A combined wing system based on distributed ducted fans and its application method

Abstract

The present invention provides a combined wing system based on distributed ducted fans and an application method thereof. The combined wing system is arranged on both sides of a flying car and includes: wings symmetrically arranged on both sides of the flying car, the wings including an inner wing, an outer wing arranged in sequence along the direction from near to far from the cockpit, and a leading-edge slat and a trailing-edge flap arranged on the inner wing; a plurality of ducted fans parallel to the aerodynamic chord and deflectable downward at uniform intervals are installed on the trailing-edge flap; the airfoil leading and trailing edges of the outer wing are opposite to those of the inner wing, and the trailing edge is in front. When the EDF works, the present invention guides the airflow to flow through the upper surface of the wing by means of air suction, generating negative pressure. Although the wing does not move forward during vertical takeoff, induced lift will also be generated, forming a resultant force with the upward reaction force of the EDF jet, pushing the entire flying car to a high altitude. An outer wing with an installation angle is designed to further increase lift and reduce drag. At the same time, a high-lift airfoil is adopted to efficiently improve the lift-to-drag ratio and effectively improve the flight efficiency.

Description

Technical Field

[0001] The present invention relates to the field of aviation engineering technology, in particular, to the field of aircraft aerodynamics overall design technology in the aviation field; specifically, to a combined wing system based on a distributed ducted fan and an application method thereof. Background Art

[0002] At present, there is a global upsurge in the development of electric vertical take-off and landing (eVTOL) aircraft suitable for modern urban three-dimensional transportation planning (UAM). However, although the general direction of the development of electric vertical take-off and landing (eVTOL) aircraft is correct at this stage, there is also a one-sided tendency to focus on algorithms, despise efficiency, and ignore aerodynamics.

[0003] Therefore, the eVTOL aircraft that have been made public, operated or tested so far have various shapes and no unified form, and their performances are varied and there are no standardized empirical requirements. The data in Table 1 below are collected from the published literature, which can generally reflect some of the current problems.

[0004] Table 1

[0005]

[0006] The rightmost column in Table 1 is called "Vertical Takeoff Induced Lift Ratio", which is an indicator of the flight efficiency of the eVTOL device. As we all know, there are two mechanisms for generating vertical force:

[0007] (1) Direct force or Newton’s reaction force, referred to as Newton’s force;

[0008] (2) Induced force, or Bernoulli force. Bernoulli force is the induced lift force induced by Newtonian force. Bernoulli force is a field force orthogonal to Newtonian force and has high efficiency.

[0009] The vertical force of an aircraft always includes these two forces, and it is always hoped that the induced lift contained in the vertical force will account for a higher proportion. The formula for calculating the proportion of induced lift in vertical takeoff is:

[0010] ε = induced lift / total lift = 1.0 – thrust-to-weight ratio (s);

[0011] According to this formula, the data in the rightmost column of Table 1 can be calculated. A + (positive) or - (negative) sign is prefixed to ε. The + sign indicates the presence of induced lift, and the larger the number, the higher the proportion of induced lift; the - sign indicates that the vertical force only contains Newtonian force and no Bernoulli force, and the larger the number after the - sign, the lower the efficiency. The ε of traditional helicopters is approximately between 0 and -8. The mechanical mechanism of eVTOL aircraft is essentially the same as that of traditional helicopters. Generally, the ε of eVTOL aircraft should be close to 0~-8. For those with high efficiency, ε is positive. The larger the positive value, the higher the design level and the better the energy conservation and emission reduction. However, as can be seen from Table 1, among the 14 products, only 6 products have an induced lift proportion higher than +50%. 7 products have a negative ε, and for some individual products, it even reaches an astonishing -260, consuming a large amount of energy.

[0012] In addition, some eVTOL aircraft do not consider the overall optimization but follow the mode of traditional helicopters flying horizontally with the nose down, that is, the proportion of induced lift during cruise horizontal flight is very low, even negative, the lift-to-drag ratio in level flight is small, and a large amount of energy is consumed. In this mode of flying horizontally with the nose down, considering the constraints such as low battery energy density and long charging time, there are drawbacks: it cannot fly far, fast, and can carry few passengers / cargo.

[0013] One of the eVTOLs – Lilium Jet is different from other eVTOL devices. The "proportion of induced lift during vertical takeoff" σ of Lilium Jet is as high as 62% (as shown in Table 1); the lift-to-drag ratio during horizontal cruise flight is as high as 21, flying faster than other devices, reaching 300 km / h, flying farther than other devices, reaching 350 km, and carrying 5 passengers. Its comprehensive performance is excellent and the flight efficiency is very high. It can be said to be one of the best eVTOL devices at present. The main reason is that ducted fans (EDFs) are placed at the trailing edge of the wing. When the EDFs work, by sucking air, the airflow is guided to flow over the upper surface of the wing, generating negative pressure. Thus, during the vertical takeoff phase, even if the wing does not move forward, the wing generates induced lift, that is, Bernoulli force. The resultant force of the induced lift and the reaction force (upward) of the Newtonian force generated by the EDF jet pushes the entire aircraft into the sky. Practice has proved that with 38% of the Newtonian force, 62% of the Bernoulli force can be induced. During the cruise level flight phase, the EDFs placed at the rear of the wing on the one hand can blow away the boundary layer on the upper wing surface, reducing the zero-lift drag, and on the other hand, it also accelerates the local airflow velocity on the upper wing surface, increasing the lift of the wing. The results of these two effects greatly improve the lift-to-drag ratio and the flight efficiency.

[0014] However, there are still the following problems and challenges for the existing eVTOL aircraft that use EDFs for flow diversion and lift augmentation at the present stage:

[0015] 1. The current EDF combined wing does not take measures to reduce induced drag. Although the lift-to-drag ratio has been increased to a certain extent, the increase is not large enough.

[0016] 2. The current EDF combined wing is only applied to fixed straight wings, becoming a general aviation aircraft with a large wingspan and vertical takeoff and landing capabilities. It cannot drive on ordinary roads and needs to be towed to a specified airport for takeoff or landing. It cannot take off or land anytime and anywhere in narrow urban streets and alleys without a large area of open space, so its applicability is greatly limited.

[0017] 3. The ducted fans of eVTOL aircraft are all installed on the trailing-edge flaps of the wings. The installation of EDF on the trailing-edge flaps is implemented only by experience. There is no clear standard design for the length of the flaps, nor is it determined which position of the leading edge of the flaps is the most reasonable to be set on the aerodynamic chord (average aerodynamic chord length), and there is no optimized solution.

[0018] 4. There is no standard structural design for the airfoil section of the wing paired with the ducted fan EDF.

[0019] 5. The current ducted fan EDF cannot be applied to large flying saucer configurations, large-load, multi-passenger sightseeing carriers.

[0020] 6. The current eVTOL aircraft does not have emergency rescue equipment and cannot carry out self-rescue in case of an accident. Summary of the Invention

[0021] In view of this, the purpose of the present invention is to propose a combined wing system based on distributed ducted fans and its application method. The distributed ducted fans EDF are arranged on the trailing-edge flaps of the wings. When the EDF works, the airflow is guided to flow over the upper surface of the wings by the suction method, generating negative pressure. During vertical takeoff, although the wings do not move forward, the wings will also generate induced lift. The induced lift and the upward reaction force of the EDF jet form a resultant force to push the entire flying car to a high altitude. In addition, the outer wings with installation angles are designed to further increase lift and reduce drag, and high-lift airfoils are adopted to efficiently increase the lift-to-drag ratio. The front and rear edges of the airfoil of the outer wings are opposite to those of the inner wings, and the trailing edge is placed in front to reduce the induced drag of the whole aircraft and further increase the lift-to-drag ratio and improve the flight efficiency. Moreover, the structure of the combined wing system is simple, reasonable, and has a low cost, which is conducive to popularization and application.

[0022] The present invention provides a combined wing system based on distributed ducted fans, which is arranged on both sides of a flying car and includes: wings symmetrically arranged on both sides of the flying car, the wings including an inner wing, an outer wing arranged in sequence along the direction from near to far from the cockpit, and a leading-edge slat and a trailing-edge flap arranged on the inner wing; a plurality of ducted fans (EDFs) parallel to the aerodynamic chord and evenly spaced are installed on the trailing-edge flap and can deflect downward following the trailing-edge flap; the airfoil leading and trailing edges of the outer wing are opposite to those of the inner wing, and the trailing edge is in front.

[0023] The combined wing system of the present invention can be installed on a unified air-land amphibious flying car. Among them, the inner wing is the main wing, and the outer wing is used to counteract drag and increase lift. Preferably, the length of the inner wing accounts for 2 / 3 of the semi-span length of the flying car (half of the distance between the left and right wing tips of the two wings on both sides), and the length of the outer wing accounts for 1 / 3 of the semi-span length. The distributed ducted fans EDF act as a thrust vector control system. After starting vertical (in the vertical direction) takeoff, a plurality of ducted fans EDF (preferably 32-36 in total) on both sides of the vehicle body are evenly distributed along the wingspan direction of the vehicle body and can take off smoothly. The distributed ducted fans EDF are placed at the trailing-edge flap of the wing. When the EDF works, the airflow is guided to flow through the upper surface of the wing by the suction method, generating negative pressure. During vertical takeoff, although the wing does not move forward, the wing will also generate induced lift (i.e., Bernoulli force). The induced lift and the upward Newtonian force reaction force generated by the EDF jet form a resultant force, pushing the entire flying car to a high altitude. The structure of this combined wing system is simple, reasonable, and has a low cost, bringing an unexpected lift-increasing effect. This EDF combined wing can be placed on both the left and right sides of the fuselage during vertical takeoff and landing, without stretching left and right. After taking off, it can stretch left and right, which can greatly shorten the lateral (wingspan) scale of the aircraft and can vertically take off and land in big cities, mountainous areas, or on aircraft carriers, ship decks, or even roads with relatively narrow spaces, and has looser requirements for the takeoff and landing sites.

[0024] The combined wing system (EDF combined wing) can be used as an independent unit. Preferably, multiple such EDF combined wings can be combined and used according to actual needs.

[0025] Preferably, a wingtip vortex generator is arranged at the outer end of the outer wing. The wingtip vortex generator generates a vortex with a rotation direction opposite to that of the wingtip vortex, preventing the airflow on the lower wing surface from flowing back to the upper wing surface through both ends of the wing, thereby reducing the lift loss of the airfoil from two-dimensional theory to three-dimensional application. It reduces the intensity of the wingtip downwash flow, reduces the induced drag, and can improve the flight performance.

[0026] Furthermore, a plurality of the ducted fans (EDF) are vertically arrayed evenly and equidistantly along the circumferential direction of the circle, and are connected end to end to form a combined ring wing. The combined ring wing is applied to a planar annular wing, and the outer circle of the combined ring wing is the leading edge of the planar annular wing.

[0027] Preferably, the width of the combined annular wing is 75% of the aerodynamic chord length, and the diameter of the combined annular wing is equal to about one-fourth of the aerodynamic chord length.

[0028] Preferably, when designing the geometric parameters of the planar annular wing of a flying car, after the circumferential arrangement and fixation of the EDF combination, the outer circle of the EDF combination is used as the inner circle of the planar annular wing, and the principle of the induced lift of the annular EDF is the same as that of the combined straight wing of the EDF.

[0029] After determining the geometric parameters of the planar annular wing, preferably, a high-lift airfoil section is designed or selected. Usually, an airfoil with a relatively large thickness (25% - 35%) is selected to obtain high lift. In addition, when designing the airfoil, to reduce the induced drag, the lower head can be adopted to move the stagnation point of the airfoil downward.

[0030] The planar annular wing with a combined annular wing can be applied to large flying saucer configurations, large-load, multi-passenger sightseeing carriers.

[0031] Preferably, the aerodynamic chord of the airfoil of the section of the planar annular wing makes an installation angle of +15° with the horizontal plane (the installation angle can be adjusted through experiments).

[0032] This EDF combined annular wing can be understood as being formed by a very long combined straight wing of the EDF rotating 360° in the horizontal plane around a closed circumference and then being connected end to end. The EDF combined annular wing has the following excellent aerodynamic characteristics: infinite wingspan, two-dimensional airfoil, almost no stall, high lift, 100% induced lift, and zero drag. Since the multiple ducted fans are axisymmetric, the resultant force in the horizontal plane is zero, that is, the drag is zero, improving the flight efficiency.

[0033] Furthermore, a flap spanwise rotating shaft along the wingspan direction is provided on the trailing edge flap, and the flap spanwise rotating shaft penetrates through the inner wing and the outer wing; a leading edge slat is provided near the wing tip at the leading edge of the wing, and the front half wing of the wing can rotate around the flap spanwise rotating shaft.

[0034] Preferably, the front half wing of the wing is arranged at 75% of the aerodynamic chord length; the front half wing can rotate 90° forward and downward around the flap spanwise rotating shaft, and the trailing edge flap can rotate 90° backward and downward.

[0035] When taking off vertically (in the vertical direction), the front half-wings of both wings (at 75% of the aerodynamic chord length) rotate 90° obliquely upward from the vertical state around the flap spanwise rotation axis to enter the working state, rotating the front half-wings at the front of the combined wing to the horizontal plane state, and then locking. The rear half-wings of the wings (trailing edge flaps) deflect 90 degrees backward and downward, making the EDF perpendicular to the ground. The combined wing is always parallel to the vehicle body (the wingspan remains parallel to the vehicle body), and there is no need to rotate the wings to a position perpendicular to the vehicle body during the vertical takeoff stage because there is no speed moving forward or in other directions at this time. The wings themselves have no aerodynamic force. The working principle of the ducted fan combined wing determines that it is independent of the wing orientation in the initial stage. The advantage of not having to rotate the wings to be perpendicular to the vehicle body during the vertical takeoff stage is that the lateral (spanwise) dimension of the flying car during takeoff is very short.

[0036] After the flying car ascends and hovers in the air and is about to switch to cruise flight, the front half-wings of both wings rotate 90° horizontally forward towards the front of the aircraft around the flap spanwise rotation axis, converting the wing orientation in the air into a fixed-wing aircraft configuration.

[0037] The combined wing has two rotational degrees of freedom: rotating left and right in the horizontal plane around the vertical axis and rotating up and down in the vertical plane around the horizontal axis.

[0038] Furthermore, a vertical hinge axis is provided at the connection between the spanwise (lateral) direction of the wing and the main beam of the vehicle body of the flying car, and the wing can rotate and fold around the hinge axis.

[0039] The wing can be folded around the vertical rotation axis, facilitating the collection of both the wing and the two EDF thrust vector control systems on the outside of both sides of the vehicle body. When driving on the ground, it looks like an ordinary SUV car, solving the problems that traditional eVTOL aircraft cannot drive on ordinary roads and cannot take off or land anytime and anywhere in narrow urban streets and alleys without large open spaces, improving the applicability.

[0040] Preferably, another rotation axis is provided near the inner wing angle of the EDF combined wing. The hinge axis and the other rotation axis form a linkage mechanism through a connecting rod. The linkage mechanism connects the wing and the main beam of the vehicle body, enhancing the smoothness and reliability of the wing rotation.

[0041] Furthermore, two large-diameter (high-power) ducted fan EDFs are installed at the rear of the flying car as control vector actuators, and the large-diameter ducted fan EDFs are arranged vertically upward.

[0042] The flying car of the present invention does not install a traditional aerodynamic control system. Instead, two high-power (large-diameter) ducted fans EDF installed on the rear horizontal plane are used to replace the traditional aerodynamic control system. By changing the same direction or differential of the motor speeds of the EDFs, the pitching direction and lateral direction movements of the wing are controlled.

[0043] Furthermore, a partition is provided between the inner wing and the outer wing, and the partition separates the wing surfaces of the inner wing and the outer wing.

[0044] Specifically, the outer wing and the inner wing can be fixedly connected by separate components, or can be made of the same component into two components with different cross-sections to reduce induced drag. The leading and trailing edges of the sectional airfoil of the outer wing are opposite to those of the inner wing.

[0045] Furthermore, a pair of X-shaped free rotors composed of rectangular strips for emergency rescue are installed on the top of the carriage of the flying car. The rotating shaft of the free rotor is near the overall center of gravity of the flying car, and the rotating shaft leads directly into the carriage interior.

[0046] Preferably, through aesthetic design, the ejection mechanism of the free rotor is hidden inside the vehicle body; due to size limitations, the rotor is designed as a pair and folded in two sections for easy storage;

[0047] When an emergency occurs and the control center determines that emergency measures must be taken, the automatic control system executes the command to eject the free rotor and immediately start working. Due to the high enough rotational speed and high blade efficiency, the upward vertical force generated is quite large. Even if the aircraft crashes, the lift generated by the autorotor can buffer the falling speed of the crashed aircraft, making the landing speed within a safe range, less than 3.5 meters per second, to protect the aircraft and the personnel or goods inside. The effectiveness of this device has been verified on the anti-tank low-altitude fighter jets already in service in our country. Preferably, for greater safety, the support joints of the free rotor adopt magnetic suspension bearings.

[0048] This combined wing system product includes an emergency rescue application scenario, using a free rotor (ROTO WING) to replace the life-saving parachute. The free rotor consists of two rectangular strips. Using the principle of generating a huge lift by locally accelerating the air flow velocity, a vertical force is generated in an emergency state to buffer the falling speed of the aircraft. Even in a stall, it will not crash and hit the ground. At most, only local structural deformation and damage will occur, but the safety of personnel and goods is protected, which is superior to the life-saving parachute.

[0049] Preferably, each free rotor is 700 cm long and 30 cm wide. Usually, it is hidden on both sides of the vehicle body. In an emergency, it is opened, and one piece on the left and one piece on the right are cross-combined into an X-shaped free rotor.

[0050] The present invention also provides an application method for a combined wing system based on distributed ducted fans, which is used for the flight of the combined wing system based on distributed ducted fans as described above, and includes:

[0051] When the flying car takes off vertically, rotate the front half wing of the wing from the vertical state 90° obliquely upward around the flap spanwise rotation axis to the horizontal state, that is, turn to the working state, and close the leading edge slat of the wing without opening it;

[0052] After the flying car ascends and hovers, when preparing to switch to horizontal cruise flight, in the constant altitude flight state of the EDF, rotate the combined wing system 90° forward around the hinge axis in the vertical direction so that the combined wing system is perpendicular to the longitudinal axis of the fuselage; slowly and smoothly rotate the trailing edge flap of the combined wing system together with the EDF 35° forward and downward from the vertical 90° state and hold for 5 - 10 seconds to accelerate the flying car forward; when reaching the stall speed, turn the trailing edge flap to the horizontal state, continue to accelerate, then open the leading edge slat, trim, and enter the cruise horizontal flight state;

[0053] After reaching the destination, close the leading edge slat, then decelerate and fly level. Gradually deflect the trailing edge flap 90° backward and downward so that the EDF is perpendicular to the ground and hover at the same altitude as the level flight altitude, reduce the thrust, and descend vertically smoothly. At the same time, rotate the front half wing of the wing from the vertical state 90° obliquely downward around the flap spanwise rotation axis to the vertical state, that is, turn to the storage state, and return to the ground (i.e., perform the opposite operations to takeoff, hover, and then level flight).

[0054] The present invention also provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, the steps of the application method for the combined wing system based on distributed ducted fans as described above are implemented.

[0055] The present invention also provides a computer device. The computer device includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, the steps of the application method for the combined wing system based on distributed ducted fans as described above are implemented.

[0056] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0057] The combined wing system based on distributed ducted fans provided by the present invention and its application method arrange distributed ducted fans (EDF) at the trailing edge flaps of the wing. When the EDF is operating, it guides the airflow to flow over the upper surface of the wing through an air suction method, generating negative pressure. During vertical takeoff, although the wing does not move forward, the wing will also generate induced lift. The resultant force is formed by the combination of the induced lift and the upward reaction force of the Newtonian force generated by the EDF jet, pushing the entire flying car to a high altitude. Moreover, a structure with an installation angle and reverse arrangement of the leading and trailing edges of the inner and outer wings is designed to further increase lift and reduce drag. At the same time, a high-lift airfoil is adopted to efficiently improve the lift-to-drag ratio and effectively enhance the flight efficiency. During takeoff and hovering, the spanwise direction of the EDF combined wing is parallel to the vehicle body's central axis, reducing the spanwise scale during takeoff. When transitioning to horizontal flight in the air, the EDF combined straight wing rotates around the vertical axis so that the wingspan is perpendicular to the vehicle body, ensuring high efficiency and stability during horizontal flight. Based on the same principle, combining the EDF with a planar annular wing forms a two-dimensional composite wing, which improves the lift coefficient and eliminates induced drag, having higher vertical takeoff and hovering efficiency and a wider range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] By reading the detailed description of the preferred embodiments below, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention.

[0059] In the drawings:

[0060] Figure 1 is a schematic structural diagram of a combined wing system based on distributed ducted fans according to the present invention;

[0061] Figure 2 is a configuration diagram of a combined wing system based on distributed ducted fans according to the present invention during the vertical takeoff and landing stage;

[0062] Figure 3 is a configuration diagram of a combined wing system based on distributed ducted fans according to the present invention during the horizontal flight stage;

[0063] Figure 4 is a planar configuration diagram of the combined ring wing according to the present invention;

[0064] Figure 5 is a side configuration cross-sectional view of the combined ring wing according to the present invention;

[0065] Figure 6 、 7 is a schematic structural diagram of a 20-person sightseeing flying saucer according to Embodiment 3 of the present invention;

[0066] Figures 8 - 10 is a physical model diagram of a car-plane using 4 groups of combined ring wings according to Embodiment 1 of the present invention;

[0067] Figures 11 - 13 Structural schematic diagrams of various states of the car-plane according to Embodiment 1 of the present invention;

[0068] Figure 14 Installation structure diagram of the free rotor according to an embodiment of the present invention;

[0069] Figure 15 Schematic diagram of the composition of a computer device according to an embodiment of the present invention.

[0070] The reference signs in the drawings are represented as:

[0071] 1, inner wing; 2, leading edge slat; 3, distributed ducted fan assembly, 31, ducted fan; 4, outer wing; 5, wing tip vortex generator; 6, hinge shaft; 7, partition; 8, connecting rod; 9, flap spanwise rotating shaft; 10, free rotor; 11, observation tower. Detailed implementation manners

[0072] Here, the exemplary embodiments will be described in detail, and the examples are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the present disclosure. On the contrary, they are merely examples of devices and products consistent with some aspects of the present disclosure as detailed in the appended claims.

[0073] The terms used in the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. The singular forms "a", "the" and "said" used in the present disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0074] It should be understood that although the terms first, second, third, etc. may be used in the present disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present disclosure, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "when" or "while" or "in response to determining".

[0075] The following further describes the embodiments of the present invention in detail with reference to the drawings.

[0076] Embodiment 1

[0077] This embodiment is a 3-ton vertical takeoff and landing passenger and cargo dual-purpose vehicle aircraft, powered by an extended-range hybrid electric system.

[0078] This is a large cargo / passenger vehicle aircraft that is air-land amphibious and has vertical takeoff and landing capabilities, constructed using an electric ducted fan combined wing system. The combined wing system is arranged on both sides of the flying vehicle. The wings symmetrically arranged on both sides of the flying vehicle include: an inner wing 1, an outer wing arranged in sequence along the direction from near to far from the cockpit, a leading-edge slat 2 and a trailing-edge flap arranged on the leading edge of the inner wing 1; a plurality of ducted fans 31 parallel to the aerodynamic chord and evenly spaced are installed on the trailing-edge flap and can deflect downward following the trailing-edge flap; the airfoil leading and trailing edges of the outer wing are opposite to those of the inner wing 1, and the trailing edge is in the front. Figure 2 The configuration of the aircraft during the vertical takeoff and landing phase is shown. Figure 3 The configuration of the aircraft during the horizontal flight phase is shown. Figure 1 The structural schematic diagram and working principle of the distributed electric ducted fan combined wing are shown. Existing typical flying vehicles (such as transition developed by Terrafugia Inc. in the United States and Air Car developed in Slovenia), they must drive to a regular airport for takeoff by taxiing. When taking off, a pair of aircraft wings with a very long wingspan hidden inside are first extended to become a fixed-wing aircraft, and then they accelerate, taxi, pull up, and take off on the airport runway according to the takeoff procedure of general aviation aircraft. They require a very long runway and site. They can drive on the ground like a normal car. But it is impossible to take off or land on the road or a helicopter landing site.

[0079] This embodiment is different from existing typical flying vehicles and can take off and land on any relatively flat small site, including open spaces in the city center, existing helicopter landing platforms, and even the rooftop platforms of large metropolitan high-rise buildings. When vertically taking off, only need to rotate the front part of the combined wing from the stowed state to the horizontal plane state, and keep the wingspan parallel to the vehicle body. There is no need to rotate the wing to a position perpendicular to the vehicle body at this stage. Because there is no speed moving forward or in other directions at this time. The wing itself has no aerodynamic force. The working principle of the ducted fan combined wing system determines that it has nothing to do with the orientation of the wing in the initial stage. The advantage is that the lateral (spanwise) dimension of the vehicle aircraft during takeoff is very short, and the requirements for the site are not high. It can take off on the road (permitted in the future) or any small stoppable site. When the aircraft vertically takes off, hovers, and is about to switch to cruise level flight, the wing orientation is switched in the air to become the fixed-wing aircraft configuration. Figures 11 - 13 The various states of the vehicle aircraft of this embodiment are shown.

[0080] The main parameters and flight performance of this vehicle aircraft are as follows:

[0081] The overall length of the aircraft is 6.94 meters; the width is 2.5 meters; the height is 2 meters. The average aerodynamic chord length of the wing is 1.25 meters, and the semi-wingspan (excluding the fuselage) is 6 meters.

[0082] The overall wingspan (including the fuselage) is 14.5 meters;

[0083] The aerodynamic chord length is 1.25 meters; the aspect ratio A = 11.6;

[0084] A partition 7 is provided between the inner wing 1 and the outer wing 4. A distributed ducted fan assembly 3 is installed on the trailing edge flap of the inner wing 1 (2 / 3 of the semi-wingspan). The distributed ducted fan assembly 3 includes 18 EDFs (ducted fans 31); the diameter of a single ducted fan 31 is φ25 cm and the height is 25 cm. The thrust of a single EDF is 25 kg; the power is 20 KW. A total of 38 EDFs are installed on the whole aircraft (36 of which are used as the main power source; 2 are used as control vector actuators, which can be finely adjusted but cannot be tilted 90°. The 2 control vector actuators are vertically upward and can perform synchronous or differential movements.

[0085] This car-plane is equipped with a total of 36 ducted fan engines. In addition, this car-plane does not install an aerodynamic control surface control system, but adopts a ducted fan thrust vector control system with faster response and more accurate control. A horizontal stabilizer and a vertical stabilizer are installed on the upper part of the tail. One EDF with a diameter of φ30 cm is installed on each of the left and right horizontal stabilizers and the vertical stabilizer. It is installed on the horizontal stabilizer and can be folded. When in use, the EDF moves outwards so that the slipstream does not spray onto the fuselage.

[0086] The length of the outer wing 4 is one-third of the semi-wingspan length (i.e., 2 meters).

[0087] The dimensions of the ducted fan 31 behind the car: diameter φ30 cm, thickness (height) 30 cm.

[0088] The outer wing 4 is in a small trapezoidal shape: the root-to-tip width ratio is 1:2 / 3.

[0089] The maximum takeoff weight Wo = 3200 kg; it can carry 8 passengers or carry 1000 kg of cargo;

[0090] The power plant adopts range-extended hybrid technology. The internal combustion engine uses products with high quality and good reliability. For example, two 380-horsepower engines of BMW B58. The generator and the motor should also be of high quality and high thrust-to-weight ratio. The energy density of the on-board battery is 300 Wh / Kg. The battery weight is used for charging, emergency backup, and leaving a 6% margin. When driving electrically in the urban area without turning on the internal combustion engine, it can fly 200 kilometers;

[0091] The fuel loaded in the aircraft is 271 kg; the battery is 49 kg;

[0092] The cruise speed is 360 km / h; the cruise altitude is 2500 meters; the total range is 1959 kilometers, or the flight time is 5.44 hours.

[0093] The driver's door can be lifted from the front window for entry (similar to a fighter jet); goods enter and exit through the rear trunk door.

[0094] At the outer end of the outer wing 4, a wingtip vortex generator 5 is provided. At the trailing edge of the inner wing 1, a trailing edge flap for lift augmentation and drag reduction is provided. On the trailing edge flap, a flap spanwise rotating shaft 9 along the wingspan direction is provided, and the flap spanwise rotating shaft 9 penetrates through the inner wing 1 and the outer wing 4; the leading edge slat 2 can rotate downward. At the connection between the wingspan of the wing and the main body beam of the car-plane, a vertical hinge shaft 6 is provided, and the wing can rotate and fold around the hinge shaft 6. Near the inner wing corner of the EDF combined wing, another rotating shaft is provided. The hinge shaft 6 and the other rotating shaft form a linkage mechanism through a connecting rod 8, and the linkage mechanism connects the wing and the main body beam of the vehicle body to enhance the stability and reliability of the wing rotation.

[0095] This product includes an emergency rescue application scenario (see Figure 14 shown), which uses a free rotor 10 (ROTOWING) to replace the traditional rescue parachute. The free rotor 10 is composed of two rectangular strips. Using the principle of generating a huge lift by locally accelerating the air flow velocity, a vertical force is generated in the emergency state to buffer the falling speed of the aircraft. Even if it stalls, it will not crash and hit the ground. At most, only the local structure is deformed and damaged, protecting the safety of personnel and goods, which is superior to the rescue parachute. Each piece of the free rotor 10 is 700 cm long and 30 cm wide, usually hidden on both sides of the vehicle body and opened in an emergency, with one piece on each side crossing to form an X-shaped wing.

[0096] Embodiment 2

[0097] This embodiment is a four-ring wing business flying car for passengers.

[0098] This is the application of a distributed ducted fan annular combined wing to a small and medium-sized car-plane. As Figure 4 and Figure 5 shown.

[0099] The difference between this embodiment and Embodiment 1 is that this embodiment combines a ducted fan and a planar ring wing (ring wing). A plurality of ducted fans 31 are vertically arrayed evenly at equal distances along the circumference, and are connected end to end to form a combined ring wing. The combined ring wing is applied to the planar ring wing, and the outer circle of the combined ring wing is the leading edge of the planar ring wing. Especially in the vertical takeoff and landing stage, when the EDF works, it attracts the surrounding air flow into the duct and discharges it from the lower nozzle, generating a powerful Newtonian reaction force.

[0100] Since the air flow velocity around the duct is very high, close to 100 meters per second, any lifting surface with an airfoil placed in it will generate induced lift. Someone has placed a straight wing in front of the EDF intake, and it has been proven to be very effective.

[0101] The concept of this embodiment is to arrange the EDFs in a group of closed circular configurations with the air inlet facing upward. The air inlet is close to the EDF ring at the same time, and a closed lifting surface is also placed in a circle close to the air inlet with the leading edge facing outward, and beneficial effects similar to or even better than those of placing a straight wing can also be obtained. Figure 4 , Figure 5 It expresses the implementation method of the above concept, and the resulting structure is a closed assembly that has no head or tail and is connected end to end. Theoretically, this structure is a two-dimensional airfoil with an aspect ratio equal to infinity. Since there is no wingtip vortex, no downwash is generated on the annular wing, and the three-dimensional wing has the same performance as the two-dimensional wing. Therefore, when calculating the lift characteristics of this combined annular wing, the two-dimensional lift line slope can be used. Usually, wings have a finite aspect ratio, and the three-dimensional effect of the wingtip vortex reduces the three-dimensional lift line slope significantly. The smaller the wingspan, the smaller the lift and the greater the induced drag. At a large angle of attack, the airflow is not easy to separate and stall when passing through the lift ring. Another prominent advantage of this combined annular wing is that there is no lift loss, but the drag disappears: there is no induced drag, only zero-lift drag. Due to the axisymmetric characteristics of the ring, the sum in the horizontal plane is zero. Because of symmetry, they cancel each other out. Thus, the aerodynamic efficiency of this circular ring structure is very high. Another advantage is that axisymmetric objects are easy to process, the cost is reduced, which is beneficial to product standardization. Different specifications of products can be manufactured according to different sizes and different EDF powers for manufacturers to choose from, improving production efficiency.

[0102] This embodiment can upgrade the power system of the applicant's previous product using tilt rotors. The body structure and appearance remain unchanged, only replacing the original tilt rotors with 4 groups of combined annular wings of the same size and the same power (as Figures 8 - 10 shown), and the process is simple.

[0103] The overall dimensions and performance of this embodiment are as follows:

[0104] Body: length 5 meters; width 1.8 meters; maximum height inside the body 1.5 meters;

[0105] Maximum takeoff weight 650 kg; pure electric power propulsion;

[0106] Battery energy density 300 WH / kg;

[0107] The percentage of the total battery weight in the total takeoff weight is 20%, that is, 130 kg.

[0108] Cruise speed 350 km / h; cruise altitude 3000 m;

[0109] Vertical takeoff climb rate 10 m / s; range 500 km.

[0110] Combined ring wing parameters: The diameter of the primitive EDF is φ25 cm; single unit power = 27.61 kW; single unit thrust = 45.98 kg;

[0111] The method for constructing the combined ring wing of this embodiment is as follows:

[0112] (1) EDF power ring: 8 EDFs are evenly arranged along a 0.5-meter circumference line to form an EDF power ring with an inner diameter of φ0.5 m and an outer diameter of φ1 m. Then, a closed ring wing with a high-lift airfoil section is installed outside the EDF power ring. The leading edge of the airfoil section of the closed ring wing faces outward, and there is an installation angle of 10° between the aerodynamic chord of the airfoil section and the horizontal plane. Due to the use of a large camber airfoil, the zero-lift angle is -7.8°. The designed two-dimensional lift line slope is 0.1323. The area of the horizontal projection plane of the ring wing is 4.1234 square meters.

[0113] To achieve the design parameters, after calculation, the maximum wind speed generated by the ducted fan rotating at high speed is 61.21 m / s. Assuming that the average induced air flow velocity on the upper surface of the closed ring wing by the EDF is only 60% of the ducted fan wind speed, that is, 36.73 m / s, the combined ring wing will generate an induced lift of 1349 kg. The Newtonian force generated by 8 EDFs is: 8 × 45.98 = 367.84 kg. The total vertical lift provided by the combined ring wing is 1716.84 kg. It can be considered that this is the maximum lift that the combined ring wing can provide. The outer diameter of this circular wing is 1.25 m. If the size is reduced, such as using a small EDF of 19.5 cm, the maximum lift can be roughly estimated to be about 1044.53 kg. It can be seen from this that the aerodynamic efficiency of the circular wing device in this embodiment is relatively high: the proportion of induced lift reaches 78.57%; while the proportion of Newtonian force is 21.43%. In actual use, the maximum power does not have to be used, but there is a margin, and the rated power or a lower power is used. The power is controlled by adjusting the motor speed of the EDF.

[0114] Taking the combined ring wing as the basic unit, based on knowing the mechanical properties of the basic unit, new aircraft with various performances can be designed. For example, smaller-sized EDFs can be used to form a combined ring wing with a smaller diameter. For this embodiment, the diameter of φ1.25 m is relatively large. The diameter of the EDF can be reduced to about φ15 cm, so that the total lift of a single ring is about 250 kg, and a group of 4 has a total lift of 1000 kg. Even using only one combined component with a diameter of φ1 m can meet the requirements of a flying car for only two people.

[0115] Embodiment 3

[0116] This embodiment is a sightseeing flying saucer for 20 people. The similarities between this embodiment and Embodiment 2 are that a combined ring wing is also used, and multiple ducted fans 31 are vertically arrayed at equal distances along the circumference in a circumferential direction, connected end to end to form a combined ring wing. The combined ring wing is applied to a planar annular wing, and the outer circle of the combined ring wing is the leading edge of the planar annular wing. The difference between this embodiment and Embodiment 2 is that in this embodiment, the combined ring wing is not applied to a car-plane, but to a flying saucer configuration.

[0117] As Figure 6 , shown in Figure 7, the maximum outer diameter of the flying saucer is 8 meters, it can carry 20 passengers, and the maximum take-off weight is 8000 kg.

[0118] Six EDF combined ring wings are installed at equal distances around the flying saucer, and the diameter of the basic EDF is φ20cm. The power of a single unit is 15.4kW, and the total power is 739kW. It looks like a cowboy hat, with a circular ring as the brim, and there is a cylindrical sightseeing tower 11 in the middle. There are 20 observation windows around the ring of the sightseeing tower 11. There are 4 buffer-function struts at the bottom of the brim to support the flying saucer on the ground. After take-off, the struts retract and hide. This sightseeing flying saucer is purely electrically driven. The endurance time is 2 hours each time. According to the needs of culture and tourism, a series of products can be constructed, which can carry up to 100 people at most and as few as 3 - 5 people at least.

[0119] The embodiment of the present invention also provides a computer device, Figure 15 which is a schematic structural diagram of a computer device provided by the embodiment of the present invention; refer to the attached drawings Figure 15 shown. This computer device includes: an input device 23, an output device 24, a memory 22, and a processor 21; the memory 22 is used to store one or more programs; when the one or more programs are executed by the one or more processors 21, the one or more processors 21 implement the application method of the combined wing system based on distributed ducted fans as provided in the above embodiment; wherein the input device 23, the output device 24, the memory 22, and the processor 21 can be connected through a bus or other means, Figure 15 taking connection through a bus as an example.

[0120] The memory 22, as a computable device-readable and writable storage medium, can be used to store software programs and computer-executable programs, such as the program instructions corresponding to the application method of the combined wing system based on distributed ducted fans as described in the embodiments of the present invention. The memory 22 may mainly include a program storage area and a data storage area. Among them, the program storage area can store an operating system and application programs required for at least one function; the data storage area can store data created according to the use of the device, etc. In addition, the memory 22 may include high-speed random access memory and may also include non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other non-volatile solid-state storage devices. In some instances, the memory 22 may further include a memory remotely set relative to the processor 21, and these remote memories can be connected to the device through a network. Examples of the above network include but are not limited to the Internet, an enterprise intranet, a local area network, a mobile communication network, and combinations thereof.

[0121] The input device 23 can be used to receive input digital or character information and generate key signal inputs related to the user settings and function control of the device; the output device 24 may include display devices such as a display screen.

[0122] The processor 21 executes various functional applications and data processing of the device by running the software programs, instructions, and modules stored in the memory 22, that is, implements the above-mentioned application method of the combined wing system based on distributed ducted fans.

[0123] The above-provided computer device can be used to execute the application method of the combined wing system based on distributed ducted fans provided in the above embodiments, and has corresponding functions and beneficial effects.

[0124] An embodiment of the present invention also provides a storage medium containing computer-executable instructions, which are used to execute the application method of the combined wing system based on distributed ducted fans provided in the above embodiment when executed by a computer processor. The storage medium is any of various types of memory devices or storage devices, including: installation media such as CD-ROMs, floppy disks or magnetic tape devices; computer system memories or random access memories such as DRAM, DDRRAM, SRAM, EDORAM, Rambus RAM, etc.; non-volatile memories such as flash memories, magnetic media (such as hard disks or optical storage); registers or other similar types of memory components, etc.; the storage medium may also include other types of memories or combinations thereof; additionally, the storage medium may be located in a first computer system in which the program is executed, or may be located in a different second computer system, and the second computer system is connected to the first computer system through a network (such as the Internet); the second computer system may provide program instructions to the first computer for execution. The storage medium includes two or more storage media that may reside in different locations (such as in different computer systems connected through a network). The storage medium may store program instructions (such as specifically implemented as a computer program) executable by one or more processors.

[0125] Of course, the computer-executable instructions of a storage medium containing computer-executable instructions provided by an embodiment of the present invention are not limited to the application method of the combined wing system based on distributed ducted fans described in the above embodiment, and may also execute related operations in the application method of the combined wing system based on distributed ducted fans provided by any embodiment of the present invention.

[0126] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present invention.

[0127] The above are only the preferred embodiments of the present invention and are not used to limit the present invention; for those skilled in the art, the present invention may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A combined wing system based on distributed ducted fans, arranged on both sides of a flying car, characterized in that: include: The wings are symmetrical on both sides of the flying car, and the wings include an inner wing and an outer wing arranged in sequence from near to far from the cockpit, and a leading edge slat and a trailing edge flap arranged on the inner wing; the trailing edge flap is equipped with a plurality of ducted fans parallel to the aerodynamic chord at uniform intervals and capable of being deflected downward by the trailing edge flap; the leading and trailing edges of the airfoil of the outer wing are opposite to those of the inner wing, and the trailing edge is arranged in front; A plurality of the ducted fans are evenly and equidistantly distributed in a vertical array along the circumference of a circle, connected end to end to form a combined ring wing, the combined ring wing is applied to a plane ring-shaped wing, and the outer circle of the combined ring wing is the leading edge of the plane ring-shaped wing; A vertical hinge axis is provided at the connection between the span direction of the wing and the main beam of the flying car body, and the wing can be rotated and folded around the hinge axis; The trailing edge flap is provided with a flap span-wise rotation axis along the wingspan direction, and the flap span-wise rotation axis passes through the inner wing and the outer wing; a leading edge slat is provided near the wing tip at the leading edge of the wing, and the front half of the wing can rotate around the flap span-wise rotation axis; Two large-diameter ducted fans are installed at the rear of the flying car as control vector actuators, and the large-diameter ducted fans are arranged vertically upward; A partition is provided between the inner wing and the outer wing, and the partition separates the wing surfaces of the inner wing and the outer wing; A pair of X-shaped free rotors composed of rectangular strips for emergency rescue are installed on the top of the flying car's cabin. The rotating shaft of the free rotor is located near the center of gravity of the flying car, and the rotating shaft directly passes through the interior of the cabin.

2. An application method of a combined wing system based on a distributed ducted fan, used for the flight of the combined wing system based on a distributed ducted fan as claimed in claim 1, characterized in that: include: When the flying car takes off vertically, the front half of the wing is rotated 90° upward around the flap span axis from a vertical state to a horizontal state, that is, to a working state, and the leading edge slats of the wing are closed and not opened; After the flying car takes off and hovers, and is ready to switch to horizontal cruising flight, the ducted fan rotates the combined wing system 90° forward around the vertical hinge axis in the fixed altitude flight state, so that the combined wing system and the longitudinal axis of the fuselage are perpendicular; the trailing edge flaps of the combined wing system and the ducted fan are slowly and steadily rotated from the vertical 90° state to the front and bottom 35°, and maintained for 5-10 seconds, so that the flying car accelerates forward; when the stall speed is reached, the trailing edge flaps are turned to the horizontal state, and the acceleration is continued, and then the leading edge slats are opened, the trim is balanced, and the flying car enters the cruising horizontal flight state; After arriving at the destination, close the leading edge slats, then slow down, fly level, and gradually deflect the trailing edge flaps 90° rearward and downward so that the ducted fan is perpendicular to the ground and hovers at the same altitude as the level flight altitude, reducing thrust and descending vertically smoothly. At the same time, rotate the front half of the wing from a vertical state around the flap span axis 90° diagonally downward to a vertical state, that is, turn it to the stowed state, and return to the ground.

3. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by the processor, the steps of the application method of the combined wing system based on the distributed ducted fan described in claim 2 are implemented.

4. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the application method of the combined wing system based on the distributed ducted fan as described in claim 2 are implemented.

Images