Aerodynamic layout of three-wing aircraft

Abstract

An embodiment of the present invention discloses an aerodynamic layout of a three-wing aircraft, comprising: a fuselage, the fuselage having a head and a tail that are separated from each other; a canard and a wing, the canard and the wing being fixedly connected to the fuselage in sequence along a direction from front to back; a tail strut, the tail strut being fixedly connected to the wing or the fuselage and extending backward; a vertical tail, the vertical tail being fixedly connected to the end of the tail strut; and a horizontal tail, the horizontal tail being fixedly connected to the tail strut or the vertical tail; wherein at least two first propulsion units are fixedly mounted on the wing; and a second propulsion unit is fixedly mounted on the tail. According to the present invention, it adopts a multi-engine low-power propulsion device in conjunction with a single-engine high-power auxiliary propulsion device to improve the overall efficiency of the entire flight mission, reduce energy consumption during flight, and meet the green aviation requirements of energy saving, emission reduction and noise reduction of aircraft.

Description

Technical Field

[0001] The invention relates to the field of aircraft aerodynamic layout, and in particular to an aerodynamic layout of a three-wing aircraft. Background Art

[0002] With the development of the global aviation industry, many countries and organizations are focusing on the promotion and development of low-carbon or even zero-carbon emission green aviation. ICAO, the United States and Europe have formulated a series of standards and documents to guide the aviation industry towards green and environmental protection in terms of energy saving, emission reduction and noise reduction. In the context of green environmental protection, for civil transport aircraft, the existing conventional aerodynamic layout has increasingly limited design and development potential in terms of aerodynamic efficiency. In addition, the overall efficiency of traditional turbofan engines after installation is limited by the size of the engine, which affects the aerodynamic efficiency of the aircraft during the cruise phase.

[0003] In view of this, it is very necessary to provide an aerodynamic layout of a three-wing aircraft that can meet the requirements of green aviation and have efficient aerodynamic performance, and to explore and study the aircraft body and propulsion method. Summary of the invention

[0004] An embodiment of the present invention provides an aerodynamic layout of a three-wing aircraft, which adopts a three-wing aerodynamic layout and adopts a multi-engine first propulsion unit in conjunction with a single-engine second propulsion unit to improve the overall efficiency of the entire flight mission, reduce energy consumption during the flight, and meet the green aviation requirements of aircraft energy saving, emission reduction and noise reduction.

[0005] In order to solve the above technical problems, the embodiments of the present invention disclose the following technical solutions:

[0006] An aerodynamic layout of a three-wing aircraft is provided, comprising:

[0007] a fuselage having a head portion and a tail portion facing away from each other;

[0008] A front wing and a wing, wherein the front wing and the wing are fixedly connected to the fuselage in sequence from front to back;

[0009] A tail strut, the tail strut being fixedly connected to the wing or the fuselage and extending rearward;

[0010] a vertical tail fin, the vertical tail fin being fixedly connected to a distal end of the tail strut; and

[0011] A horizontal tail wing, the horizontal tail wing being fixedly connected to the tail strut or the vertical tail wing;

[0012] Among them, at least two first propulsion units are fixedly installed on the wing; and a second propulsion unit is fixedly installed on the tail.

[0013] In addition to one or more of the features disclosed above, or as an alternative, it also includes a diagonal strut, the wing has a fixed end and a free end that are away from each other in the wingspan direction, and the wing is fixedly connected to the fuselage via the fixed end; the diagonal strut is obliquely fixedly connected between the vicinity of the fixed end and the fuselage, so that the wing, the diagonal strut and part of the fuselage are sequentially connected around each other to form a triangular support structure.

[0014] In addition to one or more features disclosed above, or as an alternative, the wing includes an inner wing and an outer wing arranged in sequence from the inside to the outside in the wingspan direction; the sweep angle of the diagonal strut is opposite to the sweep angle of the inner wing.

[0015] In addition to one or more features disclosed above, or as an alternative, when the inner wing is arranged to be swept back, the diagonal strut is arranged to be swept forward. At this time, the sweep angle of the inner wing is 0° to 40°, and the sweep angle of the diagonal strut is 0° to -40°.

[0016] In addition to one or more features disclosed above, or as an alternative, when the inner wing is arranged to be swept forward, the diagonal strut is arranged to be swept backward. At this time, the forward sweep angle of the inner wing is 0° to -40°, and the backward sweep angle of the diagonal strut is 0° to 40°.

[0017] In addition to or as an alternative to one or more of the features disclosed above, the outer wing is arranged to be swept, and the sweep angle of the outer wing is 0° to 25°.

[0018] In addition to or as an alternative to one or more of the features disclosed above, the wing is a high-wing aerodynamic layout.

[0019] In addition to or as an alternative to one or more of the features disclosed above, a wing platform is provided on the top of the fuselage, and the wing is fixedly connected to the fuselage via the wing platform.

[0020] In addition to or as an alternative to one or more of the features disclosed above, the aspect ratio of the wing is 15-25.

[0021] In addition to one or more of the features disclosed above, or as an alternative, the canard is provided with a pair, and the two canards are arranged symmetrically with respect to the fuselage; the canard is a dihedral aerodynamic layout, and the dihedral angle of the canard is 0° to 10°.

[0022] In addition to or as an alternative to one or more of the features disclosed above, the two front wings are symmetrically mounted on both sides of the head.

[0023] In addition to one or more of the features disclosed above, or as an alternative, the wing is provided with a pair, and the two wings are arranged symmetrically with respect to the fuselage; the first propulsion unit is arranged to be composed of at least one propulsion subset, each of the propulsion subsets includes a pair of the first propulsion units arranged symmetrically with respect to the fuselage, and each first propulsion unit in each of the propulsion subsets is fixedly mounted to a corresponding wing.

[0024] In addition to one or more of the features disclosed above, or as an alternative, the tail strut is provided with a pair, and the two tail struts are arranged symmetrically with respect to the fuselage; the vertical tail is provided with two pieces, each piece of the vertical tail is fixedly connected to the end of a corresponding one of the tail struts, and the horizontal tail is fixedly connected between the two pieces of the vertical tail.

[0025] In addition to or as an alternative to one or more of the features disclosed above, the installation height of the horizontal tail is higher than the installation height of the wing.

[0026] In addition to or as an alternative to one or more of the features disclosed above, the second propulsion unit is a propulsion device with a foldable propeller or a propeller fan, and the second propulsion unit includes:

[0027] an engine, the engine being mounted to the tail;

[0028] a power output shaft, the power output shaft being drivingly connected to the engine, the power output shaft extending rearwardly along the longitudinal axis of the fuselage and emerging from the engine to form a central cone;

[0029] at least two spaced-apart blades, the roots of the blades being hinged to the central cone; and

[0030] a reset component, the reset component being arranged on the central cone and acting on the blades, so that the blades rotate relative to the central cone to switch from an extended state to a retracted state;

[0031] Wherein, when the blades are in the deployed state, the blades are radially arranged on the periphery of the central cone; when the blades are in the retracted state, the blades gather to the periphery of the central cone.

[0032] In addition to or as an alternative to one or more of the features disclosed above, the first propulsion unit and / or the second propulsion unit is electrically driven.

[0033] In addition to or as an alternative to one or more features disclosed above, the first propulsion unit is used to provide thrust during the cruise phase; during the take-off, climb and landing go-around phases, the first propulsion unit and the second propulsion unit are used to jointly provide thrust.

[0034] In addition to or as an alternative to one or more of the features disclosed above, the first propulsion unit is a propulsion device with a propeller or a propeller fan, and the wing control surface of the wing is arranged behind the propeller or the propeller fan.

[0035] In addition to or as an alternative to one or more of the features disclosed above, the wing control surface includes at least one of a flap, a flaperon and an aileron.

[0036] In addition to one or more of the features disclosed above, or as an alternative, the cane also includes a cane elevator, and the horizontal tail also includes a horizontal tail elevator; the cane elevator and the horizontal tail elevator change the pitch moment of the aircraft through reverse differential upward and downward deflection to control the pitch attitude of the aircraft; the cane elevator and the horizontal tail elevator adjust the magnitude of the aircraft's level flight lift through simultaneous upward or downward deflection, thereby being able to perform altitude translation of the aircraft without changing the aircraft's attitude.

[0037] One of the above technical solutions has the following advantages or beneficial effects: because it adopts a three-wing aerodynamic layout and installs a multi-engine first propulsion unit on the wing, it cooperates with a single-engine second propulsion unit to improve the overall efficiency of the entire flight mission, reduce energy consumption during the flight, and meet the green aviation requirements of aircraft energy saving, emission reduction and noise reduction.

[0038] One of the above technical solutions has the following combination and use method: during the take-off, climb and landing go-around stages, the multi-engine first propulsion unit operates, the trailing edge flaps and ailerons are deflected downward, and under the influence of the slipstream effect, the lift of the entire aircraft is increased and the take-off and landing speeds are reduced; at the same time, the propeller or propeller fan of the second propulsion unit rotates and unfolds to provide a large additional thrust; the canard and horizontal tail are combined to perform torque balancing, pitch control or altitude fine-tuning of the entire aircraft, which improves the take-off and landing trajectory control capability of the aircraft compared to traditional aircraft, and ensures that the canard stalls first at large angles of attack to provide a nose-down torque for the entire aircraft; in the cruise stage, the trailing edge flaps and ailerons are folded, and the first propulsion unit provides stable cruising thrust. At the same time, the propeller or propeller fan of the second propulsion unit is folded into a retracted state by means of the reset component at the root hinge. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The technical solutions and other beneficial effects of the present invention will be made apparent by describing in detail the specific embodiments of the present invention in conjunction with the accompanying drawings.

[0040] Figure 1 An axonometric view of an aircraft in which an embodiment of the present invention may be implemented, showing the major components of the aircraft;

[0041] Figure 2is a top view of an aircraft that can implement an embodiment of the present invention, showing the structural state of the inner wing of the aircraft wing when it is in a swept aerodynamic layout;

[0042] Figure 3 is a top view of an aircraft that can implement an embodiment of the present invention, showing the structural state of the inner wing of the aircraft wing when it is in a forward-swept aerodynamic layout;

[0043] Figure 4 is a partial enlarged view of an aircraft that can implement an embodiment of the present invention, showing the structural details of the tail of the fuselage and the second propulsion unit, and the blades are in an unfolded state at this time;

[0044] Figure 5 This is a partial enlarged view of an aircraft that can implement an embodiment of the present invention, showing the structural details of the tail of the fuselage cooperating with the second propulsion unit, and the blades are in a retracted state at this time. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0046] Existing aircraft, such as modern civil transport aircraft, currently basically adopt a conventional aerodynamic layout with a horizontal tail. The horizontal tail generates negative lift downward for trimming. When a conventional aerodynamic layout aircraft is trimmed in flight, the horizontal tail will generate negative lift, reducing the aerodynamic characteristics of the aircraft, and at the same time, a moment pitch-up problem will occur at a large angle of attack. For a T-tail, it is also easily affected by the wing wake at a large angle of attack, so that the tail and elevator are both in the wing wake, resulting in poor pitch controllability, entering a deep stall and difficult to recover.

[0047] Furthermore, most modern civil transport aircraft generally use conventional turbofan engines with larger bypass ratios and geometric dimensions to provide power during flight, or use turboprop engines or piston engines to drive conventional larger diameter propellers / propfans to provide power during flight. The number of engines generally ranges from 1 to 4, and very few aircraft use 6, which are generally of the same model and form. Conventional power units or engines are used in all flight phases, and they pay a greater price in life, weight, and geometric dimensions for the short working time of medium and low speed high thrust conditions, resulting in more cost and consideration for the overall design of the aircraft, as well as an increase in project costs; and the number of engines is relatively small. In order to improve the economy, the only way is to increase the bypass ratio or the propeller disc area, which will lead to a further increase in the geometric dimensions of the power unit and increase the difficulty of aircraft design; relying entirely on the combustion of conventional fuels will produce more carbon emissions, making it difficult to achieve environmental protection concepts; relying entirely on lithium battery energy storage can only be applied to small UAVs or light aircraft with limited performance, and the battery weight is unacceptable when the aircraft solution is large-scaled; relying entirely on hydrogen fuel cells, the maximum required power is difficult to achieve or an excessive and unacceptable weight price is paid for the required power. At the same time, there are many difficult-to-solve problems with the storage and refueling of hydrogen or even liquid hydrogen in aircraft and airports, involving many aspects such as insufficient storage space and storage safety.

[0048] In the context of global warming, many countries and organizations have formulated "dual carbon" green environmental protection strategies such as carbon peak and carbon neutrality. In this context, many countries and organizations focus on the promotion and development of green aviation with low or even zero carbon emissions. According to a series of standards and documents formulated by ICAO, the United States and Europe, aviation is guided towards green development in terms of energy saving, emission reduction and noise reduction. As a result, for civil transport aircraft, the design potential of existing conventional layout aircraft in terms of aerodynamic efficiency is increasingly limited. Therefore, in the context of the new era's needs, it is very urgent and necessary for airlines to provide an unconventional aerodynamic layout that can meet green aviation and have efficient aerodynamic performance.

[0049] Based on the above background, the aircraft in the exemplary embodiment disclosed in this article adopts a three-wing aerodynamic layout and uses a multi-engine first propulsion unit in conjunction with a single-engine second propulsion unit to improve the overall efficiency of the entire flight mission, reduce energy consumption during the flight, and meet the green aviation requirements of aircraft energy saving, emission reduction and noise reduction.

[0050] refer to Figure 1 , Figure 1 The figure is an axonometric diagram of an aircraft that can implement the embodiment of the present invention. The figure shows the main components of the aircraft 1. The aircraft 1 includes a fuselage 10, a front wing 11, a wing 12, a vertical tail 15 and a horizontal tail 13. The body coordinate system Ox b y bz b It can be used as a reference for certain dimensional features of the aircraft 1. In the following text and throughout the specification, the term "body coordinate system" should be understood as a moving coordinate system that is fixed to the aircraft and moves with the aircraft, wherein the body coordinate system Ox b y b z b The origin O is located at the center of mass of the aircraft; the longitudinal axis Ox b In the symmetry plane of the aircraft, parallel to the fuselage axis or the average aerodynamic chord of the wing, with the forward direction as the positive direction; the horizontal axis Oy b Perpendicular to the symmetry plane, with right as positive (from the cockpit perspective); vertical axis (vertical axis) Oz b The horizontal axis is also in the symmetry plane and perpendicular to the vertical axis Ox. b , with downward being positive.

[0051] Reference Figure 1 and Figure 2 , Figure 2 The figure is a top view of an aircraft that can implement an embodiment of the present invention, showing the structural state of the inner wing of the aircraft wing when it is in a swept aerodynamic layout. Specifically, the aerodynamic layout of a three-wing aircraft 1 includes:

[0052] A fuselage 10, wherein the fuselage 10 has a head portion 101 and a tail portion 102 which are separated from each other;

[0053] A front wing 11 and a wing 12, wherein the front wing 11 and the wing 12 are fixedly connected to the fuselage 10 in sequence from front to back;

[0054] a tail strut 14, wherein the tail strut 14 is fixedly connected to the wing 12 or the fuselage 10 and extends rearward;

[0055] a vertical tail 15, wherein the vertical tail 15 is fixedly connected to the end of the tail support 14; and

[0056] A horizontal tail 13, wherein the horizontal tail 13 is fixedly connected to the tail support 14 or the vertical tail 15;

[0057] At least two first propulsion units 17 are fixedly mounted on the wing 12, and a second propulsion unit 16 is fixedly mounted on the tail 102. The main control surfaces of the three-plane aircraft 1 include a horizontal tail elevator 131, a rudder 151, an inner flap 122, an aileron 123 and an aileron 124, and a front wing elevator 111. In addition, a winglet 121 is also provided at the wing tip of the wing 12.

[0058] In the above and throughout the specification, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "at least two" means two or more, unless otherwise clearly and specifically defined.

[0059] In an optional embodiment, the front wing 11 is provided with a pair, and the two front wings 11 are about the fuselage 10 (i.e., the symmetry plane Ox of the aircraft). b z b In a preferred embodiment, the two canards 11 are symmetrically mounted on both sides of the head 101, providing the aircraft with trim positive lift, and at the same time, in conjunction with the wing 12 and the horizontal tail 13, enhancing the anti-stall spin capability of the aircraft 1 and improving flight safety.

[0060] With the rapid development of global aviation, wings with longer and thinner structural features can obtain more effective aerodynamics. In addition, the larger the aspect ratio of the wing, the larger the lift coefficient of the wing, and the smaller the induced drag, which means that wings with higher aspect ratios can obtain more effective lift, thereby increasing the subsonic range of the aircraft, reducing fuel consumption and improving fuel efficiency. In the following text and throughout the specification, the term "aspect ratio" is the ratio of the wingspan to the average geometric chord length, the term "wingspan" is the straight-line distance from one wingtip to another wingtip, and the term "chord" is the line between the leading edge and the trailing edge of the wing. In order to increase the aspect ratio of the wing, it can be achieved by increasing the wingspan without changing the chord. Increasing the wingspan is an effective way to increase the aspect ratio of the wing to reduce the induced drag and increase the lift coefficient. Therefore, in order to pursue higher cruising efficiency, civil transport aircraft need wings with a larger aspect ratio. The current wing designs are all cantilevered to the fuselage. When pursuing a high aspect ratio wing design, considering stiffness, strength and other issues, it is often necessary to pay a huge structural weight price. For aircraft with a low-wing layout, it is extremely difficult to install and design a high bypass ratio turbofan engine. In addition, there is an upper limit to the design potential of the lift-enhancing device, and the improvement of the aircraft's aerodynamic efficiency will also be limited. To solve this problem, the aerodynamic layout of the three-wing aircraft 1 was further improved:

[0061] Reference Figure 1 to Figure 3 The aerodynamic layout of the three-wing aircraft 1 also includes a diagonal strut 18, and the wing 12 is in the span direction (i.e., the transverse axis Oy bThe wing 12 has a fixed end and a free end that are separated from each other in the direction of the fixed end, and the wing 12 is fixedly connected to the fuselage 10 through the fixed end; the diagonal brace 18 is fixedly connected obliquely between the fixed end and the fuselage 10, so that the wing, the diagonal brace and part of the fuselage 10 are connected in sequence around and form a triangular support structure. The triangular support structure as described above allows the wing 12 to adopt an aerodynamic layout with a large aspect ratio and a small sweep angle.

[0062] In the following text and throughout the specification, the term "sweep angle" is understood to mean the angle between the wing and the longitudinal axis Ox of the fuselage. b The angle between the vertical lines of the leading edge and the trailing edge is defined as positive for back sweep and negative for forward sweep. The sweep angle measured by the leading edge line, the quarter chord line or the trailing edge line is called the leading edge sweep angle x0, the quarter chord sweep angle x 0.25 and trailing edge sweep angle x 1.0 The term "high wing" should be understood as the installation height of the wing relative to the fuselage. According to the installation position, the wing can be divided into high wing, mid wing and low wing. The wing installed above the fuselage is a high wing, the wing installed in the middle is a mid wing, and the wing installed below the wing is a low wing.

[0063] Furthermore, the wing 12 includes an inner wing 125 and an outer wing 126 arranged in sequence from the inner side to the outer side in the wingspan direction; the sweep angle of the diagonal strut 18 is opposite to the sweep angle of the inner wing 125. Figure 2 It can be seen in the illustrated embodiment that when the inner wing 125 is arranged to be swept back, the diagonal strut 18 is arranged to be swept forward. At this time, the sweep angle of the inner wing 125 is 0° to 40°, and the sweep angle of the diagonal strut 18 is 0° to -40°.

[0064] exist Figure 3 It can be seen in the illustrated embodiment that when the inner wing 125 is arranged to be swept forward, the diagonal strut 18 is arranged to be swept backward. At this time, the forward sweep angle of the inner wing 125 is 0° to 40°, and the backward sweep angle of the diagonal strut 18 is 0° to -40°.

[0065] Refer again Figure 2 and Figure 3 The outer wing 126 is arranged to be swept. In an optional embodiment, the sweep angle of the outer wing 126 is 0° to 25°.

[0066] Refer again Figure 2 In a preferred embodiment, the leading edge sweep angle of the inner wing 125 is The angle is 20°, and the trailing edge sweep angle of the inner wing 125 The angle of the outer wing 126 is 20°; the leading edge sweep angle The angle is 12°, and the trailing edge sweep angle of the outer wing 126 is The angle is 8°; the leading edge sweep angle of the diagonal brace 18 The angle is -15°.

[0067] Refer again Figure 3 In a preferred embodiment, the leading edge sweep angle of the inner wing 125 is The angle is -20°, and the trailing edge sweep angle of the inner wing 125 The angle of the outer wing 126 is -20°; the leading edge sweep angle The angle is 12°, and the trailing edge sweep angle of the outer wing 126 is The angle is 8°; the leading edge sweep angle of the diagonal brace 18 The angle size is 15°.

[0068] Furthermore, a wing platform 19 is provided on the top of the fuselage 10, and the wing 12 is fixedly connected to the fuselage 10 via the wing platform 19, so that the wing 12 is arranged into an upper single-wing aerodynamic layout.

[0069] Thus, by adopting the above aerodynamic layout, the diagonal brace 18 with a swept angle can be used under the wing 12 to bear most of the load of the outer wing 126, bringing some structural benefits. The wing platform 19 can increase the installation height of the wing 12, increase the angle between the diagonal brace 18 and the wing, and further improve the use efficiency of the diagonal brace 18. Thus, through this diagonal brace support method, the aspect ratio of the wing can be increased to more than 15 or even to 25, and the wing can also be made thinner.

[0070] Reference Figure 1 The front landing gear 103 is installed under the head 101 of the fuselage 10, and the main landing gear 104 is installed under the rear of the fuselage 10. Since the whole machine adopts an upper wing aerodynamic layout, the length of the landing gear strut can be shortened, the pilot's ground vision for takeoff and landing can be increased, and the center of gravity of the aircraft can be lowered, thereby improving airport applicability.

[0071] In the following text and throughout the specification, the term "dihedral angle" refers to the angle between the reference plane and the horizontal plane. When the wing is twisted, it refers to the angle between the twist axis and the horizontal plane. When the dihedral angle is negative, it is called anhedral angle.

[0072] According to the installation position of the canard 11 , the canard 11 has a downward anhedral aerodynamic layout. In an optional embodiment, the downward anhedral angle of the canard 11 is 0° to 10° to prevent the wake of the canard from interfering with the diagonal strut 18 .

[0073] Reference Figure 1 and Figure 2The wing 12 is provided with a pair, and the two wings 12 are arranged symmetrically with respect to the fuselage 10; the first propulsion unit 17 is arranged to be composed of at least one propulsion subset, each of the propulsion subsets includes a pair of the first propulsion units 17 arranged symmetrically with respect to the fuselage 10, and each first propulsion unit 17 in each propulsion subset is fixedly mounted to a corresponding wing 12.

[0074] Refer again Figure 1 , the tail strut 14 is provided with a pair, and the two tail struts 14 are arranged symmetrically with respect to the fuselage 10; the vertical tail 15 is provided with two pieces to form a double vertical tail structure, each piece of the vertical tail 15 is fixedly connected to the end of a corresponding tail strut 14, and the horizontal tail 13 is fixedly connected between the two pieces of the vertical tail 15, and the double vertical tail structure can enhance the heading stability of the aircraft. In a preferred embodiment, the installation height of the horizontal tail 13 is higher than the installation height of the wing 12, so that the horizontal tail 13 is less affected by the downwash of the wing 12, and the use efficiency of the horizontal tail elevator 131 is ensured.

[0075] Reference Figure 1 , Figure 4 and Figure 5 The second propulsion unit 16 is a propulsion device with a foldable propeller or a propeller fan, and the second propulsion unit 16 includes:

[0076] an engine, the engine being mounted to the tail section 102;

[0077] a power output shaft, the power output shaft being drivingly connected to the engine, the power output shaft extending rearwardly along the longitudinal axis of the fuselage 10 and emerging from the engine to form a central cone 162;

[0078] at least two blades 161 spaced apart from each other, the roots of the blades 161 being hinged to the central cone 162; and

[0079] a reset component, which is disposed on the central cone 162 and acts on the paddle 161, so that the paddle 161 rotates relative to the central cone 162 to switch from an extended state to a retracted state;

[0080] When the paddles 161 are in the unfolded state, the paddles 161 are radially arranged on the periphery of the central cone 162; when the paddles 161 are in the folded state, the paddles 161 gather to the periphery of the central cone 162. In an optional embodiment, the reset component can be implemented by using a torsion spring at the root hinge of the foldable paddles 161.

[0081] As a further improvement, continue to refer to Figure 1The three-wing aircraft 1 can use the first propulsion unit 17 to provide thrust during the cruising phase; and use the first propulsion unit 17 and the second propulsion unit 16 to jointly provide thrust during the take-off, climb and landing go-around phases.

[0082] Furthermore, the first propulsion unit 17 is a propulsion device with a propeller or a propeller fan, and the wing control surface of the wing 12 is arranged behind the propeller or the propeller fan, wherein the wing control surface can be at least one of a flap, a flaperon and an aileron.

[0083] Specifically, during the takeoff, climb and landing go-around phases, when the second propulsion unit 16 is working, the propeller blades 161 rotate from the folded state to the expanded state by virtue of centrifugal force to generate additional thrust. During the cruising phase or when the second propulsion unit 16 stops working, the blades 161 are folded into the folded state by virtue of the reset parts at the root hinges, and gathered around the rod-shaped central cone 162, thereby reducing the resistance during flight and preventing the blades 161 from overlapping each other after being folded, causing collision and damage when the blades 161 are reopened and rotated.

[0084] In an optional embodiment, the first propulsion unit 17 is a low-power propulsion device, and the second propulsion unit 16 is a single-engine high-power auxiliary propulsion device. The multiple low-power propulsion devices drive small-diameter propellers to provide the thrust required for the entire flight, and at the same time increase the lift of the wing 12. There are several left and right propulsion units, which are symmetrically distributed on both sides of the fuselage 10 and installed in front of the wing 12 to achieve the power increase of the propeller slipstream on the wing 12. The number of the first propulsion units 17 is 2 to 16, and 10 are taken as an example in this embodiment. The wing trailing edge flap 122, flaperon 123 and aileron 124 are behind the multiple low-power propulsion devices. During the take-off, climb and landing go-around stages, the wing trailing edge flap 122 and flaperon 123 are deflected downward, and under the influence of the propeller slipstream effect, the lift of the whole aircraft is increased, the take-off and landing speeds are reduced, and the take-off and landing run distances are shortened. The aileron 124 in the propeller slipstream can also increase the control efficiency at low speeds. During the cruise phase, the wing trailing edge flaps 122 and flaperons 123 are retracted to a cruise clean configuration.

[0085] As a further improvement, the first propulsion unit 17 and / or the second propulsion unit 16 are electrically driven.

[0086] Refer again Figures 1 to 3The canard 11 may further include a canard elevator 111, and the horizontal tail 13 may further include a horizontal tail elevator 131; the canard elevator 111 and the horizontal tail elevator 131 change the pitch moment of the aircraft through reverse differential upward and downward deflection to control the pitch attitude of the aircraft; the canard elevator 111 and the horizontal tail elevator 131 adjust the magnitude of the aircraft's level flight lift by simultaneously deflecting upward or downward, thereby being able to perform altitude translation on the aircraft without changing the aircraft's attitude.

[0087] Specifically, the canard elevator 111 and the horizontal tail elevator 131 have two usage modes: for the pitch attitude, the canard elevator 111 is deflected downward and the horizontal tail elevator 131 is deflected upward, thereby controlling the aircraft attitude to pitch upward, or the canard elevator 111 is deflected upward and the horizontal tail elevator 131 is deflected downward, thereby controlling the aircraft attitude to pitch downward; for the aircraft's altitude translation, the canard elevator and the main wing elevator are deflected downward at the same time to control the aircraft to translate upward, and the canard elevator and the main wing elevator are deflected upward at the same time to control the aircraft to translate downward.

[0088] To sum up, the first propulsion unit 17 on the wing 12 can continue to work during cruising, with electricity provided by a hydrogen fuel cell or a turbine prime mover driving a generator, and the wing 12 in the propeller slipstream continues to be affected by the favorable lift increase. Compared with traditional aircraft, the three-wing aircraft of this embodiment can generate greater lift using a wing of the same area, so that the aircraft can fully obtain the overall benefits brought by a wing with a large aspect ratio, a small area, and a high wing load.

[0089] In addition, the maximum power and mechanical strength of the first propulsion unit 17 only need to meet the aircraft's cruising and route climbing capabilities. Unlike traditional aircraft, there is no need to pay the price for the maximum take-off thrust state on the ground, which also brings weight benefits.

[0090] Finally, the high-power working time period of the single-engine second propulsion unit 16 at the tail of the fuselage only needs to meet the requirements of take-off, climb and landing and go-around, and each high-power duration is very short. It can be powered by lithium batteries and charged by the generator driven by the hydrogen fuel cell or turbine prime mover of the first propulsion unit 17 during the cruise phase. The second propulsion unit 16 can make full use of the short-term high-power capacity of lightweight lithium batteries and motors, thereby obtaining the overall benefit of lightweighting the entire aircraft power system.

[0091] The technical solution of the present application can achieve at least the following beneficial effects:

[0092] This case adopts a three-wing aerodynamic layout and installs a multi-engine first propulsion unit on the wing, while achieving power increase on the wing. Especially during takeoff, climb, and landing go-around, the wing trailing edge flaps, flaperons, and ailerons are deflected downward, and the trailing edge flaps, flaperons, and ailerons are affected by the slipstream effect of the propulsion unit, further increasing the lift of the entire aircraft and reducing the takeoff and landing speeds. The ailerons in the slipstream can also increase the control efficiency at low speeds; at the same time, the single-engine second propulsion unit also generates additional thrust during takeoff, climb, and landing go-around, shortening the takeoff and landing run distances and increasing the aircraft's climb rate, improving the overall efficiency of the entire flight mission, reducing energy consumption during flight, and meeting the green aviation requirements of aircraft energy saving, emission reduction, and noise reduction.

[0093] The aircraft in this case can be a general aviation transport aircraft or a large commercial aircraft, including a fuselage, a canard, a wing, a wing diagonal brace with a swept angle, a multi-engine low-power propulsion device, a single-engine high-power auxiliary propulsion device with a foldable electric propeller / propeller fan, a vertical tail, a horizontal tail, a winglet, a trailing edge flap, a flaperon, an aileron, an elevator (including a canard elevator) and a rudder, a front landing gear, and a main landing gear. In an optional embodiment, the multi-engine low-power propulsion device is electrically driven. The multi-engine low-power propulsion device drives a small-diameter propeller to provide the thrust required for the entire flight and increase the lift of the wing. There are several on each side, symmetrically distributed on both sides of the fuselage, and installed in front of the wing. The single-engine high-power auxiliary propulsion device of the foldable electric propeller / propfan is installed at the tail of the fuselage and works during takeoff, climb and landing go-around phases. When the electric propeller / propfan is working, the propeller blades open due to centrifugal force. When the electric propeller / propfan is not working, the blades are folded into a retracted state due to the torsion spring force at the root hinge, thereby reducing resistance during flight.

[0094] The overall aerodynamic layout of the aircraft in this case adopts a wing with a large aspect ratio and a small sweep angle. The large aspect ratio can reduce the induced drag of the wing and improve the aerodynamic efficiency of the cruise. The smaller sweep angle reduces the lateral disturbance of the airflow on the wing surface, so that the wing can adopt a laminar design and reduce the friction resistance of the aircraft. The diagonal struts with a sweep angle are used under the wing to bear most of the load of the external wing, so that the load on the inner wing of the large aspect ratio wing is reduced, bringing some structural benefits. When the inner wing of the wing is swept back, the diagonal struts are swept forward; when the inner wing of the wing is swept forward, the wing struts are swept back. The triangular structural design of both in the top view and the front view of the aircraft can not only provide strength and stiffness in multiple directions, but also is conducive to the area law distribution characteristics, which can reduce the shock wave resistance or interference resistance during subsonic flight. In addition, the presence of the diagonal struts can make the airfoil of the wing thinner, significantly reducing the shock wave resistance during subsonic flight. The canard is installed under the fuselage head. When the aircraft is trimmed for flight, the canard can provide positive lift and ensure that the canard stalls before the main wing and the horizontal tail at high angles of attack, so that there is enough nose-down restoring moment to improve the high angle of attack characteristics. The horizontal tail is installed in the middle of the double vertical tail and connected to the wing through the tail strut. The height of the horizontal tail is higher than the wing, so that the horizontal tail is less affected by the downwash of the wing. Generally speaking, this layout of the passenger aircraft has good aerodynamic characteristics.

[0095] In this case, multiple low-power propulsion devices can be installed on the wings, symmetrically distributed in front of the wings, and the power of the wings can be increased at the same time. Especially during takeoff, climb, and landing go-around, the wing trailing edge flaps, flaperons, and ailerons are deflected downward, and the trailing edge flaps, flaperons, and ailerons are affected by the propeller slipstream effect, further increasing the lift of the entire aircraft and reducing the take-off and landing speeds. The ailerons in the propeller slipstream can also increase the control efficiency at low speeds. The single-engine high-power auxiliary propulsion device of the foldable electric propeller / propeller fan also rotates and unfolds from the folded state during takeoff, climb, and landing go-around, generating additional thrust, shortening the takeoff and landing run distances, and increasing the aircraft's climb rate. The power is provided by lithium batteries. The capacity of the lithium battery should ensure the superposition requirements of takeoff, initial climb, and landing go-around, and retain an appropriate margin. During the cruise phase, only multiple-engine low-power propulsion devices are used, and the trailing edge flaps and ailerons are retracted to a clean cruise configuration. At this time, a turbine prime mover that consumes fuel is used to drive a generator to provide electricity or a fuel cell that consumes hydrogen fuel to provide electricity to the multiple-engine low-power propulsion devices, while charging the lithium battery of the single-engine high-power auxiliary propulsion device.

[0096] Specifically, the single-engine high-power auxiliary propulsion device of the foldable electric propeller / propeller fan rotates and unfolds the blades during takeoff, climb and landing go-around, generating thrust while inhaling the fuselage boundary layer. Fuselage boundary layer inhalation can control the development of the boundary layer, inhibit boundary layer separation, reduce aircraft resistance, improve the aircraft's climb rate, and reduce energy consumption.

[0097] The above is a detailed introduction to the aerodynamic layout of a three-wing aircraft provided by an embodiment of the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the technical solutions and core ideas of the present invention. Ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An aerodynamic layout of a three-wing aircraft, characterized in that: include: a fuselage having a head portion and a tail portion facing away from each other; A front wing and a wing, wherein the front wing and the wing are fixedly connected to the fuselage in sequence from front to back; A tail strut, the tail strut being fixedly connected to the wing or the fuselage and extending rearward; A vertical tail fin, the vertical tail fin being fixedly connected to the end of the tail strut; as well as A horizontal tail wing, the horizontal tail wing being fixedly connected to the tail strut or the vertical tail wing; Wherein, at least two first propulsion units are fixedly mounted on the wing, and the first propulsion unit is a propulsion device with a propeller or a propeller fan; The tail is fixedly mounted with a second propulsion unit, which is a propulsion device with a foldable propeller or a propeller fan; The first propulsion unit and / or the second propulsion unit are electrically driven; The first propulsion unit is used to provide thrust during the cruise phase; the first propulsion unit and the second propulsion unit are used together to provide thrust during the take-off, climb and landing go-around phases.

2. The aerodynamic layout according to claim 1, characterized in that: It also includes a diagonal strut, and the wing has a fixed end and a free end that are away from each other in the wingspan direction, and the wing is fixedly connected to the fuselage through the fixed end; the diagonal strut is fixedly connected obliquely between the vicinity of the fixed end and the fuselage, so that the wing, the diagonal strut and part of the fuselage are connected around each other in sequence to form a triangular support structure.

3. The aerodynamic arrangement according to claim 2, characterized in that: The wing comprises an inner wing and an outer wing which are arranged in sequence from the inner side to the outer side in the wingspan direction; the sweep angle of the diagonal strut is opposite to the sweep angle of the inner wing.

4. The aerodynamic arrangement according to claim 3, characterized in that: When the inner wing is arranged to be swept back, the diagonal strut is arranged to be swept forward. At this time, the sweep angle of the inner wing is 0° to 40°, and the sweep angle of the diagonal strut is 0° to -40°.

5. The aerodynamic arrangement according to claim 3, characterized in that: When the inner wing is arranged to be swept forward, the diagonal strut is arranged to be swept backward. At this time, the forward sweep angle of the inner wing is 0° to -40°, and the backward sweep angle of the diagonal strut is 0° to 40°.

6. The aerodynamic arrangement according to claim 3, characterized in that: The outer wing is arranged to be swept back, and the sweep angle of the outer wing is 0° to 25°.

7. The aerodynamic arrangement according to any one of claims 1 to 6, characterized in that: The wing is a high-wing aerodynamic layout.

8. The aerodynamic arrangement according to claim 7, characterized in that: A wing platform is provided on the top of the fuselage, and the wing is fixedly connected to the fuselage through the wing platform.

9. The aerodynamic arrangement according to any one of claims 1 to 6, characterized in that: The aspect ratio of the wing is 15-25.

10. The aerodynamic arrangement according to any one of claims 1 to 6, characterized in that: The canards are provided with a pair, and the two canards are arranged symmetrically with respect to the fuselage; the canards are of an anhedral aerodynamic layout, and the anhedral angle of the canards is 0° to 10°.

11. The aerodynamic arrangement according to claim 10, characterized in that: The two front wings are symmetrically installed on both sides of the head.

12. The aerodynamic arrangement according to any one of claims 1 to 6, characterized in that: The wings are provided with a pair, and the two wings are arranged symmetrically with respect to the fuselage; the first propulsion unit is arranged to be composed of at least one propulsion subset, each of the propulsion subsets includes a pair of the first propulsion units arranged symmetrically with respect to the fuselage, and each first propulsion unit in each propulsion subset is fixedly mounted to a corresponding wing.

13. The aerodynamic arrangement according to any one of claims 1 to 6, characterized in that: The tail struts are provided in pair, and the two tail struts are arranged symmetrically with respect to the fuselage; the vertical tail is provided with two pieces, each piece of the vertical tail is fixedly connected to the end of a corresponding one of the tail struts, and the horizontal tail is fixedly connected between the two pieces of the vertical tail.

14. The aerodynamic arrangement according to claim 13, characterized in that: The installation height of the horizontal tail is higher than the installation height of the wing.

15. The aerodynamic arrangement according to any one of claims 1 to 6, characterized in that: The second propulsion unit comprises: an engine, the engine being mounted to the tail; a power output shaft, the power output shaft being drivingly connected to the engine, the power output shaft extending rearwardly along the longitudinal axis of the fuselage and emerging from the engine to form a central cone; at least two spaced-apart blades, the roots of the blades being hinged to the central cone; and a reset component, the reset component being arranged on the central cone and acting on the blades, so that the blades rotate relative to the central cone to switch from an extended state to a retracted state; Wherein, when the blades are in the deployed state, the blades are radially arranged on the periphery of the central cone; when the blades are in the retracted state, the blades gather to the periphery of the central cone.

16. The aerodynamic arrangement according to any one of claims 1 to 6, characterized in that: The wing control surface of the wing is arranged behind the propeller or propfan of the first propulsion unit.

17. The aerodynamic arrangement according to claim 16, characterized in that: The wing control surface includes at least one of a flap, a flaperon and an aileron.

18. The aerodynamic arrangement according to any one of claims 1 to 6, characterized in that: The canard also includes a canard elevator, and the horizontal tail also includes a horizontal tail elevator; the canard elevator and the horizontal tail elevator change the pitch moment of the aircraft through reverse differential upward and downward deflection, thereby controlling the pitch attitude of the aircraft; the canard elevator and the horizontal tail elevator adjust the magnitude of the aircraft's horizontal flight lift by simultaneously deflecting upward or downward, thereby being able to perform altitude translation of the aircraft without changing the aircraft's attitude.

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