Aircraft with flow guiding structure and flow guiding system

Abstract

An aircraft including a flow guide structure and a flow guide system are provided. The aircraft has an airflow generator and a duct extending from the airflow generator to an outlet through which airflow generated by the airflow generator is discharged. A flow directing structure is positioned toward the outlet and has a set of flow directing surfaces defining a plurality of channels. At least some of the flow guide surfaces deflect at least some of the airflow from a first direction in which the airflow travels directly upstream of the flow guide structure toward a second direction orthogonal to the first direction. The flow directing structures are reorientable such that at least some of the flow directing surfaces deflect at least some of the airflow toward a third direction orthogonal to the first direction.

Description

Technical Field

[0001] The present invention relates to the field of aircraft, and more particularly to a flow guiding structure and an aircraft having the flow guiding structure. Background Art

[0002] Aircraft designed to take off, hover, and land vertically, or nearly vertically, have inspired generations of aerospace designers since the maiden flight of Sikorsky's first helicopter in September 1939. Traditionally, these designs have been limited to helicopter-like configurations with a single, or in some cases, two, large rotors. However, systematic improvements in lightweight aerospace materials, battery and electric motor technology, and ducted fans are gradually making new vertical takeoff and landing ("VTOL") or short takeoff and landing ("STOL") designs a reality.

[0003] Modern VTOL or STOL designs typically employ this new type of distributed thrust scheme, in which lift fans are positioned in desired locations around or within the aircraft, and are driven by electric motors connected to a high-density energy source. These fans are typically oriented so that their thrust vectors are vertically downward or substantially vertically downward, with upward thrust sometimes used in certain airfoil applications, and function by drawing air through an inlet and then pushing the air mass with the fan or propeller. The reaction force, in turn, generates a thrust vector to lift the aircraft vertically off the ground, suppress downward velocity, or generate an aerodynamic balancing force. When the aircraft reaches the desired altitude, the aircraft can use one or more power systems to generate forward thrust to begin horizontal movement.

[0004] One such approach that has been explored is to place a lift fan within the airfoil, canard, or fuselage of a VTOL or STOL aircraft. This approach has been explored by many leading aerospace organizations since the early 1960s. However, this configuration has historically faced significant challenges. When high-power fans are embedded and operated within the airfoil (e.g., wings, canards, and tail) and / or fuselage of an aircraft, a number of aerodynamic and structural problems arise. These include airflow disturbances at the fan inlet that reduce efficiency, complex pitching moments generated during the transition to and from forward flight, high drag in forward flight due to interference with open duct freestream airflow, reduced fan thrust near the ground, and other structural issues associated with the lift fan and its supporting structure.

[0005] Thanks to recent advances in battery, electronic control, and stabilization technologies, the popularity of vertical take-off and landing (VTOL) flying machines is rapidly increasing. A variety of designs are being proposed, each attempting to carve out a niche in the booming market. Each of these new designs offers certain advantages over its competitors. However, each new and unique VTOL design presented presents its own set of technical challenges.

[0006] Unlike conventional aircraft designs, this new type of VTOL aircraft must operate in a completely different flight regime from standard aircraft, namely at extremely low speeds and in hover mode.

[0007] Conventional aircraft control surfaces work well at high speeds but fail at low speeds, so new methods of stability and control are needed when aircraft fly at very low speeds and close to the ground. Summary of the Invention

[0008] In a first aspect of the present disclosure, an aircraft is provided, which includes: an airflow generator; a duct extending from the airflow generator to an outlet through which the airflow generated by the airflow generator is discharged; and a flow guiding structure positioned toward the outlet, the flow guiding structure having a set of flow guiding surfaces defining a plurality of channels, at least some of the flow guiding surfaces deflecting at least some of the airflow from a first direction toward a second direction orthogonal to the first direction, in which the airflow travels just upstream of the flow guiding structure in the first direction, and the flow guiding structure being reorientable so that at least some of the flow guiding surfaces deflect at least some of the airflow toward a third direction orthogonal to the first direction.

[0009] In some or all embodiments of the first aspect, the flow directing structure is rotatable about an axis of rotation to reorient the flow directing structure.

[0010] In some or all embodiments of the first aspect, the flow directing structure is disc-shaped.

[0011] In some or all embodiments of the first aspect, the flow directing structure has teeth along its circumferential surface, the flow directing system further comprising: a pinion positioned to engage the teeth of the flow directing structure to rotate the flow directing structure about the rotational axis.

[0012] In some or all embodiments of the first aspect, the flow directing structure is rotatable through 360 degrees.

[0013] In some or all embodiments of the first aspect, channels closer to the axis of rotation are smaller than channels further from the axis of rotation.

[0014] In some or all embodiments of the first aspect, at least some of the flow directing surfaces are all of the flow directing surfaces.

[0015] In some or all embodiments of the first aspect, the channel is hexagonal in shape.

[0016] In some or all embodiments of the first aspect, the outlet is located along an airfoil of the aircraft.

[0017] In some or all embodiments of the first aspect, the airfoil is one of a wing, a canard, or a tail.

[0018] In some or all embodiments of the first aspect, the aircraft has a first wing and a second wing, each of the first wing and the second wing having the airflow generator, the duct, and the flow directing structure.

[0019] In some or all embodiments of the first aspect, the airflow generator is a fan having a fan rotation axis, wherein the flow directing structure is located adjacent to the fan, and the rotation axis of the flow directing structure is substantially parallel to the fan rotation axis.

[0020] In some or all embodiments of the first aspect, the flow guiding structure is a first flow guiding structure located in a first wing of the aircraft, a second wing of the aircraft has a second flow guiding structure, and the rotation axis of the flow guiding structure in the first wing is substantially parallel to the rotation axis of the flow guiding structure in the second wing.

[0021] In some or all embodiments of the first aspect, the flow directing structure is located in a wing of the aircraft, and the axis of rotation of the flow directing structure is substantially perpendicular to a main plane of the wing.

[0022] In a second aspect of the present disclosure, a flow guiding system is provided, which includes: a flow guiding structure, which is capable of being positioned toward an outlet of a flow of fluid, the flow of fluid traveling upstream of the flow guiding structure in a first direction, the flow guiding structure having a set of flow guiding surfaces defining a plurality of channels, at least some of the flow guiding surfaces deflecting at least some of the flow of fluid from the first direction toward a second direction orthogonal to the first direction, in which the fluid travels directly upstream of the flow guiding structure in the first direction, the flow guiding structure being capable of being reoriented so that at least some of the flow guiding surfaces deflect at least some of the fluid toward a third direction orthogonal to the first direction.

[0023] In some or all embodiments of the second aspect, the flow directing structure is rotatable about an axis of rotation to reorient the flow directing structure.

[0024] In some or all embodiments of the second aspect, the flow directing structure is disc-shaped.

[0025] In some or all embodiments of the second aspect, the flow directing structure has teeth along its circumferential surface, the flow directing system further comprising a pinion gear positioned to mesh with the teeth of the flow directing structure to rotate the flow directing structure about the rotational axis.

[0026] In some or all embodiments of the second aspect, the flow directing structure is rotatable through 360 degrees.

[0027] In some or all embodiments of the second aspect, channels closer to the axis of rotation are smaller than channels further from the axis of rotation.

[0028] In some or all embodiments of the second aspect, at least some of the flow directing surfaces are all of the flow directing surfaces.

[0029] In some or all embodiments of the second aspect, the channel is hexagonal in shape.

[0030] In some or all embodiments of the second aspect, the outlet is located along an airfoil of the aircraft.

[0031] In some or all embodiments of the second aspect, the airfoil is one of a wing, a canard, or a tail.

[0032] In some or all embodiments of the second aspect, the airflow generator is a fan having a fan rotation axis, wherein the flow directing structure is located adjacent to the fan, and the rotation axis of the flow directing structure is substantially parallel to the fan rotation axis.

[0033] In some or all embodiments of the second aspect, the channel is hexagonal in shape.

[0034] Other technical advantages may be readily understood by those skilled in the art by reviewing the following drawings and descriptions. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] For a better understanding of the embodiments described herein, and to more clearly illustrate the manner in which these embodiments are implemented, reference will now be made to the accompanying drawings, which are described by way of example only.

[0036] Figure 1A is a front, top, left side isometric view of a VTOL aircraft having a set of vertical thrust fans positioned in its wings according to an embodiment of the present disclosure.

[0037] Figure 1B yes Figure 1A An isometric view of the front, bottom, left side of a VTOL aircraft showing the flow guide disk located near the vertical thrust fan.

[0038] Figure 2 yes Figure 1A and Figure 1B Top isometric view of the flow guide disc shown in .

[0039] Figure 3 yes Figure 1A and Figure 1B A top, front, and side cutaway view of a VTOL aircraft wing showing the flow directing structure located near the vertical thrust fan.

[0040] Figure 4 Shown along Figure 2 A side cross-sectional view of the flow guiding structure taken at section 4-4.

[0041] Figure 5 Shown Figure 1A and Figure 1B A VTOL aircraft having a set of control devices and a control unit for achieving reorientation of the flow guide disk.

[0042] Figure 6A is a schematic diagram showing an aircraft with two flow guide disks in each wing oriented for stable hovering.

[0043] Figure 6B Shown Figure 6A An aircraft wherein the flow guide disk is oriented for yaw control.

[0044] Figure 6C Shown Figure 6A A vehicle in which the flow guidance disk is Figure 6B Orientation is performed with a small degree of yaw control as shown.

[0045] Figure 6D Shown Figure 6A An aircraft in which the flow guide disk is oriented to maintain a headwind and / or to accelerate forward.

[0046] Figure 6E Shown Figure 6A An aircraft wherein the flow guide disk is oriented to accommodate a crosswind.

[0047] Figure 7A is a bottom view of a VTOL aircraft according to another embodiment of the present disclosure, the aircraft having a centrally located vertical thrust fan and a flow directing structure positioned adjacent to the vertical thrust fan.

[0048] Figure 7B is a bottom view schematically illustrating a VTOL aircraft having a vertical thrust fan in each of a wing, a canard, and a horizontal stabilizer and a flow guiding disk positioned adjacent to the vertical thrust fan according to yet another embodiment of the present disclosure.

[0049] Certain examples are shown in the accompanying drawings and described in detail below. When describing these examples, the same or similar reference numerals are used to identify the same or similar elements. The drawings are not necessarily drawn to scale, and certain features or certain views in the drawings may be shown exaggerated or in schematic form for the sake of clarity and / or brevity. In addition, several examples are described in this specification. Any feature in any example may be used in conjunction with, substituted for, or otherwise combined with other features in other examples. DETAILED DESCRIPTION

[0050] For the purpose of brevity and clarity, reference numerals may be reused in the accompanying drawings to indicate corresponding or similar elements, where appropriate. In addition, in order to provide a comprehensive understanding of one or more embodiments described herein, a large number of specific details have been set forth. However, it will be understood by those skilled in the art that the embodiments described herein may be practiced without these specific details. In other cases, to avoid blurring the embodiments described herein, well-known methods, procedures, and components are not described in detail. It will first be understood that, although exemplary embodiments are shown in the drawings and described below, the principles of the present disclosure may be implemented using any number of technologies, whether or not the technology is currently known. The present disclosure should in no way be limited to the exemplary implementations and technologies shown in the drawings and described below.

[0051] Unless the context indicates otherwise, the various terms used in this specification are to be interpreted and understood in the following manner: "or" is used throughout in an inclusive sense, equivalent to "and / or"; articles and pronouns in the singular include their plural forms when used throughout, and vice versa; similarly, gendered pronouns include their corresponding pronouns, and thus the pronouns should not be understood as limiting anything described herein to use, implementation, execution, etc. by a single gender; "exemplary" is to be understood as "illustrative" or "illustrative," and does not necessarily mean "preferred" over other embodiments. Terms may be further defined herein; such definitions may apply to prior and subsequent instances of the term, as can be understood from a reading of this specification. It should also be noted that the use of the term "a" in all cases should be understood to mean "at least one," unless expressly stated otherwise or unless it is obvious that it must be understood to mean "one."

[0052] The systems, devices, and methods described herein may be modified, added to, or omitted without exceeding the scope of this disclosure. For example, the components of the systems and devices may be integrated or separated. In addition, the operations of the systems and devices disclosed herein may be performed by more, fewer, or other components, and the methods described may include more, fewer, or other steps. In addition, the steps may be performed in any appropriate order. As used herein, "each" refers to each member in a set or each member in a subset of a set.

[0053] The following description of a mobile flying device having a flow guiding structure and the embodiments described therein are provided by way of one or more examples illustrating specific embodiments of the principles, aspects, or features of the present invention. These examples are provided to illustrate, not to limit, these principles and inventions. In the description, similar components are identified throughout the specification and drawings using the same corresponding reference numerals.

[0054] The terms used in this specification are understood to have the customary and ordinary meanings as understood by persons of ordinary skill in the North American aerospace industry. Applicant expressly excludes all interpretations that are inconsistent with this specification and, in particular, expressly excludes any interpretations of the language used in the claims or this specification that would be interpreted by, for example, the United States Patent and Trademark Office (USPTO) or any other patent office, unless such interpretation is clearly supported by this specification or by objective evidence of the record (e.g., prior publications by individuals not employed by the USPTO or any other patent office) demonstrating how those skilled in the art use and understand such terms, or by expert evidence from a person with at least ten years of experience in the North American aerospace industry or its equivalent.

[0055] In terms of general orientation and direction nomenclature, for the aircraft described herein, the longitudinal direction or length direction is defined as being consistent with the fore-aft direction of flight of the aircraft in forward, straight and level flight. In the case of a fixed-wing aircraft, the longitudinal direction is parallel to the rolling direction of the wheeled landing gear. The forward direction or leading edge is toward the direction of forward travel; the rearward direction or trailing edge is away from the direction of normal forward travel of the aircraft in forward flight (i.e., rearward relative to that direction). Unless otherwise specified, vertical or up and down are used with reference to the landing terrain. Unless otherwise specified, "vertical" or "vertically" is intended to also include "substantially vertical" and "substantially vertically". Throughout the context of the aircraft, the terms "across", "lateral", "spanwise", or "laterally outboard", or "lateral" or "laterally outboard" refer to distances or orientations that are perpendicular or substantially perpendicular relative to the longitudinal centerline of the fuselage. The commonly used engineering terms "protruding," "flush," and "indented" may be used herein to refer to elements that protrude beyond, are flush with, or do not extend as far as adjacent elements, respectively, and these terms conceptually correspond to the conditions of "greater than," "equal to," and "less than."

[0056] These directions generally correspond to a Cartesian coordinate system with the x-direction being longitudinal, the y-direction being lateral, and the z-direction being vertical. Pitch motion is the angular motion of the aircraft about a horizontal axis that is perpendicular to the longitudinal direction. Yaw is the angular motion about a vertical axis. Roll is the angular motion about a longitudinal axis. Given that the aircraft described herein may be intended to have a longitudinal axis of symmetry, a description of one half of the aircraft is generally intended to describe the other half as well, allowing for differences in left and right side components. Furthermore, unless otherwise shown in the drawings or otherwise noted in the text, it is assumed that the basic structure of the aircraft is an aluminum structure with reinforced composite surface skins. Other materials such as stainless steel or wood may also be used for certain components.

[0057] For the purposes of this discussion, it is understood that a person of ordinary skill is familiar with aircraft construction and maintenance in North America and may include an aircraft maintenance engineer who possesses knowledge of the U.S. Department of Transportation's Federal Aviation Administration publications EA-AC 43.13-1A and 2A, "Acceptable Methods, Techniques and Practices, Aircraft Inspection and Repair," or its successor publications (e.g., as updated as of the priority date of this specification). This specification should be interpreted consistently with such publications.

[0058] Figure 1A and Figure 1BAn aircraft 20 according to one embodiment is shown. The aircraft 20 is a VTOL or STOL aircraft, i.e., it is capable of taking off and landing vertically, substantially vertically, or using a short horizontal runway. Although the principles, aspects, and features of the invention herein may be applied to other VTOL or STOL aircraft, such as configurations in which a plurality of vertical or substantially vertically propelled fans are positioned in the airfoil, it is contemplated that the invention may be applied to a VTOL or STOL aircraft. Figure 1A and Figure 1B In the illustrated embodiment, aircraft 20 utilizes a high-wing VTOL configuration, wherein the airfoil is optimized for efficient forward flight. Aircraft 20 includes a fuselage 24 and two airfoils in the form of wings 28 extending from fuselage 24. A tail structure connected to fuselage 24 includes a pair of vertical stabilizers 32. Aircraft 20 can generate forward thrust via any known means, such as propellers and turbines mounted on the fuselage, wings, or tail structure.

[0059] For takeoff and / or landing, the aircraft 20 includes a thrust system that generates downward airflow. Specifically, each wing 28 has a pair of vertical thrust fans 36 positioned along the span of the wing 28. The vertical thrust fans 36 are driven to rotate to generate vertical thrust, thereby providing vertical thrust for the aircraft 20, typically during takeoff and landing. The wings 28 can be forward-swept, backward-swept, neutrally swept, or any other suitable shape. Each vertical thrust fan 36 is located in a duct 40 within the corresponding wing 28 to guide the airflow generated by the vertical thrust fan 36. Each duct 40 extends from the vertical thrust fan 36 to an outlet 44 through which the airflow generated by the vertical thrust fan 36 is discharged. In this embodiment, the vertical thrust fans 36 are electric turbines, but any other suitable method can also be used to generate airflow discharged through an outlet positioned along the lower surface of the aircraft.

[0060] Downstream of each vertical thrust fan 36 and adjacent to each vertical thrust fan 36 and toward the outlet 44, a flow guiding structure in the form of a flow guide disc 48 is positioned. The flow guide disc 48 is a relatively thin flow guiding plate, whose diameter, in some embodiments, is at least eight times its thickness. It deflects at least part of the airflow from a first direction in which the airflow travels upstream of the flow guide disc 48 (the original outflow axis) to a second direction that is inclined relative to the first direction, thereby causing an overall change in direction of the exhaust gas and thus generating an off-axis vector. In this embodiment, the airflow generated by the vertical thrust fan 36 travels parallel to the axis of rotation of the vertical thrust fan 36 before reaching the flow guide disc 48. However, in other embodiments, the airflow generators can be positioned further away from the outlet and offset so that they are no longer directly above the flow guiding structure. In addition, the flow guide disc 48 reduces the rotational component of the existing airflow outflow and redirects it in a modified and controlled direction.

[0061] Along each wing 28, a first flow guiding disk 48a is located towards the root 49 of the wing 28 and a second flow guiding disk 48b is located towards the tip 50 of the wing 28. The flow guiding disks 48a, 48b will hereinafter be referred to collectively or alternatively as flow guiding disks 48.

[0062] Now refer to Figures 2 to 4 , shows that the flow guide disk 48 is generally circular and has an annular coupling ring 52. The annular coupling ring 52 provides support for three bearing supports 54. Each bearing support 54 supports a freely rotating annular bearing 56, which is received in an internal groove 57 within a vertical thrust fan support 58, which rotatably supports a hub 59 of a corresponding vertical thrust fan 36. Alternatively, in other configurations, the bearings of the flow guide disk can be located toward its peripheral edge.

[0063] The inner peripheral wall 60 and the outer peripheral wall 64 enclose a channel-defining (in this case, honeycomb-like) structure 68. The channel-defining structure 68 includes a plurality of thin walls connected together to define a channel 72 that extends generally through the flow directing disk 48. A toothed peripheral surface 76 having a set of teeth 80 extends circumferentially around the outside of the outer peripheral wall 64.

[0064] A pinion gear 84 is positioned within the airfoil 28 to mesh with the toothed peripheral surface 76. A pinion shaft motor 88 drives a pinion shaft coupled to the pinion gear 84 to rotate. The pinion shaft motor 88 drives the pinion gear 84, causing the flow guide disk 48 to rotate about a rotation axis RA shared with the vertical thrust fan 36. The flow guide disk 48 does not have a limited range of rotation and is capable of a full 360-degree rotation. In other embodiments, the rotation range of the flow guide disk may be limited.

[0065] The flow guiding disk 48 is positioned within the duct 40 adjacent to the vertical thrust fan 36, directing the airflow generated by the vertical thrust fan 36 through the passage-defining structure 68. The passage-defining structure 68 has thin walls 92 that define the passage 72 through the flow guiding disk 48 and form the majority of the flow guiding disk 48. The thin walls 92 of the passage-defining structure 68 reduce resistance to the airflow. The walls 92 are tilted by θ degrees relative to the rotational angle RA of the flow guiding disk 48. Consequently, the flow guiding surface 96 of the wall 92 deflects the airflow in a direction DD that is different from the direction of airflow traveling upstream of the flow guiding disk 48; that is, generally parallel to the rotational axis RA of the flow guiding disk 48. In this embodiment, the cell array of the passage-defining structure 68 utilizes a straight-sided hexagonal shape to increase rigidity and reduce the overall material used in the flow guiding disk 48, thereby reducing its weight. The upstream inlet face of the flow guiding disk 48 has a specific cell pattern. The turning outlet face of the flow guiding disk 48 has a similar, matching cell pattern. The outlet pattern is skewed (translated and / or rotated) relative to the inlet face. The inlet and outlet patterns are joined by lofted walls 92 to produce the desired unit cell shape for the channel 72. The dimensions of each flow cell are optimized for the desired deflection and directed outflow velocity.

[0066] Rotation of the flow guiding disk 48 about the upstream flow axis causes the exhaust flow to be redirected as an inclined flow about the axis of rotation RA of the flow guiding disk 48. The inclined exhaust flow thus contains a vertical component and a horizontal component relative to the axis of rotation RA of the flow guiding disk 48. The vertical component of the exhaust flow provides lift to the aircraft, while the horizontal component can be used to cause the aircraft to undergo rotational and translational motion parallel to the ground surface.

[0067] The airflow generated toward the tips of the fan blades of the vertical thrust fan 36 increases as the distance from the axis of rotation of the vertical thrust fan 36 increases. The flow guide disk 48 can be designed to compensate for the increased radial airflow. For example, the wall 92 of the passage-defining structure 68 can be inclined less as the distance from the axis of rotation RA decreases, as the amount of deflection required toward the periphery of the flow guide disk 48 decreases, thereby providing a more uniform lateral thrust on the flow guide disk 48. In another embodiment, the size of the passage 72 of the flow guide disk 48 can be increased, thereby further spacing the flow guide surfaces 96 toward the periphery of the flow guide disk 48, thereby reducing the horizontal thrust generated toward the periphery of the flow guide disk 48.

[0068] exist Figures 2 to 4 In the illustrated embodiment, although the cross-section of the channel 72 defined by the channel-defining structure 68 is hexagonal, in other embodiments, the cross-section of the channel provided by the channel-defining structure 68 may have other shapes.

[0069] The skewed extruded cell shape of the channels 72 described above has two main effects on the fan outflow. First, the cells tend to linearize any remaining rotational or spiral motion in the outflow. This creates a torque on the flow guide disk 48. Second, the entire outflow is slightly bent in one direction. This creates a lateral force on the flow guide disk 48, the direction of which depends on the angle of rotation of the flow guide disk 72. Because the rotation of the flow guide disk 72 can be controlled, the resulting lateral force can be directed in any desired horizontal direction. For example, a 16-degree skew translation between the inlet and outlet cell patterns will deflect the main outflow flow away from the axial direction by approximately 14 degrees; that is, parallel to the rotational axis RA of the flow guide disk 48. This slightly reduces the vertical force to 94% of the original force. However, 22% of the vertical force is now available and applied in the radial direction.

[0070] During vertical takeoff and landing, the vertical thrust fan 36 is used to provide vertical thrust. When the aircraft completes vertical takeoff and generates forward thrust via some type of forward propulsion system, such as one or more propellers, jet engines, etc., the vertical thrust fan 36 can be decelerated and eventually turned off. During this phase of flight, the flow guide disc 48 is no longer reoriented. In some configurations, when the vertical thrust fan 36 is powered off, the flow guide disc can be restored to its original position. Figure 7A This means that once the vertical thrust fans 36 begin operating, the flow guide disks 48 will not cause the aircraft to yaw.

[0071] The flow guiding disk 48 b , located toward the tip 50 of the wing 28 , operates to produce a net torque force vector about the vertical axis (yaw axis) of the aircraft 20 .

[0072] By controlled and selective rotation of each flow guiding disk 48, a combination of horizontal force vectors can be used to position the aircraft 20. During flow guiding disk rotation, the net vertical lift on each vertical thrust fan 36 remains constant, achieving zero cross-coupling of lift / side force.

[0073] Now refer to Figure 5Aircraft 20 has a set of controls 97 for controlling the operation of the aircraft. Controls 97 include a joystick, sidestick, or centerstick, throttle, and rudder pedals. Using controls 97, the pilot can perform maneuvers such as vertical takeoff or landing, yaw, and so on. As will be appreciated, rudder pedals are conventionally used to control the yaw of aircraft 20. When it is necessary to yaw aircraft 20 during normal forward flight, the rudder pedals pivot the rudder in the tail of aircraft 20. When aircraft 20 is propelled forward, the rudder is subjected to air forces in its non-neutral position, causing the tail of aircraft 20 to move to the right or left. When aircraft 20 is not moving forward at a sufficient speed to generate sufficient force to propel the tail sideways, such as when the aircraft is taking off or landing vertically, or substantially vertically, it may be desirable to provide yaw control in other ways. For example, the rudder pedals may be connected to the control unit 98, which rotates the flow guide disks 48 based on the position of the rudder pedals to generate a twisting force on the aircraft 20, thereby rotating the aircraft 20. The control unit 98 may be preconfigured to rotate the flow guide disks 48 based on some relationship between the rudder pedal position, the speed of the vertical thrust fans 36, etc. In other embodiments, other control devices may be used to control the rotation of the flow guide disks 48.

[0074] Figure 6A An exemplary aircraft 200 is shown having two vertical thrust fans and flow guide disks 204a, 204b in each of its two wings 208. The first vertical thrust fan and first flow guide disk 204a in each wing are positioned toward the root 212 of the wing 208, while the second vertical thrust fan and second flow guide disk 204b are positioned toward the tip 216 of the wing 208. During normal operation, all flow guide disks 204 are oriented to direct airflow away from the fuselage 220, as indicated by the arrows shown atop the flow guide structures 204. The net rotational or yawing force is zero. Although not shown, the aircraft 200 also includes a horizontal thrust device for generating forward thrust. The horizontal thrust device can be any suitable device for generating forward thrust, such as one or more propellers, one or more jet engines, etc.

[0075] During takeoff, to reduce the risk of foreign matter being ingested by the vertical thrust fans and to improve cockpit visibility, it is desirable to blow any loose material away from the fuselage. This is achieved by directing a portion of the airflow from the vertical thrust fans laterally away from the aircraft 200. Furthermore, when using a fuselage-mounted crane to lift personnel or cargo, this configuration can direct the airflow away from the fuselage 220. This reduces turbulence in the sling load.

[0076] Figure 6BThe orientation of the flow guide disk 204 is shown when it is desired to yaw the aircraft 200 to the left. Figure 6A The neutral position shown is towards Figure 6B When the position shown is rotated, the aircraft 200 begins to yaw to the left. This configuration is used to point the nose of the aircraft 200 in a desired direction when there is no wind and the aircraft is hovering. Figure 6C The orientation of the flow guide disks 204 is shown when less yaw is required. Specifically, the second flow guide disk 204b in each wing 208 is oriented to provide a twisting force to the vehicle 200, while the first flow guide disk 204a is oriented for general hovering and does not participate in the yaw provided by the second flow guide disk 204b. This yaw configuration can be helpful when taxiing in tight spaces—the wheel brakes are close to the centerline, so a significant amount of thrust is required to turn the vehicle 200 when moving at slow speeds on the ground.

[0077] Figure 6D The orientation of the flow guide disks 204 for forward flight and / or counteracting headwinds is shown. All four flow guide disks 204a, 204b are shown oriented to direct a portion of the airflow from the vertical thrust fans rearwardly.

[0078] Figure 6E The orientation of the flow guide disk 204 when used to counteract a crosswind or to translate the aircraft 200 laterally is shown.

[0079] It is important to understand that although Figures 6A to 6E In the above embodiment, the flow guide plates 204 are oriented in a specific orientation, but other combinations of orientations can also achieve similar results. In addition, the flow guide plates 204a and 204b can provide different levels of lateral redirection of the airflow generated by the vertical thrust fan by using different channel-defining structures.

[0080] Figure 7A An aircraft 300 according to another embodiment is shown, wherein a vertical thrust fan and a flow guide disk 304 are located approximately in the center of the aircraft. The flow guide disk 304 is configured to translate the aircraft horizontally sideways, forward, and backward, and to stabilize the aircraft 300 horizontally. Although not shown, the aircraft 300 also includes a horizontal thrust device for generating forward thrust. The horizontal thrust device can be any suitable device for generating forward thrust, such as one or more propellers, one or more jet engines, etc.

[0081] Figure 7BAn aircraft 400 is shown having a set of airfoils, namely a pair of wings 404, a pair of canards 408, and two horizontal stabilizers 412, which form part of the tail of the aircraft 400. Each of the wings 404, canards 408, and horizontal stabilizer 412 has a vertical thrust fan and a flow guide disk 416 positioned therein. Although not shown, the aircraft 40 also includes a horizontal thrust device for generating forward thrust. The horizontal thrust device can be any suitable device for generating forward thrust, such as one or more propellers, one or more jet engines, etc.

[0082] The flow guide disks 406 can be operated to similarly control yaw or translational motion. However, to control yaw, the flow guide disks 416 in the canards 408 or the empennage 412 must act in concert (i.e., redirecting a portion of the airflow toward one lateral side of the aircraft), while the flow guide disks 416 in the main wing 404, because of their proximity to the center of gravity, must operate in opposition to each other to achieve yaw.

[0083] Additionally, the canard and tail deflector plates will need some degree of coordination between them (i.e. canards to back to tail to contribute clockwise or counterclockwise rotational torque evenly)

[0084] It is contemplated that during forward flight, the inlet and outlet of the vertical takeoff fan may be covered, such as via sliding covers.

[0085] Although the flow directing structure is disc-shaped in the embodiments described and shown above, in other embodiments, the flow directing structure may take other forms.

[0086] In certain embodiments, some or all of the flow directing structures may have their orientation fixed, or operate independently of other flow directing structures.

[0087] It will also be readily understood by those skilled in the art that the airfoil design may be used for both manned and unmanned aerial vehicles, such as reconnaissance aircraft.

[0088] The airfoil designs disclosed herein may also be used for hydrofoils of surface vessels or any other craft that moves through a fluid. It should be understood that the configuration of the hydrofoil may be adjusted to prevent water ingress to certain components.

[0089] The principles of the present invention described and illustrated with respect to an aircraft wing may also be applied to other airfoils of an aircraft, such as canards and tailplanes.

[0090] It will be appreciated that various aspects and features may be mixed and matched as desired. It will also be appreciated that the foregoing is not intended to be an exhaustive list of aspects and features of the present invention. These and other aspects and features of the present invention may be understood by reference to the foregoing description and in conjunction with the diagrams provided.

[0091] Various embodiments have been described in detail. Since changes and / or additions may be made to the above examples without departing from the nature, spirit or scope of the invention, the invention should not be limited to these details.

[0092] While specific advantages have been enumerated above, various embodiments may include some, all, or none of the enumerated advantages.

[0093] Those skilled in the art will appreciate that there are other possible alternative implementations and modifications, and the above examples are only examples of one or more implementations. Therefore, the scope of the present invention is limited only by the appended claims and any amendments thereto.

Claims

1. An aircraft, comprising: airflow generator; a duct extending from the airflow generator to an outlet through which the airflow generated by the airflow generator is discharged; as well as a flow directing structure positioned toward the outlet, the flow directing structure having a set of flow directing surfaces defining a plurality of channels, at least some of the flow directing surfaces deflecting at least some of the airflow from a first direction toward a second direction orthogonal to the first direction, in which the airflow travels directly upstream of the flow directing structure, the flow directing structure being reorientable such that at least some of the flow directing surfaces deflect at least some of the airflow toward a third direction orthogonal to the first direction.

2. The aircraft according to claim 1, wherein: The flow directing structure is rotatable about an axis of rotation to reorient the flow directing structure.

3. The aircraft according to claim 2, wherein: The flow guiding structure is disc-shaped.

4. The aircraft according to claim 3, wherein: The flow guiding structure has teeth along its circumferential surface, the flow guiding system further comprising: A pinion gear is positioned to mesh with the teeth of the flow directing structure to rotate the flow directing structure about the axis of rotation.

5. The aircraft according to claim 4, wherein: The flow directing structure is rotatable through 360 degrees.

6. The aircraft according to any one of claims 2 to 5, wherein: Channels closer to the axis of rotation are smaller than channels further from the axis of rotation.

7. The aircraft according to any one of claims 1 to 6, wherein: At least some of the flow directing surfaces are all of the flow directing surfaces.

8. The aircraft according to any one of claims 1 to 7, wherein: The channel is hexagonal in shape.

9. The aircraft according to any one of claims 1 to 8, wherein: The outlet is located along an airfoil of the aircraft.

10. The aircraft according to claim 9, wherein: The airfoil is one of a wing, a canard or a tail.

11. The aircraft according to claim 9, wherein: The aircraft has a first wing and a second wing, each of the first wing and the second wing having the airflow generator, the duct, and the flow directing structure.

12. An aircraft according to any one of claims 3 to 5, wherein: The airflow generator is a fan having a fan rotation axis, wherein the flow directing structure is located adjacent to the fan, and wherein the rotation axis of the flow directing structure is substantially parallel to the fan rotation axis.

13. The aircraft according to claim 12, wherein: The flow guiding structure is a first flow guiding structure located in a first wing of the aircraft, wherein a second wing of the aircraft has a second flow guiding structure, and wherein an axis of rotation of the flow guiding structure in the first wing is substantially parallel to an axis of rotation of the flow guiding structure in the second wing.

14. The aircraft according to claim 12, wherein: The flow guiding structure is located in a wing of the aircraft, and wherein the axis of rotation of the flow guiding structure is substantially perpendicular to a main plane of the wing.

15. A flow guiding system, comprising: A flow directing structure capable of being positioned toward an outlet of a flow of fluid, the flow of fluid traveling upstream of the flow directing structure in a first direction, the flow directing structure having a set of flow directing surfaces defining a plurality of channels, at least some of the flow directing surfaces deflecting at least some of the flow of fluid from the first direction toward a second direction orthogonal to the first direction, in which the fluid travels directly upstream of the flow directing structure, the flow directing structure capable of being reoriented so that at least some of the flow directing surfaces deflect at least some of the fluid toward a third direction orthogonal to the first direction.

16. The flow guiding system according to claim 15, wherein: The flow directing structure is rotatable about an axis of rotation to reorient the flow directing structure.

17. The flow guiding system according to claim 16, wherein: The flow guiding structure is disc-shaped.

18. The flow guiding system according to claim 17, wherein: The flow guiding structure has teeth along its circumferential surface, the flow guiding system further comprising: A pinion gear is positioned to mesh with the teeth of the flow directing structure to rotate the flow directing structure about the axis of rotation.

19. The flow guiding system of claim 18, wherein: The flow directing structure is rotatable through 360 degrees.

20. A flow guiding system according to any one of claims 15 to 19, wherein: Channels closer to the axis of rotation are smaller than channels further from the axis of rotation.

21. A flow guiding system according to any one of claims 15 to 20, wherein: The channel is hexagonal in shape.

22. A flow guiding system according to any one of claims 15 to 21, wherein: At least some of the flow directing surfaces are all of the flow directing surfaces.

23. A flow guiding system according to any one of claims 15 to 22, wherein: The channel is hexagonal in shape.

24. A flow guiding system according to any one of claims 15 to 23, wherein: The outlet is located along an airfoil of the aircraft.

25. The flow directing system of claim 24, wherein: The airfoil is one of a wing, a canard or a tail.

26. A flow guiding system according to any one of claims 17 to 20, wherein: The airflow generator is a fan having a fan rotation axis, wherein the flow directing structure is located adjacent to the fan, and wherein the rotation axis of the flow directing structure is substantially parallel to the fan rotation axis.

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