Distributed ducted fan power wing electric propulsion system

Abstract

The invention discloses a distributed ducted fan power wing electric propulsion system. The distributed ducted fan power wing electric propulsion system comprises wings and tilting mechanisms. Ducted fans are arranged on the upper surfaces of the wings, and the multiple ducted fans are separately arranged in the extension direction of the wings; the tilting mechanism is used for adjusting the tilting angles of the multiple ducted fans, so that the multiple ducted fans at least have the working state of providing vertical lift force and horizontal thrust force; wherein the multiple ducted fans have the same ducted performance, and the distribution parameter XYZ of the ducted fans on the wings, the installation angle a of the ducted wings and other parameters all have specific requirements; after the arrangement mode is adopted, the propelling system can meet different flight working condition requirements of vertical takeoff, tilting transition and cruising flight of the eVTOL aircraft; and through the integrated design of the wings and the ducts, the ducts and the trailing edge flaps form a fused flap duct component, and the propelling performance and aerodynamic efficiency of the novel propelling system are improved through the pneumatic propelling coupling effect and the duct suction effect.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft propulsion systems, and in particular to a distributed ducted fan powered wing electric propulsion system. Background Art

[0002] Electric vertical take-off and landing aircraft (eVTOL) is a future urban aerial general-purpose aircraft that is intelligent, low-noise, low-cost, green and highly safe. The current eVTOL aircraft is updated and iterated rapidly, and a variety of configurations have been developed, but it still faces problems such as short endurance, low speed, and small load capacity. The multi-rotor configuration eVTOL uses multiple distributed propellers as the power system, and relies on propeller pull to overcome gravity during the overall flight process. On the one hand, this type of power system greatly limits the flight speed of the aircraft, and on the other hand, it leads to high power consumption and low flight efficiency; therefore, this configuration power system cannot meet the needs of long-range and high-speed general aviation flights between cities, and cannot form product applications. The composite wing configuration eVTOL adopts two redundant power designs: the vertical take-off rotor power system and the cruise rotor power system, but the redundant power system design will increase the structural mass, increase the cruising flight resistance, and insufficient flight efficiency. Therefore, the design of the two power systems also has its shortcomings. The power system of the current new generation eVTOL is a tilt-rotor, which retains the advantage of high force efficiency of the rotor in the vertical take-off stage, and integrates the advantage of efficient cruising flight of the composite wing in the cruise flight stage. A tilt-rotor electric propulsion system is designed, using only one set of power unit to achieve the multiple working conditions of vertical take-off, tilting and cruise flight.

[0003] Distributed tilt-ducted electric vertical take-off and landing aircraft is a representative development direction of the new generation of eVTOL. It adopts a distributed duct tilt power system design. On the one hand, it realizes the vertical take-off and landing function. On the other hand, it uses the boundary layer design and coupling effect of the wing and duct during cruising flight to enable it to have high-speed and efficient cruising flight, meeting the needs of long-range and high-speed general aviation flights between cities. Therefore, the development of its new high-efficiency and long-range electric propulsion system has become one of the important breakthrough technologies for the new generation of eVTOL aircraft.

[0004] However, the complex physical processes and coupling mechanisms within the system, such as complex flow field interactions, structural mechanical responses, and flight control coupling, have not yet been fully, deeply, and systematically explained and explored. Summary of the invention

[0005] The purpose of the present invention is to provide a distributed ducted fan powered wing electric propulsion system to solve the problems of low flight efficiency, short endurance, low speed, small load capacity, and inability to meet the needs of long-range inter-city and high-speed general aviation flights in existing eVTOLs.

[0006] In order to solve the above technical problems, the present invention provides a distributed ducted fan powered wing electric propulsion system, including a wing and a tilt mechanism; the wing is provided with a ducted fan, and a plurality of the ducted fans are arranged separately along the span direction of the wing; the ducted wing installation angle a between the ducted fan and the wing is 83°~90°; the distance between the inlet cross section of the ducted fan and the leading edge point of the wing in the incoming flow direction is X=0.4c~0.8c; the distance between the center of the inlet axis of the ducted fan and the leading edge point of the wing in the vertical direction is Y=0.5R~1.5R; the distance between the center of the axis of adjacent ducted fans is Z=1.2R~3R, and Z<0.3L d The distance between the axis center of the ducted fan closest to the root of the wing and the root of the wing is Z0 = 0.05Ld ~ 0.15L d ; Wherein, c is the root chord length of the wing, R is the outer dimension of the ducted fan, L d is the wingspan length of the wing; the tilt mechanism is used to synchronously adjust the tilt angles of the multiple ducted fans so that the multiple ducted fans at least have the working state of providing vertical lift and horizontal thrust.

[0007] In one embodiment, the tilting mechanism includes a driving motor, a gear set and a rotating shaft; the driving motor is used to drive the gear set to rotate; the rotation of the gear set is used to drive the rotating shaft to rotate; a plurality of connecting parts are provided on the rotating shaft, and the plurality of connecting parts are arranged and separated along the axial direction of the rotating shaft, and the plurality of connecting parts are respectively connected to the ducted fan, and the rotation of the rotating shaft is used to drive the ducted fan to tilt.

[0008] In one of the embodiments, the flaps of the wing are connected to the rotating shaft so that the flaps and the ducted fan become an integrated structure that tilts synchronously.

[0009] In one embodiment, the wing includes root ribs, middle ribs, end ribs, a spar and a foam shell; from the root of the wing to the wingtip of the wing, the root ribs, the middle ribs and the end ribs are separated and arranged relatively in sequence; the spar passes through the root ribs, the middle ribs and the end ribs; the foam shell covers the outer surface of the wing.

[0010] In one of the embodiments, a positioning rib is provided between the end rib and the middle rib, and a rotatable shaft is connected between the positioning rib and the end rib.

[0011] In one embodiment, the distributed ducted fan powered wing electric propulsion system supplies power to a plurality of the ducted fans in parallel.

[0012] The beneficial effects of the present invention are as follows:

[0013] As for the aerodynamic-propulsion coupling characteristics of the distributed ducted fan powered wing electric propulsion system of the present invention, it has excellent aerodynamic and propulsion characteristics during high-speed cruising flight. The internal and external airflows of the propulsion system are strongly coupled with the airflow on the wing surface, and the performance of the duct is in the best state under high-speed flight conditions. Due to the suction effect of the duct further accelerating the airflow on the upper surface of the wing and the coupling effect of the duct wake on the underwash airflow of the wing, the lift-to-drag ratio of the wing and the static thrust of the duct can be greatly increased, thereby reducing cruising power consumption and meeting the needs of long-range and high-speed general aviation flights between cities.

[0014] For the distributed design of the distributed ducted fan power wing electric propulsion system of the present invention, there are different schemes for the distribution design of the ducted fan. There are different designs for the distribution of the ducted fan unit on the upper surface of the wing trailing edge, including: the chord-wise distance X between the ducted fan inlet and the wing leading edge point, the vertical distance Y between the ducted fan axis and the upper surface of the wing, and the spacing distance Z between the ducted fans. Through calculation and analysis, the present invention selects a set of better XYZ distribution parameters as the distribution parameter device of the ducted fan, and on this basis, the ducted fan and flap are integrated into a design.

[0015] For the fused flaps and ducted fans of the distributed ducted fan powered wing electric propulsion system of the present invention, the system performance is improved and optimized by integrating the design of the distributed duct components and utilizing the aerodynamic propulsion coupling effect mechanism. A group of distributed duct components is composed of two or more ducted fan units, and the duct units of the same component have the same duct performance, rotation direction, distribution position of the duct on the wing, installation angle of the duct and the wing, and other parameters. The wing and the distributed duct components are designed in an integrated manner so that the duct and the trailing edge flap form a fused flap duct component. By utilizing the aerodynamic propulsion coupling effect and the duct suction effect, the propulsion performance and aerodynamic efficiency of the new propulsion system are improved.

[0016] For the tilt control of the distributed ducted fan powered wing electric propulsion system of the present invention, an integrated tilt control design is adopted. The fused flap duct assembly is connected to the rotating shaft through a connecting piece. The electronic control system is responsible for providing power and control signals to the driving unit of the tilt mechanism. The driving unit drives the rotating shaft to rotate, realizes the tilt of the fused flap duct assembly, and realizes the power group state switching, so that the propulsion system can meet the different flight conditions of eVTOL flight.

[0017] Therefore, after adopting the above-mentioned setting method, the propulsion system will meet the different flight conditions of vertical take-off, tilt transition and cruising flight of the eVTOL aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the implementation mode will be briefly introduced below. Obviously, the drawings described below are only some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 is a schematic diagram of an external structure provided by an embodiment of the present invention;

[0020] Figure 2 It is a schematic diagram of the internal structure provided by an embodiment of the present invention;

[0021] Figure 3 The ducted fan layout provided by the embodiment of the present invention is Figure 1 ;

[0022] Figure 4 The ducted fan layout provided by the embodiment of the present invention is Figure 2 ;

[0023] Figure 5 The ducted fan layout provided by the embodiment of the present invention is Figure 3 ;

[0024] Figure 6 The ducted fan tilt state provided by the embodiment of the present invention Figure 1 ;

[0025] Figure 7 It is a diagram of the tilting state of the ducted fan provided by an embodiment of the present invention.

[0026] The reference numerals are as follows:

[0027] 10. Wing; 11. Ducted fan; 12. Root rib; 13. Middle rib; 14. End rib; 15. Spar; 16. Foam shell; 17. Positioning rib; 18. Flaps;

[0028] 20. Tilt mechanism; 21. Drive motor; 22. Gear set; 23. Rotating shaft; 24. Connecting piece. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0030] The present invention provides a distributed ducted fan 11 power wing electric propulsion system, which is implemented as follows: Figure 1 and Figure 2 As shown, it includes a wing 10 and a tilt mechanism 20.

[0031] Regarding the wing 10, Figures 1 to 7As shown, the wing 10 is provided with a ducted fan 11, and a plurality of ducted fans 11 are arranged separately along the span direction of the wing 10; the ducted wing installation angle a between the ducted fan 11 and the wing 10 is 83° to 90°; the distance between the inlet cross section of the ducted fan 11 and the leading edge point of the wing 10 in the incoming flow direction is X=0.4c to 0.8c; the distance between the inlet axis center of the ducted fan 11 and the leading edge point of the wing 10 in the vertical direction is Y=0.5R to 1.5R; the axis center distance between adjacent ducted fans 11 is Z=1.2R to 3R, and Z<0.3L d The ducted fan 11 closest to the root of the wing 10 has a distance between its axis center and the root of the wing 10 of Z0 = 0.05Ld ~ 0.15L d Wherein, c is the root chord length of the wing 10, R is the outer dimension of the ducted fan 11, L d is the wingspan length of the wing 10.

[0032] Specifically, this embodiment adopts four ducted fans 11 arranged on the wing 10. The four ducted fans 11 are distributed on the upper surface of the wing 10 near the trailing edge. The four ducted fans 11 have the same duct performance, rotation direction, duct distribution parameters XYZ on the wing 10, ducted wing installation angle a and other parameters. The specific distribution parameters are shown in Table 1.

[0033]

[0034] In addition, if Figure 1 and Figure 2 As shown, in this embodiment, the wing 10 includes a root rib 12, a middle rib 13, an end rib 14, a spar 15 and a foam shell 16; from the root of the wing 10 to the wingtip of the wing 10, the root rib 12, the middle rib 13 and the end rib 14 are separated and arranged relatively in sequence; the spar 15 passes through the root rib 12, the middle rib 13 and the end rib 14; the foam shell 16 covers the outer surface of the wing 10.

[0035] In addition, a positioning rib 17 is provided between the end rib 14 and the middle rib 13 , and a rotatable shaft 23 is connected between the positioning rib 17 and the end rib 14 , thereby achieving installation and fixation of the shaft 23 .

[0036] Regarding the tilt mechanism 20, the tilt mechanism 20 is used to synchronously adjust the tilt angles of the plurality of ducted fans 11 so that the plurality of ducted fans 11 at least have a working state of providing vertical lift and horizontal thrust. To achieve this function, Figure 2As shown, this embodiment provides a tilting mechanism 20 including a driving motor 21, a gear set 22 and a rotating shaft 23; the driving motor 21 is used to drive the gear set 22 to rotate; the rotation of the gear set 22 is used to drive the rotating shaft 23 to rotate; a plurality of connecting members 24 are provided on the rotating shaft 23, and the plurality of connecting members 24 are arranged and separated along the axial direction of the rotating shaft 23, and the plurality of connecting members 24 are respectively connected to the ducted fan 11, and the rotation of the rotating shaft 23 is used to drive the ducted fan 11 to tilt.

[0037] Furthermore, in order to avoid interference between the ducted fan 11 and the wing 10 during the tilting process, this embodiment also arranges the flap 18 of the wing 10 to be connected to the rotating shaft 23, so that the flap 18 and the ducted fan 11 form an integrated structure that tilts synchronously, ensuring that the two can always maintain a constant relative position and preventing interference from occurring.

[0038] Furthermore, since the ducted fan 11 has high voltage specifications, different voltage values ​​will seriously affect the performance of the motor. Therefore, this embodiment sets a distributed ducted fan power wing electric propulsion system to supply power to multiple ducted fans 11 in parallel, so that the working voltages of multiple ducted fans 11 remain consistent, and then the circuit is connected in series with the battery, that is, a ducted fan 11 is connected to an electronic speed regulator alone, and then connected to a power supply, and then a number of such single ducted circuits are connected in parallel to form a distributed ducted circuit.

[0039] It should also be supplemented that the present invention mainly uses carbon fiber to make a wing beam and rib frame structure to resist lateral bending deformation and torsional deformation of the wing 10; the wing 10 uses foam hot wire processing to maintain its shape to bear the aerodynamic load of the wing 10; the main structure of the wing 10 is formed by composite processing of the foam shell 16 and the carbon fiber frame structure. For the tilt mechanism 20, an integrated shaft 23 tilt design is adopted, which is driven by a drive motor 21 and a gear set 22, and is divided into an external section and an internal installation section; in the external section of the tilt mechanism 20, the ducted fan 11 is connected to the shaft 23 and the flap 18 through a connector 24, so that the ducted fan 11 and the flap 18 form a structural integration, and one end of the shaft 23 is fixed to the rib of the wing 10 through a bearing to reduce the deflection deformation of the mechanism, and then the shaft 23 is driven by the drive motor 21 to rotate to achieve the tilt of multiple ducted fans 11; in the internal installation section of the tilt mechanism 20, the other end of the shaft 23 is fixed to the installation platform through a bearing seat, and the shaft 23 is connected to the drive motor 21 by gear meshing. The drive motor 21 drives the gear set 22 to rotate and drive the shaft 23 to rotate, thereby achieving the tilt of the ducted fan 11. The wiring channel of the electric control system and the space for installing the electric control steering gear are designed inside the wing 10.

[0040] Moreover, the present invention studies the influence of the distribution design of the ducted fan 11 on the wing 10 on the performance of the electric propulsion system, including the influence of the chord-wise distribution, span-wise distribution and longitudinal distribution position of the ducted fan 11 on the upper surface of the wing 10 on the aerodynamic performance and propulsion performance of the system. By exploring and selecting a set of optimal duct distribution parameters, the ducted fan 11 and the flap 18 are integrated. In addition, the influence of the suction effect coupling of the inlet flow field between the ducted fan 11 and the ducted fan 11 on the duct performance is also explored; the influence of the aerodynamic propulsion coupling of the inlet flow field of the ducted fan 11 and the flow field on the surface of the wing 10 on the aerodynamic performance and ducted propulsion performance of the wing 10; the suction effect of the inlet of the ducted fan 11 on the suppression of flow separation of the wing 10 and the lift-increasing effect, etc. By exploring the coupling effect and deep physical mechanism of the distributed ducted power wing configuration, the integrated design and optimization of the ducted fan 11 and the flap 18, the boundary layer suction technology design, the aerodynamic propulsion coupling effect design, etc., are carried out to achieve the goal of improving the performance of the new electric propulsion system.

[0041] The present invention proposes a new electric propulsion system design that combines the dynamic characteristics of the ducted fan 11 with the aerodynamic characteristics of the wing 10 through research. By exploring the coupling effect between the two, the optimized design is carried out according to the mechanism inspiration to improve the aerodynamic performance and propulsion performance of the combined electric propulsion system. Among them, multiple ducted fans 11 on the same wing 10 have the same ducted performance and distribution parameters; the wing 10 and the ducted fan 11 are designed as an integrated unit, so that the ducted fan 11 and the flap 18 form a fused flap ducted component, and the propulsion performance and aerodynamic efficiency of the new propulsion system are improved by utilizing the aerodynamic propulsion coupling effect and the ducted suction effect; and the fused flap ducted component adopts an integrated tilt control design, the electric control system provides power and control signals, and the drive unit drives the shaft 23 to rotate, so as to realize the tilt of the fused flap ducted component, so that the propulsion system meets the different flight conditions of eVTOL flight.

[0042] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A distributed ducted fan powered wing electric propulsion system, characterized in that: Including wings and tilt mechanism; The wing is provided with a ducted fan, and a plurality of the ducted fans are arranged separately and in an array along the span direction of the wing; The ducted wing installation angle a between the ducted fan and the wing is 83° to 90°; The distance between the inlet cross section of the ducted fan and the leading edge point of the wing in the incoming flow direction is X=0.4c-0.8c; The distance between the center of the inlet axis of the ducted fan and the leading edge of the wing in the vertical direction is Y=0.5R~1.5R; The center distance between the axes of adjacent ducted fans is Z=1.2R~3R, and Z<0.3L d ; The distance between the axis center of the ducted fan closest to the root of the wing and the root of the wing is Z0 = 0.05Ld ~ 0.15L d ; Wherein, c is the root chord length of the wing, R is the outer dimension of the ducted fan, L d is the wingspan length of the wing; The tilt mechanism is used to synchronously adjust the tilt angles of the multiple ducted fans so that the multiple ducted fans can at least provide vertical lift and horizontal thrust.

2. The distributed ducted fan powered wing electric propulsion system according to claim 1, characterized in that: The tilting mechanism comprises a driving motor, a gear set and a rotating shaft; The driving motor is used to drive the gear set to rotate; The rotation of the gear set is used to drive the rotating shaft to rotate; A plurality of connecting members are provided on the rotating shaft, and the plurality of connecting members are arranged separately along the axial direction of the rotating shaft. The plurality of connecting members are respectively connected to the ducted fans, and the rotation of the rotating shaft is used to drive the ducted fans to tilt.

3. The distributed ducted fan powered wing electric propulsion system according to claim 2, characterized in that: The flaps of the wing are connected to the rotating shaft so that the flaps and the ducted fan form an integrated structure that tilts synchronously.

4. The distributed ducted fan powered wing electric propulsion system according to claim 2, characterized in that: The wing comprises a root rib, a middle rib, an end rib, a spar and a foam shell; From the root of the wing to the wingtip of the wing, the root rib, the middle rib and the end rib are sequentially separated and arranged relatively; The spar passes through the root rib, the middle rib and the end rib; The foam shell covers the outer surface of the wing.

5. The distributed ducted fan powered wing electric propulsion system according to claim 4, characterized in that: A positioning rib is provided between the end rib and the middle rib, and a rotatable shaft is connected between the positioning rib and the end rib.

6. The distributed ducted fan powered wing electric propulsion system according to claim 1, characterized in that: The distributed ducted fan power wing electric propulsion system supplies power to multiple ducted fans in parallel.

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