2006) through the second duct section (2000) from the liquid inlet end (1002) to the liquid outlet end (1004), the second duct section (2000) comprising a vortex generating surface, the vortex generating surface being arranged to induce a vortex in the liquid flow through the first duct section (1000), the ducting arrangement (100) further comprising a rotor housed in one of the duct sections.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001]

[0001] This disclosure relates to equipment and ducting equipment for influencing fluid flow, or specifically liquid flow, and related crafts and methods.

Background Art

[0002]

[0002] Aircraft and ships are equipped with components that are exposed to fluid flow or utilize fluid flow. Certain components are configured to interact with the fluid flow, including guiding it, to facilitate the generation of thrust or lift. Increasing or maintaining the magnitude of the generated thrust or lift while using an equal or lesser amount of fuel is important in reducing carbon emissions. Therefore, techniques for improving the interaction of fluids with craft components are of interest in this field.

[0003]

[0003] The interaction between craft components and fluid flow creates an area of disturbed flow (often turbulent), known as the wake, downstream of the craft. In many cases, the craft must maintain a safe distance so as not to be obstructed by the wake. Techniques for reducing or otherwise influencing the wake are of interest in this field.

[0004]

[0004] The interaction between craft components and fluid flow results in noise. Techniques for reducing or otherwise influencing the noise are of interest in this field, for example, to reduce interference with aquatic life in the field of ships or to reduce environmental noise in the field of aircraft.

[0005]

[0005] The object of the present invention is to provide improvements and / or its methods, and / or to address one or more of the problems described above or elsewhere, or at least to provide alternative systems and / or methods.

Summary of the Invention

[0006]

[0006] According to the present invention, there is provided an installation and a method as described in the appended claims. Other features of the present invention will become apparent from the dependent claims and the following description.

[0007]

[0007] According to a first aspect of the present invention, there is provided ducting for influencing a fluid flow, the ducting comprising a first duct section arranged to receive the fluid flow, the first duct section defining a first direction through the first duct section from a fluid inlet end to a fluid outlet end and a second duct section defining a second direction through the second duct section from the fluid inlet end to the fluid outlet end, the second duct section comprising a vortex generating surface arranged to induce a vortex in the fluid flow through the first duct section.

[0008]

[0008] The duct section is advantageous for guiding the fluid flow and housing components. Providing the vortex generating surface is beneficial for reducing and / or minimizing the size of the wake induced by the duct section. The vortex generating surface also improves the characteristics of the fluid flow so that, for example, the interaction with a subsequent rotor results in improved rotor efficiency and / or thrust generation. In one example, the vortex generating surface may be configured to interact with the fluid flow to induce a vortex such that the characteristics of the fluid flow include the magnitude of vorticity. In one example, the duct section interacts with the fluid flow to induce a first set of fluid characteristics and the vortex generating surface interacts with the fluid flow to induce a second set of fluid characteristics. The second set of fluid characteristics can include an increase in the magnitude of the vorticity of the fluid flow. Surprisingly and advantageously, in this way, the magnitude of the vorticity of the wake is reduced.

[0009]

[0009] The duct section may be a hollow cylinder, tube, or ring. The duct section may be a section or region of a larger duct, cylinder, tube, or ring. The cross-section of the duct may be of any shape, such as square or rectangular, but is typically arcuate, such as circular or elliptical.

[0010]

[0010] In one example, the vortex generating surface is configured to induce a plurality of spaced vortices. The spatial separation of the vortices can correspond to the shape of the vortex generating surface. The plurality of vortices may be periodic. In one example, the vortex generating surface comprises a series of protrusions. In one example, the protrusions are serrated and / or wavy. In one embodiment, the protrusions may have a length and a height. The length may extend between the sides of the protrusion. The series of protrusions may be substantially aligned. That is, the protrusions may be aligned laterally. The protrusions may be aligned only laterally, for example, extending only in one dimension or direction (e.g., along a line, edge, or curve) and not forming an array that extends within or across the 2D surface. The protrusions may be curved along their length. In one example, the spatial separation of the vortices may be proportional to the spatial separation of the protrusions. In one example, each protrusion is configured to induce a vortex in the fluid flow.

[0011]

[0011] The protrusions can project in a direction substantially opposite to the first direction. That is, the height may be parallel to the first direction, the protrusions may have a base and a tip, and the direction from the base to the tip is substantially opposite to the first direction. The bases of the protrusions may be aligned laterally. The series of protrusions may form at least a partially continuous wavy profile. That is, a waveform may be formed, which may be curved or serrated or mountain-shaped. The protrusions may be adjacent to each other such that there is no gap between the protrusions. The at least partially continuous wavy profile of the laterally aligned protrusions has been found to be a very advantageous configuration of the protrusions for inducing vortices in the fluid flow.

[0012]

[0012] In one example, the vortex generating surface is a ring or otherwise has a cross-sectional profile similar to a duct section. In this way, a vortex generating surface having a cross-sectional profile similar to a duct section can be provided. This is advantageous for inducing vortices in the fluid flow through the first duct section.

[0013]

[0013] In one example, the second duct section is attached to, thereby supported by, and / or integrally formed with the first duct section. The second duct section and the first duct section may be a single integrally formed unit. Alternatively, the second duct section and the first duct section may be separate components configured to be assembled to form a single unit.

[0014]

[0014] In this way, the second duct section can be attached to an existing first duct section, for example, by a retrofit process. In this way, a vortex generating surface can be provided on the existing first duct section. Alternatively, the first and second duct sections can be provided as an integrally formed unit. Thereby, the vortex generating surface can be positioned at an optimal position to interact with the fluid flow. Further, this structure results in a robust duct installation.

[0015]

[0015] In one example, the second duct section is aligned with and / or coaxial with the first duct section.

[0016]

[0016] Advantageously, in this way, the second duct section, and thus the vortex generating surface, is well positioned to interact with and affect the fluid flow in order to induce vortices within the fluid flow through the first duct section.

[0017]

[0017] In one example, the duct installation further comprises a rotor housed within the first duct section.

[0018]

[0018] The rotor can be used to generate power and / or propulsion. Duct facilities including the rotor improve rotor efficiency and lead to a reduction in the magnitude of the wake generated by the rotor. In one example, the rotor is a propeller and / or a turbine rotor. Advantageously, by housing the rotor in a duct, also known as a cylindrical shroud, the loss of thrust from the tip of the rotor blade is reduced. The ducted rotor can be significantly more efficient than an open rotor. Improved performance is observed because the outward flow carries more kinetic energy.

[0019]

[0019] Further advantages can be obtained. For example, by reducing rotor blade tip losses, the ducted rotor is more efficient at generating thrust than an open rotor of the same diameter, especially at low speeds and high static thrust levels. By appropriately sizing the duct work, the ducted rotor can be adjusted to allow the rotor to operate more efficiently at a higher airspeed than an open rotor. For the same static thrust, the ducted rotor has a smaller diameter than an open rotor, allowing for smaller equipment. The ducted rotor is quieter than an open rotor, which shields blade noise and reduces the tip speed and the intensity of the tip vortices contributing to noise generation. The ducted rotor can enable a limited amount of thrust vectoring, which is not very suitable for a normal propeller. The ducted rotor provides improved safety on the ground and in water.

[0020]

[0020] In relation to the above, the vortex generating surface contributes to the identified advantages in that it induces vortices in the flow through the duct and rotor, which improves rotor efficiency and leads to a reduction in the size of the wake. This alleviates or mitigates some of the known drawbacks of ducted rotors, such as loss of efficiency and increased design complexity, with respect to the exact clearance required between the blade tip and the duct in order to maintain good efficiency, particularly in ducted rotors. Thus, the combination of the vortex generating surface and the ducted rotor is particularly advantageous as the vortex generating surface can be used, inter alia, to offset the drawbacks of the ducted rotor.

[0021]

[0021] In one example, the second duct section is provided upstream of the first duct section along a first direction.

[0022]

[0022] In this way, the first duct section and the second duct section are separated along the first direction. Thereby, the vortices induced by the vortex generating surface reach the first passage section downstream. This is advantageous for reducing the wake induced by the duct section. This is also advantageous for reducing the wake induced by any component, such as a rotor, housed in the duct section and for improving rotor efficiency.

[0023]

[0023] In one example, the second duct section is provided at the leading edge of the first duct section. In one example, the vortex generating surface is provided at the leading edge of the first duct section.

[0024]

[0024] In this way, an improved interaction with the fluid flow is promoted. Further, in this way, vortices in a favorable orientation are induced. Further, the vortex generating surface can interact with the fluid flow before any downstream surface. The vortices induced by the vortex generating surface can then pass downstream, where the vortices present in the fluid flow can advantageously interact with downstream components to improve their efficiency and / or reduce the size of the wake.

[0025]

[0025] To avoid ambiguity, in the present invention, the vortex generating surface may not be present / may be missing at the trailing edge of the first duct section and / or any duct section. That is, away from the leading edge of the duct installation, for example, behind the leading edge, the vortex generating surface may not be present. In this way, the interaction with the fluid flow for generating vortices occurs only at the leading edge of the duct installation, which can bring about an improvement in flow characteristics or efficiency.

[0026]

[0026] In one example, the second duct section is provided upstream of the rotor along a first direction.

[0027]

[0027] Advantageously, the vortices induced in the fluid flow impinge on the rotor and interact with the wake flow generated by the rotor. This has been found to have the effect of improving the level of thrust or propulsive force generated by the rotor. In addition, this also results in an advantageous reduction in the size of the wake flow structure that follows the craft.

[0028]

[0028] In one example, the protrusions of the vortex generating surface protrude in a direction substantially opposite to the first direction.

[0029]

[0029] In this way, an improved interaction with the fluid flow is promoted. Furthermore, in this way, vortices in an advantageous orientation are induced.

[0030]

[0030] In one example, the first duct section interacts with the fluid flow to induce a first set of fluid characteristics, the vortex generating surface interacts with the fluid flow to induce a second set of fluid characteristics, and the second set of fluid characteristics includes an increase in the magnitude of the vorticity of the fluid flow. Surprisingly and advantageously, this facilitates a reduction in the magnitude of the vorticity of the wake flow.

[0031]

[0031] In one example, the vortex generating surface is configured to induce a plurality of spatially separated vortices, optionally periodic vortices, within the fluid flow. The spatially separated vortices are beneficial for reducing the magnitude of the vorticity of the wake flow and also for reducing drag.

[0032]

[0032] According to a second aspect of the present invention, there is provided an aircraft or a ship comprising the duct facility according to the first aspect of the present invention.

[0033]

[0033] The aircraft includes an airplane, a helicopter, a drone, or other flyable machines. The ship includes a boat, a ship, a hovercraft, and an unmanned watercraft capable of operating underwater. The ship also includes a floating platform such as an oil drilling rig having propulsion or energy generation capabilities by rotors.

[0034]

[0034] According to a third aspect of the present invention, there is provided a method of influencing a fluid flow, the method including generating vortices in the fluid flow using a second duct section having a vortex generating surface and receiving the fluid flow in a first duct section.

[0035]

[0035] According to a fourth aspect of the present invention, there is provided a facility for influencing a liquid flow (opposite to an air flow), the facility including a first section selectively configurable to provide a vortex generating surface for inducing vortices in the liquid flow.

[0036]

[0036] Such a facility is very advantageous in improving the efficiency of a ship propulsion system and further in reducing the magnitude of the wake generated by the ship. The selective configuration of the vortex generating surface allows the surface to be provided only when needed or desired, or within the required or desired range or extent.

[0037]

[0037] In one example, the facility further includes a second section, and the first section and the second section are movable relative to each other to provide a vortex generating surface.

[0038] In this way, the vortex generating surface need not always be provided, or may be movable to a particular position to increase or decrease its interaction with the fluid flow. This is beneficial for inducing vortices in the liquid flow only when necessary or desired, or to a necessary or desired extent or range.

[0039]

[0039] In one example, the vortex generating surface may be configured to interact with the liquid flow to induce vortices such that the characteristics of the liquid flow include the magnitude of vorticity. In one example, other surfaces of the installation interact with the liquid flow to induce a first set of liquid characteristics, and the vortex generating surface, when provided, interacts with the liquid flow to induce a second set of liquid characteristics. The second set of liquid characteristics can include an increase in the magnitude of the vorticity of the liquid flow. Surprisingly and advantageously, in this way, the magnitude of the vorticity of the wake is reduced.

[0040]

[0040] In one example, the first section is movable away from and / or towards the second section. For example, the first section may be extendable from the second section and / or storable within the second section. That is, the installation may be a nested or sleeve-like installation.

[0041]

[0041] In this way, the profile of the installation when the vortex generating surface is not provided can be minimized.

[0042]

[0042] In one example, the first section can be selectively configured to provide a vortex generating surface at the leading edge of the second section.

[0043]

[0043] In this way, the vortex generating surface can interact with the liquid flow in front of any downstream surface. The vortices induced by the vortex generating surface can then pass downstream, where the vortices present in the liquid flow can advantageously interact with downstream components to improve their efficiency and / or reduce the magnitude of the wake.

[0044]

[0044] In one example, the second section comprises a flow control surface, such as a fin, a rudder, a duct, and / or a rotor, and / or is a flow control surface.

[0045]

[0045] Generating a wake and inducing vortices that interact with the flow control surface can advantageously result in a reduction in the magnitude of the resulting wake. In one example, the flow control surface interacts with the liquid flow to induce a first set of liquid properties, and when provided, the vortex generating surface interacts with the liquid flow to induce a second set of liquid properties. The second set of liquid properties can include an increase in the magnitude of the vorticity of the liquid flow. Surprisingly and advantageously, in this way, the magnitude of the vorticity of the wake is reduced.

[0046]

[0046] In one example, the facility further comprises a controller configured to implement a selective configuration of the vortex generating surface.

[0047]

[0047] Providing a controller facilitates an automated facility and / or a facility configurable based on variables monitored by the controller.

[0048]

[0048] In one example, the controller is arranged to implement a selective configuration of the vortex generating surface in response to a user command, an input from a sensor facility (local to or remote from the facility), and / or one or more environmental conditions.

[0049]

[0049] The selective configuration of the vortex generating surface may thereby be implemented based on appropriate feedback or control only when necessary or desired.

[0050]

[0050] Alternatively, the selective configuration of the vortex generating surface may be somewhat passive, for example, moving to a particular configuration when the liquid properties (e.g., at an appropriate liquid pressure, temperature, salinity concentration, flow rate, etc.) force this change.

[0051]

[0051] In one example, the first section is selectively configurable to change the shape of the installation, thereby providing a vortex generating surface that induces a vortex in the liquid flow. In one example, the first section is selectively configurable to change the shape of the vortex generating surface. In one example, the first section is selectively configurable to vary the shape of the vortex generating surface, thereby providing a vortex generating surface that induces a vortex in the liquid flow.

[0052]

[0052] Advantageously, the first shape of the installation without the vortex generating surface may be optimized for specific operating characteristics, while the second shape of the installation with the vortex generating surface may be optimized for propulsion efficiency and / or wake reduction. Further, changing the shape of the vortex generating surface is advantageous for improving the propulsion efficiency to some extent or for reducing the wake size by the required or desired amount.

[0053]

[0053] In one example, the first section is selectively configurable between a first configuration in which the vortex generating surface is provided to induce a vortex having a first characteristic in the liquid flow and a second configuration in which the vortex generating surface is provided to induce a vortex having a second characteristic in the liquid flow.

[0054]

[0054] In one example, the second characteristic is greater than the first characteristic. For example, the first characteristic may be zero in magnitude and the second characteristic may be non-zero in magnitude, or the first characteristic may be non-zero in magnitude and the second characteristic may be a greater non-zero magnitude.

[0055]

[0055] In one example, the first section is selectively configurable to provide a vortex generating surface comprising a series of protrusions. In one example, the protrusions are serrated and / or wavy. In one example, the protrusions may have a length and a height. The length may extend between the sides of the protrusion. The series of protrusions may be substantially aligned. That is, the protrusions may be aligned laterally. The protrusions may be curved along their length.

[0056]

[0056] In one example, the first section is selectively configurable to provide a vortex generating surface that induces a plurality of spatially separated vortices, optionally periodic vortices, in the fluid flow. The spatially separated vortices are beneficial in reducing the magnitude of the vorticity of the wake and also in reducing the drag force.

[0057]

[0057] According to a fifth embodiment of the present invention, a ship equipped with a facility according to a fourth aspect of the present invention is provided.

[0058]

[0058] The ship includes boats, ships and hovercraft, and unmanned watercraft including those capable of operating underwater. The ship also includes floating platforms such as oil drilling rigs having propulsive force or energy generating ability by rotors.

[0059]

[0059] According to a sixth aspect of the present invention, a method of influencing a liquid flow in a facility comprising a first section selectively configurable to provide a vortex generating surface is provided, the method comprising configuring the first section to provide a vortex generating surface that induces vortices in the liquid flow.

[0060]

[0060] According to a seventh aspect of the present invention, a facility for influencing a fluid flow is provided, the facility comprising a first section selectively configurable to provide a vortex generating surface, the vortex generating surface comprising a series of laterally aligned protrusions for inducing vortices in the fluid flow.

[0061]

[0061] The laterally aligned protrusions are a very advantageous structure for inducing vortices in the fluid flow. The selective configuration of the first section for providing the vortex generating surface allows the vortex generating surface to be provided only when needed or desired.

[0062] Aligned horizontally can alternatively be defined or described as a protrusion that extends only in one dimension or direction (e.g., along a line, edge, or curve) and does not form an array that extends within or is distributed across a 2D surface. Also in this case, the facility may be advantageous for a particular application, for example with respect to inducing vortices in a fluid flow.

[0063]

[0063] In one example, the vortex generating surface can be configured to interact with a fluid flow to induce vortices such that the characteristics of the fluid flow include the magnitude of vorticity. In one example, a first section interacts with the fluid flow to induce a first set of fluid characteristics, and the vortex generating surface, when provided, interacts with the fluid flow to induce a second set of fluid characteristics. The second set of fluid characteristics can include an increase in the magnitude of the vorticity of the fluid flow. Surprisingly and advantageously, in this way, the magnitude of the vorticity of the wake is reduced.

[0064]

[0064] In one example, the protrusions are serrated and / or wavy. In one example, the protrusions may have a length and a height. The length may extend between the sides of the protrusion. Aligned horizontally may mean that a series of protrusions are aligned substantially side by side. The protrusions may be curved along their length.

[0065]

[0065] The protrusions can comprise a base and a tip. The bases of the protrusions may be aligned horizontally. A series of protrusions may form at least a partially continuous wavy profile. That is, a waveform may be formed, which may be curved or serrated or mountain-shaped. The protrusions may be adjacent to each other such that there are no gaps between them. It has been found that at least a partially continuous wavy profile of horizontally aligned protrusions is a very advantageous configuration of the protrusions for inducing vortices in a fluid flow.

[0066]

[0066] In one example, the facility further comprises a second section, and the first section and the second section are movable relative to each other to provide a vortex generating surface.

[0067]

[0067] In this way, the vortex generating surface need not always be provided or may be movable to a specific position to increase or decrease the interaction with the fluid flow. This is beneficial for inducing vortices in the liquid flow only when required or desired.

[0068]

[0068] In one example, the first section is movable away from and / or towards the second section. For example, the first section may be extendable from the second section and / or stowable within the second section.

[0069]

[0069] In this way, the profile of the installation when the vortex generating surface is not provided can be minimized.

[0070]

[0070] In one example, the first section is selectively configurable to provide a vortex generating surface at the leading edge of the second section.

[0071]

[0071] In this way, an improved interaction with the fluid flow is promoted. Further, in this way, vortices in a favorable orientation are induced. Further, the vortex generating surface can interact with the fluid flow ahead of any downstream surface. The vortices induced by the vortex generating surface can then pass downstream where the vortices present in the fluid flow can advantageously interact with downstream components to improve their efficiency and / or reduce the size of the wake.

[0072]

[0072] In one example, the second section comprises and / or is a flow control surface such as fins, rudders, ducts, and / or rotors.

[0073]

[0073] The flow control surfaces of aircraft and ships generate a wake. By inducing vortices that interact with the flow control surface, the size of the resulting wake can advantageously be reduced.

[0074] In one example, the facility further comprises a controller arranged to effect a selective configuration of the vortex generating surface.

[0075] Providing the controller facilitates an automated facility and / or a facility configurable based on variables monitored by the controller.

[0076] In one example, the controller is arranged to effect a selective configuration of the vortex generating surface in response to user commands, inputs from sensor facilities (local or remote to the facility), and / or one or more environmental conditions.

[0077] The selective configuration of the vortex generating surface may thereby be effected based on appropriate feedback or control only when needed or desired.

[0078] Alternatively, the selective configuration of the vortex generating surface may be somewhat passive, e.g., moving to a particular configuration when liquid properties (e.g., at an appropriate liquid pressure, temperature, salinity concentration, flow rate, etc.) force this change.

[0079] In one example, the facility comprises an actuator assembly operable to provide the vortex generating surface. The actuator may be mechanical (e.g., a piston) or fluidic (using fluid movement or fluid pressure to shape the surface).

[0080] Providing the actuator for the vortex generating surface ensures robust and reliable control of the vortex generating surface. The selective configuration of the vortex generating surface may thereby be effected by control of the actuator assembly to provide the vortex generating surface only when needed or desired.

[0081] In one example, the first section comprises an elastic membrane and an actuator assembly operable to adjust the profile of the elastic membrane to provide a vortex generating surface.

[0082] The elastic membrane has a smooth profile, which aids in reducing drag. Further, the profile of the elastic profile can be manipulated to provide a vortex generating surface of a particular shape that is advantageous in achieving a required or desired level of reduction in the size of the wake and / or improvement in rotor efficiency.

[0083] In one example, the first section is formed from a shape memory alloy.

[0084] The shape memory alloy can be repeatedly reformed to provide a vortex generating surface of a desired shape. In this case, the actuator assembly may not be necessary, enhancing the reliability of the provision of the vortex generating surface and simplifying the structure.

[0085] In one example, the first section is selectively configurable between a first configuration in which the vortex generating surface is provided to induce vortices having a first characteristic in the fluid flow and a second configuration in which the vortex generating surface is provided to induce vortices having a second characteristic in the fluid flow.

[0086] In one example, the second characteristic is greater than the first characteristic. For example, the first characteristic is a magnitude of zero and the second characteristic is a non-zero magnitude, or the first characteristic is a non-zero magnitude and the second characteristic is a greater non-zero magnitude.

[0087] In one example, the first section is selectively configurable to provide a vortex generating surface that induces a plurality of spatially separated vortices, optionally periodic vortices, within the fluid flow. Spatially separated vortices are beneficial in reducing the magnitude of the vorticity of the wake and also in reducing drag.

[0088] According to an eighth aspect of the present invention, there is provided an aircraft or a ship equipped with the facility according to the seventh aspect of the present invention.

[0089]

[0089] The aircraft includes an airplane, a helicopter, a drone, or any other flyable machine. The ship includes a boat, a ship, and a hovercraft, and an unmanned watercraft capable of operating underwater. The ship also includes a floating platform such as an oil drilling rig having propulsion or energy generation capabilities by rotors.

[0090] According to a ninth aspect of the present invention, there is provided a method of influencing a fluid flow in a facility comprising a first section selectively configurable to provide a vortex generating surface comprising a series of laterally aligned protrusions, the method comprising configuring the first section to provide a vortex generating surface that induces vortices in the fluid flow.

[0091]

[0091] Any of the above-described aspects of the present invention can, if desired or appropriate, include any or all of the features of any or all of the other aspects of the present invention. This will be apparent to those skilled in the art from their own knowledge and the clearly closely related nature of all of the aspects and embodiments discussed herein.

Brief Description of the Drawings

[0092]

[0092] For a better understanding of the present invention and to show how embodiments of the present invention are put into practice, reference is made, by way of example, to the accompanying drawings.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

DETAILED DESCRIPTION OF THE INVENTION

[0093]

[0093] Referring to Figure 1, duct 1 is shown. Duct 1 is a hollow cylinder, tube, or ring. In this example, duct 1 is for housing or otherwise surrounding a rotor. In one exemplary embodiment, the rotor is a propeller rotor. In another exemplary embodiment, the rotor is a turbine rotor.

[0094]

[0094] Referring to Figures 2 and 3, duct equipment 100 is shown. Duct equipment 100 is for installation on an aircraft or a ship. The duct equipment includes a first duct section 1000 having a structure similar or identical to that of duct 1. That is, the first duct section 1000 is a hollow cylinder, tube, or ring. The first duct section 1000 is for housing or otherwise surrounding a rotor.

[0095]

[0095] The first duct section 1000 is arranged to receive a fluid flow therethrough. The first duct section 1000 comprises a fluid inlet end 1002 and a fluid outlet end 1004. The fluid inlet end 1002 is at the front or leading end of the first duct section 1000. The fluid outlet end 1004 is at the rear or trailing end of the first duct section 1000. The first duct section 1000 defines a first direction (indicated by arrow 1006) through the first duct section 1000 from the fluid inlet end 1002 to the fluid outlet end 1004.

[0096]

[0096] The duct installation 100 further comprises a second duct section 2000. The second duct section 2000 comprises a fluid inlet end 2002 and a fluid outlet end 2004. The fluid inlet end 2002 is at the front, leading end of the second duct section 2000. The fluid outlet end 2004 is at the rear, trailing end of the second duct section 2000 and opens into the fluid inlet end 1002 of the first duct section 1000. The second duct section 2000 defines a second direction (indicated by arrow 2006) through the second duct section 2000 from the fluid inlet end 2002 to the fluid outlet end 2004. The second duct section 2000 is provided upstream of the first duct section 1000 along the first direction 1006. The second duct section 2000 is provided at the leading edge of the first duct section 1000. When the first duct section 1000 houses a rotor, the second duct section 2000 is provided upstream of the rotor along the first direction 1006.

[0097]

[0097] The first duct section 1000 and the second duct section 2000 are radially and circumferentially aligned (e.g., the circumferences are substantially the same and are aligned) and are coaxial. In this way, the first direction 1006 is substantially parallel to and substantially aligned with the second direction 2006.

[0098]

[0098] In some embodiments, the first duct section 1000 and the second duct section 2000 are formed separately. Each duct section is formed from a material well suited for the application in question and may typically be formed from a polymer, metal, etc. The first duct section 1000 and the second duct section 2000 are bolted, adhered, or otherwise fixed to each other, thereby being connected or attached. Thereby, the second duct section 2000 is supported by the first duct section 1000. In one embodiment, the second duct section 2000 is provided in portions of the duct section, and each portion is bolted to the first duct section 1000, thereby forming the second duct section 2000. In another embodiment, the first duct section 1000 includes a thread formed at the front end of the first duct section 1000, and the second duct section 2000 includes a corresponding thread provided at the rear end of the second duct section 2000. The corresponding threads are engagable to attach the first and second duct sections 1000, 2000. In other embodiments, the second duct section 2000 is integrally formed with the first duct section 1000. In this way, the second duct section 2000 is attached to the first duct section 1000 and supported by the first duct section 1000.

[0099]

[0099] To avoid concerns, in some exemplary embodiments, the duct section may be only a region of a larger duct, tube, or ring.

[0100]

[0100] The second duct section 2000 includes a vortex generating surface 3000. Vortex generators are known. Conventional vortex generators are typically aerodynamic devices with fixed wings. Conventional vortex generators are attached to the lift surfaces of aircraft or to turbine blades.

[0101]

[0101] The vortex generating surface 3000 is arranged to induce vortices in the fluid flow through the first duct section 1000. The vortex generating surface 3000 comprises a plurality of protrusions 3002. The term "protrusion" is intended to include projections, serrations and / or undulations and the like. Each protrusion has a transverse circumferential length 3008 (which may be described as a "wavelength" or a part of a wavelength) and an axial height 3010 (which may be described as an "amplitude"). The protrusions 3002 project in a direction substantially opposite to the first direction 1006.

[0102]

[0102] In the absence of the vortex generating surface 3000, the duct sections 1000, 2000 interact with the fluid flow to induce a first set of fluid characteristics. The vortex generating surface 3000 provided within the duct installation 100 interacts with the fluid flow to induce a second set of fluid characteristics, and the second set of fluid characteristics includes an increase in the magnitude of the vorticity of the fluid flow. The vortex generating surface 3000 is configured to induce a plurality of periodically spaced vortices corresponding to the shape of the vortex generating surface 3000 and the spacing of the protrusions 3002.

[0103]

[0103] The generation of vortices by the vortex generating surface 3000 helps to reduce the magnitude of the vorticity of the wake flow generated by both the interaction between the duct installation 100 and the fluid flow and the interaction of a rotor (not shown) housed within the duct installation 100. In addition, the flow separation on the outer surfaces of the first and second duct sections 1000, 2000 is reduced compared to a ducted propulsion unit without a vortex generating surface 3000. This advantageously results in an increase in thrust generation for an equivalent energy input. Overall, this provides a more efficient propulsion unit, control of the turbulent wake, and reduction of downstream swirling motion. Furthermore, improved bollard pull performance is achieved, the occurrence of cavitation is suppressed, and underwater radiated noise is reduced.

[0104]

[0104] In the exemplary embodiments illustrated in FIGS. 2 and 3, the vortex generating surface 3000 comprises a series of laterally aligned protrusions 3002. The laterally aligned protrusions 3002 mean that they are aligned side by side. That is, the protrusions are adjacent to each other. Here, the protrusions are aligned to form a continuous surface 3004 having a leading edge 3006. The alignment of the protrusions 3002 results in the frontmost points of each protrusion being aligned in a plane. In this case, the plane is a plane perpendicular to the central longitudinal axes of the first and second duct sections 1000, 2000.

[0105]

[0105] The leading edge 3006 has a continuous wavy profile generated by the rise and fall of the plurality of protrusions 3002. The terms "wavelength" and "amplitude" used to describe the dimensions of the protrusions 3002 are particularly appropriate here. The wavelength is indicated by 3008 and the amplitude is indicated by 3010. The protrusions 3002 are curved along their length such that, as shown in the figure, the protrusions 3002 together form a ring of laterally aligned protrusions 3002. It is noted that the protrusions extend around the circumference of the duct rather than along the duct (e.g., not along the inner or outer surface of the duct). This can improve performance and / or simplify the structure.

[0106]

[0106] Referring to FIGS. 4 and 5, an installation 110 is shown. The installation 110 is for installation on an aircraft or a ship. The installation 110 is for influencing a fluid flow. In one exemplary embodiment, the installation 110 has an overall structure similar to the duct installation 100 described above. That is, the installation 110 can include duct sections. However, the installation 110 also has applications in sections other than ducts and flow control surfaces.

[0107]

[0107] In the apparatus 110, the first section 1100 can be selectively configured to provide a vortex generating surface 3100. The vortex generator 3100 is provided to induce vortices in the fluid flow. In an exemplary embodiment, the fluid flow is a liquid flow (e.g., as contrasted with an air flow).

[0108]

[0108] The provided vortex generating surface 3100 comprises a plurality of protrusions 3102. The term "protrusion" is intended to include serrations and / or undulations. As described above, each protrusion has a length (which may be described as the "wavelength") and a height (which may be described as the "amplitude"). The protrusions 3002 project in a direction substantially opposite to the first direction 1106.

[0109]

[0109] In this way, the apparatus 110 can be configured in a configuration where the vortex generating surface is not provided, thereby not interacting with the fluid flow to induce vortices in the fluid flow. The apparatus 110 can be selectively configured in a configuration where the vortex generating surface 3100 is provided, thereby interacting with the fluid flow and inducing vortices therein. The apparatus 110 can be selectively configured in a configuration where the vortex generating surface 3100 is provided to a certain extent or degree (e.g., partially), thereby interacting with the fluid flow and inducing vortices therein to a certain extent or degree. Advantageously, this enables the apparatus 110 to be configured to provide the vortex generating surface 3100 when it is desirable or necessary to induce vortices in the fluid flow using the vortex generating surface 3100. Advantageously, this also enables the vortex generating surface 3100 to be removed or otherwise not provided to interact within the fluid flow, which can be beneficial for reducing drag or increasing post-craft flow when appropriate. These advantages were not contemplated or achievable, particularly in a liquid (e.g., water) environment. Considering the possible advantages from such applications, this is surprising.

[0110]

[0110] As described above, the vortex generating surface 3100 provided within the installation 110 interacts with the fluid flow to induce a second set of fluid characteristics, which includes an increase in the magnitude of the vorticity of the fluid flow. The vortex generating surface 3100 is configured to induce a plurality of periodic, spaced vortices corresponding to the shape of the vortex generating surface 3000 and the spacing of the protrusions 3002.

[0111]

[0111] The generation of vortices by the vortex generating surface 3100, when provided, serves to reduce the magnitude of the vorticity of the wake flow. In addition, the separation of the flow on the outer surfaces of the first and second sections 1100, 2100 is reduced compared to a propulsion unit without the associated vortex generating surface 3100. This advantageously results in an increase in thrust generation for an equivalent energy input. Overall, this provides a more efficient propulsion unit, control of turbulent wake flow, and reduction of downstream swirling motion. Further, improved bollard pull performance is achieved, the occurrence of cavitation is suppressed, and airborne / underwater radiated noise is reduced.

[0112]

[0112] The installation 110 further comprises a second section 2100. The first section 1100 and the second section 2100 are movable relative to each other so as to provide the vortex generating surface 3100.

[0113]

[0113] The installation 110 further comprises a controller 112. The controller 112 is arranged to effect a selective configuration of the vortex generating surface 3100. That is, in this exemplary embodiment, the controller 112 controls an actuator to extend or expand, or retract or contract, the vortex generating surface 3100 when it is necessary or desirable to provide the vortex generating surface 3100. For example, the controller can effect a selective configuration of the vortex generating surface 3100 as follows: a. User commands; b. Input from additional sensor equipment 114, for example, sensors operable to measure and detect turbulent flow, craft speed and / or fluid flow velocity or the like; and / or c. Environmental conditions, such as the level of turbulence, proximity to other crafts, time, altitude, or the like.

[0114]

[0114] The first section 1100 includes an elastic membrane 1102 and an actuator assembly 1104. The actuator assembly 1104 is operable to adjust the profile of the elastic membrane to provide a vortex-generating surface 3100.

[0115]

[0115] The elastic membrane 1102 is provided in a section that crosses the leading edge of the second section 2100. The actuator assembly 1104 includes a plurality of linear actuators, one actuator for each portion of the elastic membrane 1102. In the retracted position, the actuator extends so as to return into the second section 2100.

[0116]

[0116] By operating the actuator, the actuator extends away from the second section 2100 to contact the elastic membrane section and biases the elastic membrane section away from the second section 2100, thereby providing a vortex-generating surface 3100 having a series of protrusions at the leading edge of the second section 2100.

[0117]

[0117] The above-described embodiments include an actuator assembly 1104 and an elastic membrane 1102, but other structures that are selectively configurable to provide a vortex-generating surface are suitable. For example, in one exemplary embodiment, the first section includes a shape memory alloy, and the application of heat, such as heated fluid, deforms the shape memory alloy to provide a series of protrusions. In another exemplary embodiment, the first section can include a rigid protrusion member, and an elastic biasing means, or an actuator assembly actually similar to those described above, can extend the protrusion member from the second section and / or retract it into the second section.

[0118]

[0118] The advantages of the vortex generating surface are quantified with reference to the following non-limiting examples provided below. Although the examples provided relate to duct sections, those skilled in the art will understand that similar advantages can be obtained by using the vortex generating surface with other sections, and thus will understand that the advantages of both installations 100, 110 are illustrated.

[0119]

[0119] Figures 6 and 8 show a first duct and a propeller interacting with a fluid flow. The duct and the propeller are shaped and sized to have a first set of geometric parameters. Those skilled in the art will understand that the geometric parameters suitable for the duct and propeller installations will depend on the specific application and use of the installation. The concentric rings surrounding the outside of the duct in Figure 6 indicate the drag force induced by the leading edge of the duct. In Figure 8, a ring-shaped wake pattern in the flow direction, indicated by a continuous ring surrounding the duct, can be seen.

[0120]

[0120] Figures 7 and 9 show a second duct and a propeller interacting with a fluid flow. The second duct and the propeller have the same geometric parameters as the first duct and the propeller of Figures 6 and 8. In Figures 7 and 9, in addition to the duct and the propeller, a vortex generating surface is provided at the leading edge of the duct.

[0121]

[0121] As can be seen in Figure 7, the regions of drag force are compartmentalized at periodic intervals around the circumference of the duct. This is due to the provision of the vortex generating surface. As a result, this generates less overall drag force when compared to the duct and propeller of Example 1. In this example, the total drag force is reduced by 50%.

[0122]

[0122] As can be seen in Figure 9, vortices in the counter-rotating flow direction are induced by the vortex generating surface, which were not present in Example 1 above. As can be seen from the figure, the vortices are spatially separated, i.e., spaced apart, around the circumference of the duct. That is, the vortex generating surface is configured to induce a plurality of spaced-apart vortices. The induced vortices are periodic.

[0123]

[0123] The induced vortices assist in reducing the magnitude of the wake. Comparing FIGS. 6 and 7, the duct is shown to interact with the fluid flow to result in a first set of fluid characteristics (e.g., a first wake pattern), while the vortex generating surface interacts with the fluid flow to induce a second set of fluid characteristics (e.g., a second wake pattern). As shown in FIG. 9, the second set of fluid characteristics may surprisingly include an increase in the magnitude of the vorticity of the fluid flow that reduces the magnitude of the vorticity of the wake.

[0124]

[0124] Furthermore, the flow separation on the outer surface of the duct in Example 2 is lower than that in Example 1 as a result of providing the vortex generating surface. This advantageously results in an increase in thrust generation for an equivalent energy input. Overall, this provides a more efficient propulsion unit, control of the turbulent wake, and reduction of downstream swirling motion. Also, improved bollard pull performance is achieved, the occurrence of cavitation is suppressed, and underwater radiated noise is reduced.

[0125]

[0125] Referring to FIG. 10, a method of guiding a fluid flow is shown. Step S1000 includes generating vortices in the fluid flow using a second duct section having a vortex generating surface. Step S1002 includes receiving the fluid flow within a first duct section.

[0126]

[0126] Referring to FIG. 11, a method of influencing a liquid flow in a facility comprising a first section selectively configured to provide a vortex generating surface is shown. Step S2000 includes configuring the first section to provide a vortex generating surface that induces vortices in the liquid flow.

[0127]

[0127] Referring to FIG. 12, a method of influencing a fluid flow in a facility comprising a first section selectively configurable to provide a vortex generating surface comprising a series of laterally aligned protrusions is shown. Step S3000 includes configuring the first section to provide a vortex generating surface that induces vortices in the fluid flow.

[0128]

[0128] In some examples, the devices described herein can be fabricated or manufactured as completely new stand-alone entities. However, at least some implementations can be readily modified to achieve the above advantages, for example, by modifying a vortex-generating surface, such as that described herein, onto an existing flow acting surface or object, or by moving an existing vortex-generating surface to a different location, etc.

[0129]

[0129] As noted above, aspects and embodiments are closely related and interrelated, and it will be understood that different features of any one aspect or embodiment may be used in addition to, or instead of, the features of another aspect or embodiment.

[0130]

[0130] Although some preferred embodiments of the present invention have been shown and described, it will be recognized by those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the appended claims.

[0131]

[0131] The foregoing description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of the various embodiments of the present disclosure as defined by the claims and their equivalents. This includes various specific details to assist in that understanding, which should be regarded as merely exemplary. Accordingly, those skilled in the art will recognize that various changes and improvements can be made to the various embodiments described herein without departing from the spirit and scope of the present disclosure. Further, descriptions of known functions and configurations have been omitted for clarity and brevity.

[0132]

[0132] The terms and words used in the above description and claims are not limited to bibliographical meanings and are merely used by the inventor to enable a clear and consistent understanding of the present disclosure. Therefore, it will be apparent to those skilled in the art that the following description of various embodiments of the present disclosure is provided for illustrative purposes only and is not provided for the purpose of limiting the present disclosure as defined by the appended claims and their equivalents.

[0133]

[0133] Unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" should be understood to include plural referents. Terms such as "front", "rear", "side", "upper", "lower", "above", "below", "inside", "outside", and the like are used to refer to the device and its components in the orientation in which it is illustrated, which orientation is the intended orientation in which it is to be used, but should not be construed as limiting in other forms. Like reference numerals are used throughout the drawings to indicate like features, and these are not to scale.

[0134]

[0134] At least some of the exemplary embodiments described herein may be constructed, in part or whole, using dedicated special-purpose hardware. Terms such as "component", "module", or "unit" as used herein can include, but are not limited to, hardware devices such as circuits, field programmable gate arrays (FPGAs), or application specific integrated circuits (ASICs) in the form of individual or integrated components that perform a particular task or provide related functionality. In some embodiments, the elements described may be configured to exist on a tangible non-transitory addressable storage medium and may be configured to execute on one or more processors. These functional elements may, in some embodiments, include, by way of example, components such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. Exemplary embodiments have been described with reference to the components, modules, and units discussed herein, but such functional elements may be combined into fewer elements or separated into additional elements. It will be understood that various combinations of optional features are described herein and that the described features may be combined in any suitable combination. In particular, the features of any one exemplary embodiment may be combined with the features of any other embodiment, as needed, except where such combinations are mutually exclusive. Throughout this specification, the terms "comprising" or "comprises" mean including the specified component but not excluding other presence.

[0135] Attention is directed to all documents and writings that were filed, simultaneously with or before the filing of this specification, in connection with this application and that were published or otherwise made available to the public for inspection with this specification, and all such documents and writings are hereby incorporated by reference in their entirety into this specification.

[0136]

[0136] All features disclosed in this specification (including any appended claims, abstract, and drawings), and / or all steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive.

[0137]

[0137] Each feature disclosed in this specification (including any appended claims, abstract, and drawings) may be replaced by alternative features serving the same, equivalent, or similar purpose, unless expressly stated otherwise. Thus, each feature disclosed is only one example of a common general series of equivalent or similar features, unless expressly stated otherwise.

[0138]

[0138] The present invention is not limited to the details of the foregoing embodiments. The present invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any appended claims, abstract, and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. Ductwork for affecting liquid flow, comprising: a first duct section disposed to receive a liquid flow, the first duct section defining a first direction through the first duct section from a liquid inlet end to a liquid outlet end; a second duct section defining a second direction through the second duct section from a liquid inlet end to a liquid outlet end; the second duct section including a vortex generating surface arranged to induce vortices in the liquid flow through the first duct section; The ductwork further comprises a rotor housed in one of the duct sections.

2. The ductwork of claim 1 , wherein the rotor is housed in the first duct section.

3. The ductwork of claim 1 or 2, wherein the vortex generating surface comprises a series of protrusions.

4. The ductwork of claim 1 , 2 or 3, wherein the vortex generating surface is a ring.

5. 5. The ductwork of claim 1 , wherein the second duct section is attached to, supported by, and / or integrally formed with the first duct section.

6. 6. The ductwork of any preceding claim, wherein the second duct section is aligned with and / or coaxial with the first duct section.

7. Ductwork according to any one of claims 1 to 6, wherein the rotor is a propeller and / or a turbine rotor.

8. 8. The ductwork of any preceding claim, wherein the second duct section is provided upstream of the rotor along the first direction.

9. 9. The ductwork of any preceding claim, wherein the second duct section is provided upstream of the first duct section along the first direction.

10. 10. The ductwork of any preceding claim, wherein the second duct section is provided at a leading edge of the first duct section.

11. 11. The ductwork of any preceding claim, wherein the protrusions of the vortex generating surface protrude in a direction substantially opposite to the first direction.

12. 12. The ductwork of claim 1, wherein the first duct section interacts with the liquid flow to induce a first set of liquid properties, and the vortex generating surface interacts with the liquid flow to induce a second set of liquid properties, the second set of liquid properties including an increase in the magnitude of vorticity in the liquid flow.

13. The ductwork according to any one of claims 1 to 12, wherein the vortex generating surface is configured to induce a plurality of spatially separated vortices, e.g. periodic vortices, in the liquid flow.

14. A marine vessel comprising a duct installation according to any one of claims 1 to 13.

15. 1. A method for affecting a liquid flow, comprising: generating vortices in the liquid flow using a second duct section comprising a vortex generating surface; receiving the liquid stream in a first duct section; A rotor is housed in one of the duct sections.

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