A distributed ducted fan powered wing electric propulsion system

Abstract

The present invention discloses a distributed ducted fan powered wing electric propulsion system, comprising a wing and a tilt mechanism; a ducted fan is provided on the upper surface of the wing, and a plurality of ducted fans are arranged separately along the span direction of the wing; the tilt mechanism is used to adjust the tilt angles of the plurality of ducted fans so that the plurality of ducted fans are at least capable of providing a working state of providing vertical lift and horizontal thrust; wherein the plurality of ducted fans have the same ducted performance, and the distribution parameters XYZ of the ducted fans on the wing, the ducted wing installation angle a and other parameters all have specific requirements; after adopting this setting method, the propulsion system will meet the different flight conditions requirements of the eVTOL aircraft, such as vertical take-off, tilt transition and cruising flight; and through the integrated design of the wing and the duct, the duct and the trailing edge flap form a fused flap duct component, and by utilizing the aerodynamic propulsion coupling effect and the ducted suction effect, the propulsion performance and aerodynamic efficiency of the new propulsion system are improved.

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 (eVTOL) aircraft are future general-purpose urban aerial vehicles that are intelligent, low-noise, low-cost, environmentally friendly, and highly safe. Current eVTOL aircraft are rapidly updated and have developed a variety of configurations, but they still face problems such as short flight range, low speed, and small payload. Multi-rotor eVTOL uses multiple distributed propellers as its power system, relying on propeller pull to overcome gravity during the entire 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 intercity flights and cannot form a product application. Composite wing eVTOL uses two redundant power designs: a vertical rotor power system and a cruise rotor power system. However, the redundant power system design will increase the structural mass, increase the cruise flight resistance, and lack of flight efficiency. Therefore, the design of two power systems also has its shortcomings. The current power system of the new generation of eVTOL is a tilt-rotor, which retains the advantage of high force efficiency of the rotor in the vertical take-off phase, and integrates the advantage of efficient cruising flight of the composite wing in the cruise flight phase. A tilt-rotor electric propulsion system is designed, and only one set of power unit is used to achieve the multiple working conditions of vertical take-off, tilting and cruise flight.

[0003] Distributed tilt-ducted electric vertical take-off and landing (EVTL) aircraft, a highly representative development direction for the next generation of eVTOLs, utilize a distributed ducted tilt propulsion system design. This not only enables VTOL capabilities, but also utilizes the boundary layer design and coupling effect of the wing and duct during cruise flight to achieve high-speed and efficient cruise flight, meeting the needs of long-range intercity flights and high-speed general aviation. Therefore, the development of its new, efficient, long-range electric propulsion system has become a key breakthrough technology for the next generation of eVTOL aircraft.

[0004] However, the complex physical processes and coupling mechanisms within the system, including 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 of existing eVTOL, and inability to meet the needs of long-range inter-city and high-speed navigation flights.

[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 tilting mechanism; a ducted fan is provided on the wing, 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 inlet axis center 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 axis centers of adjacent ducted fans is Z=1.2R~3R, and Z<0.3L d The distance between the ducted fan closest to the root of the wing and the center of its axis 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 a working state of providing vertical lift and horizontal thrust.

[0007] In one embodiment, the tilting mechanism includes a drive motor, a gear set and a rotating shaft; the drive 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 separately 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 embodiment, 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 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 embodiment, 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] The aerodynamic-propulsion coupling characteristics of the distributed ducted fan powered wing electric propulsion system of the present invention exhibit excellent aerodynamic and propulsion characteristics during high-speed cruise flight. The internal and external airflows of the propulsion system are strongly coupled with the airflow on the wing surface. Furthermore, at high-speed flight, the ducted fan's performance is optimal. Due to the ducted fan's suction effect, which further accelerates the airflow on the wing's upper surface and the coupling of the ducted fan's wake to the wing's downwash, the wing's lift-to-drag ratio and the ducted fan's static thrust are significantly increased, thereby reducing cruise power consumption and meeting the aircraft's requirements for long-range intercity flights and high-speed general aviation.

[0014] Regarding the distributed design of the distributed ducted fan power wing electric propulsion system of the present invention, different schemes are available for the distribution of the ducted fans. The distribution of the ducted fan units on the upper surface of the wing's trailing edge can be designed in different ways, including: the chord-wise distance X between the ducted fan inlet and the wing's leading edge point; the vertical distance Y between the ducted fan axis and the wing's upper surface; and the spacing Z between ducted fans. Through calculation and analysis, the present invention selected a set of optimal XYZ distribution parameters as the ducted fan distribution parameter device, and based on this, carried out the integrated design of the ducted fan and flap.

[0015] For the integrated 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 distributed ducted components and utilizing the aerodynamic propulsion coupling effect mechanism. A group of distributed ducted components is composed of two or more ducted fan units. The duct units of the same component have the same duct performance, rotation direction, duct distribution position on the wing, duct and wing installation angle and other parameters. The wing and the distributed ducted components are integrated into 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 duct suction effect.

[0016] For the tilt control of the distributed ducted fan power wing electric propulsion system of the present invention, an integrated tilt control design is adopted. The fused flap duct component is connected to the rotating shaft through a connector. The electronic control system is responsible for providing power and control signals to the drive unit of the tilt mechanism. The drive unit drives the rotating shaft to rotate, realizes the tilt of the fused flap duct component, and realizes the state switching of the power group, 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 cruise 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 following is a brief introduction to the drawings required for use in the implementation. Obviously, the drawings described below are only some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 is a schematic diagram of the 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 This 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. Mid-wing 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 parts. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to 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 distance between the axis centers of 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 spacing of Z0 = 0.05Ld ~ 0.15L between its axis center and the root of the wing 10 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 provided 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, this embodiment provides a wing 10 including 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 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] Moreover, 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 the installation and fixation of the shaft 23 .

[0036] Regarding the tilting mechanism 20, the tilting mechanism 20 is used to synchronously adjust the tilting angles of the multiple ducted fans 11 so that the multiple ducted fans 11 can at least provide vertical lift and horizontal thrust. To achieve this function, Figure 2As shown, this embodiment provides a tilting mechanism 20 including a drive motor 21, a gear set 22 and a rotating shaft 23; the drive 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] 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 become an integrated structure that tilts synchronously, ensuring that the two can always maintain a constant relative position and prevent interference from occurring.

[0038] Furthermore, because the ducted fan 11 has high voltage requirements, varying voltage values ​​can severely impact motor performance. Therefore, this embodiment employs a distributed ducted fan propulsion system to power multiple ducted fans 11 in parallel, ensuring consistent operating voltage across them. The system is then connected in series with the battery, meaning each ducted fan 11 is individually connected to an electronic speed regulator, which is then connected to a power source. Several such individual ducted circuits are then connected in parallel to form a distributed ducted circuit.

[0039] It should also be added that the present invention mainly uses carbon fiber to make a wing spar 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 and 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. The tilt mechanism 20 utilizes an integrated rotating shaft 23, driven by a drive motor 21 and a gear set 22. The design consists of an external section and an internal mounting section. In the external section, the ducted fan 11 is connected to the rotating shaft 23 and flap 18 via a connector 24, forming a structurally integrated structure. One end of the rotating shaft 23 is secured to the wing rib 10 via a bearing, minimizing deformation. The drive motor 21 then rotates the rotating shaft 23, enabling the tilting of multiple ducted fans 11. In the internal mounting section, the other end of the rotating shaft 23 is secured to the mounting platform via a bearing seat. The rotating shaft 23 is connected to the drive motor 21 via gear meshing. The drive motor 21 drives the gear set 22, which in turn rotates the rotating shaft 23, thereby achieving tilting of the ducted fans 11. Internally, the wing 10 includes a design for routing wiring for the electrical control system and for installing the electronically controlled servos.

[0040] The present invention also studies the impact of the distribution design of the ducted fan 11 on the wing 10 on the performance of the electric propulsion system, including the effects of the chord-wise, span-wise, and longitudinal distribution of the ducted fan 11 on the upper surface of the wing 10 on the system's aerodynamic and propulsive performance. By exploring this, a set of optimal ducted distribution parameters was selected, and the integrated design of the ducted fan 11 and flap 18 was conducted. Furthermore, the present invention explores the impact of the suction coupling effect of the inlet flow field between the ducted fan 11 and the ducted fan 11 on ducted performance; the impact of the aerodynamic-propulsive coupling of the inlet flow field of the ducted fan 11 with the flow field on the surface of the wing 10 on the aerodynamic and propulsive performance of the wing 10; and the effect of the suction effect at the inlet of the ducted fan 11 on suppressing flow separation on the wing 10 and increasing lift. By exploring the coupling effects and underlying physical mechanisms of the distributed ducted propulsion wing configuration, the integrated design and optimization of the ducted fan 11 and flap 18, the design of boundary layer induction technology, and the design of aerodynamic-propulsive coupling are conducted, achieving the goal of improving the performance of the new electric propulsion system.

[0041] Through research, this invention proposes a novel electric propulsion system design that combines the dynamic characteristics of a ducted fan 11 with the aerodynamic characteristics of a wing 10. By exploring the coupling effect between the two and optimizing the design based on the mechanism, the aerodynamic and propulsion performance of the combined electric propulsion system is improved. Specifically, multiple ducted fans 11 on the same wing 10 have the same ducted performance and distribution parameters. The wing 10 and ducted fan 11 are integrated into a fused flap ducted element, which, together with the flap 18, enhances the propulsion performance and aerodynamic efficiency of the novel propulsion system by utilizing the aerodynamic-propulsion coupling effect and the ducted suction effect. Furthermore, the fused flap ducted element utilizes an integrated tilt control design. The electronic control system provides power and control signals, and the drive unit drives the rotation shaft 23 to achieve tilt of the fused flap ducted element, enabling the propulsion system to meet the diverse flight conditions of eVTOL flight.

[0042] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles 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 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 section of the ducted fan and the leading edge 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-axis distance between 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 plurality of ducted fans so that the plurality of ducted fans are capable of at least providing vertical lift and horizontal thrust; 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; The rotating shaft is provided with a plurality of connecting members, which are arranged separately along the axial direction of the rotating shaft, and 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; 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; The wing comprises a root rib, a middle rib, an end rib, a spar and a foam shell; From the root of the wing toward the wingtip of the wing, the root rib, the middle rib and the end rib are sequentially separated and arranged relative to each other; The spar passes through the root rib, the middle rib and the end rib; The foam shell covers the outer surface of the wing; 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.

2. The distributed ducted fan power 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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