A distributed tilt-ducted fan electric vertical take-off and landing aircraft

Abstract

The present invention discloses a distributed tilt-ducted fan electric vertical take-off and landing aircraft, comprising a fuselage, a front wing and a front tilt mechanism arranged in front of the fuselage, and a rear wing and a rear tilt mechanism arranged behind the fuselage; the front wing is provided with a front ducted fan, and a plurality of front ducted fans are arranged separately along the wingspan direction of the upper surface of the front wing; the front tilt mechanism is used to adjust the tilt angles of the plurality of front ducted fans so that the plurality of front ducted fans at least have a working state of providing vertical lift and horizontal thrust; the rear wing is provided with a rear ducted fan, and a plurality of rear ducted fans are arranged separately along the wingspan direction of the upper surface of the rear wing; the rear tilt mechanism is used to adjust the tilt angles of the plurality of rear ducted fans so that the aircraft can take off and land vertically, perform tilt transition and cruise horizontally; after adopting the above scheme, it will be possible to solve the problems of low flight efficiency of existing eVTOL, difficulty in taking off and landing in cities, low range and speed, and poor reliability of tilt transition.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft, and in particular to a distributed tilt-ducted fan electric vertical take-off and landing aircraft. Background Art

[0002] Electric vertical take-off and landing (eVTOL) vehicles are intelligent, low-noise, low-cost, environmentally friendly, and highly safe future urban air vehicles. Traditional propulsion systems for low-altitude urban air transportation face a range of challenges, including structural vibration, aerodynamic noise, exhaust emissions, cost-effectiveness, flight controllability, and reliability.

[0003] With the gradual improvement of power batteries and high-performance electric drive systems, distributed tilting ducted fan pure electric drive systems have gradually become a key direction of eVTOL power system research and development. Currently, the development of distributed tilting ducted fan eVTOLs with both high performance and high reliability is still in its infancy in China. Summary of the Invention

[0004] The purpose of the present invention is to provide a distributed tilt-ducted fan electric vertical take-off and landing aircraft to solve the problems of low flight efficiency, difficult take-off and landing in cities, low range and speed, and poor tilt transition reliability of existing eVTOLs.

[0005] In order to solve the above technical problems, the present invention provides a distributed tilt-ducted fan electric vertical take-off and landing aircraft, comprising a fuselage, a front wing and a front tilt mechanism arranged in front of the fuselage, and a rear wing and a rear tilt mechanism arranged behind the fuselage; the front wing is provided with a front ducted fan, and a plurality of the front ducted fans are arranged separately along the wingspan direction of the front wing; the front tilt mechanism is used to adjust the tilt angles of the plurality of front ducted fans so that the plurality of front ducted fans at least have a working state of providing vertical lift and horizontal thrust; the rear wing is provided with a rear ducted fan, and a plurality of the rear ducted fans are arranged separately along the wingspan direction of the rear wing; the rear tilt mechanism is used to adjust the tilt angles of the plurality of rear ducted fans so that the plurality of rear ducted fans at least have a working state of providing vertical lift and horizontal thrust.

[0006] In one embodiment, the front ducted fans and the rear ducted fans are arranged alternately in a direction in which the wings are arranged transversely along the fuselage.

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

[0008] In one embodiment, the front flap of the front wing is connected to the front rotating shaft so that the front flap and the front ducted fan become a synchronously tilting structure.

[0009] In one embodiment, the rear tilting mechanism includes a rear drive motor, a rear gear set and a rear shaft; the rear drive motor is used to drive the rear gear set to rotate; the rotation of the rear gear set is used to drive the rear shaft to rotate; a plurality of rear connecting members are provided on the rear shaft, and the plurality of rear connecting members are arranged and separated along the axial direction of the rear shaft, and the plurality of rear connecting members are respectively connected to the rear ducted fan, and the rotation of the rear shaft is used to drive the rear ducted fan to tilt.

[0010] In one embodiment, the rear flap of the rear wing is connected to the rear shaft so that the rear flap and the rear ducted fan become a synchronously tilting structure.

[0011] In one embodiment, the geometrical outer profile of the distributed tilt-ducted fan electric vertical take-off and landing aircraft meets the requirement of S=L d1 c1+L d2 The parametric iterative calculation result of c2; where S is the lift requirement area of ​​the distributed tilt-ducted fan electric vertical take-off and landing aircraft, L d1 is the wingspan length of the front wing, L d2 is the wingspan length of the rear wing, c1 is the chord length of the front wing, and c2 is the chord length of the rear wing.

[0012] In one embodiment, the distributed tilt-ducted fan electric vertical take-off and landing aircraft has a tandem wing layout, the fuselage is a teardrop-shaped fuselage, and in the height direction of the fuselage, the setting position of the front wing is lower than the setting position of the rear wing.

[0013] In one embodiment, the lift ratio of the front wing to the rear wing is L f :L a =0.8~1.2:1.8~2.2; among which, L f is the theoretical required lift of the front wing, L a is the theoretical required lift of the rear wing.

[0014] In one embodiment, when the distributed tilt-ducted fan electric vertical take-off and landing aircraft performs vertical ascent and descent, its lift ratio is F1:F2=1.8~2.2:2.8~3.2; when the distributed tilt-ducted fan electric vertical take-off and landing aircraft performs climbing with a tilt angle, its lift complies with F1sinθ1:F2sinθ2=1.8~2.2:2.8~3.2; when the distributed tilt-ducted fan electric vertical take-off and landing aircraft performs hovering, its lift ratio is F1:F2=1.8~2.2:2.8~3.2; when the distributed tilt-ducted fan electric vertical take-off and landing aircraft performs cruising, the thrust provided by the front ducted fan and the rear ducted fan complies with 14F r =D; wherein, F1 is the required thrust of a single front ducted fan, F2 is the required thrust of a single rear ducted fan, θ1 is the tilt angle of the front ducted fan, θ2 is the tilt angle of the rear ducted fan, F r is the thrust required by each of the front ducted fan and the rear ducted fan during cruising, and D is the resistance encountered by the distributed tilt-ducted fan electric vertical take-off and landing aircraft during cruising.

[0015] The beneficial effects of the present invention are as follows:

[0016] Since this aircraft adopts a tandem wing layout and is designed with two main wings at the front and rear to provide lift to offset gravity, its streamlined fuselage and nose-up moment characteristics will reduce flight resistance and facilitate aerodynamic balancing. The combination of the front and rear ducted fans and the front and rear tilt devices realizes the distributed tilt-ducted fans distributed on the upper surfaces of the front and rear wings as the power unit of the aircraft, providing lift and cruise thrust for the aircraft to take off and land. Furthermore, the distributed ducted fan power unit can be tilted 90° to ensure that the aircraft has multi-mode flight with take-off and landing, cruise tilt transition.

[0017] Therefore, after adopting the present invention, it will be possible to solve the problems of low flight efficiency of existing eVTOL, difficulty in taking off and landing in cities, low range and speed, and poor reliability of tilt transition. 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 It is a structural diagram provided by an embodiment of the present invention;

[0020] Figure 2 yes Figure 1 Schematic diagram of the internal structure;

[0021] Figure 3 yes Figure 1 Schematic diagram of vertical lifting state;

[0022] Figure 4 yes Figure 1 Schematic diagram of climbing state with tilt angle;

[0023] Figure 5 yes Figure 1 Schematic diagram of the cruise state.

[0024] The reference numerals are as follows:

[0025] 10. Body;

[0026] 20. Front wing; 21. Front ducted fan; 22. Front flap;

[0027] 30. Forward tilt mechanism; 31. Front drive motor; 32. Front gear set; 33. Front shaft; 34. Front connecting piece;

[0028] 40. Rear wing; 41. Rear ducted fan; 42. Rear flap;

[0029] 50. Rear tilting mechanism; 51. Rear drive motor; 52. Rear gear set; 53. Rear rotating shaft; 54. Rear connecting piece. DETAILED DESCRIPTION

[0030] 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.

[0031] The present invention provides a distributed tilting ducted fan electric vertical take-off and landing aircraft, which is implemented as follows: Figure 1 and Figure 2 As shown, the aircraft includes a fuselage 10 , a front wing 20 and a front tilt mechanism 30 provided in front of the fuselage 10 , and a rear wing 40 and a rear tilt mechanism 50 provided behind the fuselage 10 .

[0032] Regarding the fuselage 10, its outer shell is composed of a 3D printed skin and a rib structure of the fuselage 10, and then the rib structure of the fuselage 10 is installed with the fuselage load-bearing structure by mortise and tenon joints; among them, the fuselage load-bearing structure is a concentrated load-bearing component of the aircraft and a component for the main load distribution of the aircraft, and has high requirements for structural strength and rigidity. Taking into account the loading space and weight reduction requirements of the aircraft, a truss mortise and tenon joint structure is mainly adopted as the fuselage main body design, and the bottom plate of the fuselage 10 adopts an integral carbon fiber mesh structure as a base plate; and belly ribs are designed on both sides of the bottom plate of the fuselage 10 to enhance the front and rear torsional properties of the fuselage 10; a front wing mounting platform is designed at the front of the bottom plate of the fuselage 10 to fix the front wing 20 and install the front tilt mechanism 30; a rear wing mounting platform is designed at the rear of the bottom plate of the fuselage 10 to fix the rear wing 40 and install the rear tilt mechanism 50; the front and rear are connected and fixed by the middle plate of the fuselage 10 to further enhance the front and rear torsional and bending properties.

[0033] And as Figure 1 As shown, this embodiment arranges the distributed tilt-ducted fan electric vertical take-off and landing aircraft in a tandem wing layout, the fuselage 10 is a teardrop-shaped fuselage, and in the height direction of the fuselage 10, the setting position of the front wing 20 is lower than the setting position of the rear wing 40; under the influence of the streamline and nose-up moment characteristics of the teardrop-shaped fuselage, the flight resistance will be reduced and aerodynamic balancing will be facilitated; it should be pointed out that through simulation calculation of the aerodynamic conditions of the aircraft shape, it can be seen that the lift-to-drag ratio of the aircraft adopting the teardrop-shaped fuselage layout is approximately 7 at most.

[0034] Regarding the front wing 20, it uses carbon fiber tubes as wing beams, which together with carbon fiber ribs form the load-bearing structure of the front wing 20, and uses foam materials to make the shape of the front wing 20, and as shown in FIG. Figure 1 As shown, this embodiment is provided with a front ducted fan 21 on the front wing 20, and a plurality of front ducted fans 21 are arranged separately along the wingspan direction of the front wing 20; specifically, at this time, three front ducted fans 21 are provided on both front wings 20, for a total of six front ducted fans 21, and a gap of 130 mm is provided between adjacent front ducted fans 21.

[0035] Regarding the front tilt mechanism 30, the front tilt mechanism 30 is used to adjust the tilt angles of the plurality of front ducted fans 21 so that the plurality of front ducted fans 21 can at least provide a working state of providing vertical lift and horizontal thrust. To achieve this function, Figure 2As shown, this embodiment provides a front tilting mechanism 30 including a front drive motor 31, a front gear set 32 ​​and a front rotating shaft 33; the front drive motor 31 is used to drive the front gear set 32 ​​to rotate; the rotation of the front gear set 32 ​​is used to drive the front rotating shaft 33 to rotate; a plurality of front connecting members 34 are provided on the front rotating shaft 33, and the plurality of front connecting members 34 are arranged and separated along the axial direction of the front rotating shaft 33, and the plurality of front connecting members 34 are respectively connected to the front ducted fan 21, so that the rotation of the front rotating shaft 33 can be used to drive the front ducted fan 21 to tilt.

[0036] In order to avoid interference between the front ducted fan 21 and the front wing 20 during the tilting process, this embodiment also arranges the front flap 22 of the front wing 20 to be connected to the front rotating shaft 33, so that the front flap 22 and the front ducted fan 21 become a synchronous tilting structure, ensuring that the two can always maintain a constant relative position and prevent interference from occurring.

[0037] Regarding the rear wing 40, it uses carbon fiber tubes as wing beams, and carbon fiber ribs to form the load-bearing structure of the rear wing 40. Foam material is used to make the shape of the rear wing 40, and as shown in FIG. Figure 1 As shown, this embodiment is provided with a rear ducted fan 41 on the rear wing 40, and multiple rear ducted fans 41 are arranged separately along the wingspan direction of the rear wing 40; specifically, at this time, four rear ducted fans 41 are provided on both rear wings 40, totaling eight rear ducted fans 41, and a gap of 130 mm is provided between adjacent rear ducted fans 41.

[0038] Regarding the rear tilting mechanism 50, the rear tilting mechanism 50 is used to adjust the tilting angles of the plurality of rear ducted fans 41 so that the plurality of rear ducted fans 41 can at least provide a working state of providing vertical lift and horizontal thrust. To achieve this function, Figure 2 As shown, this embodiment provides a rear tilting mechanism 50 including a rear drive motor 51, a rear gear set 52 and a rear rotating shaft 53; the rear drive motor 51 is used to drive the rear gear set 52 to rotate; the rotation of the rear gear set 52 is used to drive the rear rotating shaft 53 to rotate; a plurality of rear connecting members 54 are provided on the rear rotating shaft 53, and the plurality of rear connecting members 54 are arranged and separated along the axial direction of the rear rotating shaft 53, and the plurality of rear connecting members 54 are respectively connected to the rear ducted fan 41, so that the rotation of the rear rotating shaft 53 can be used to drive the rear ducted fan 41 to tilt.

[0039] In order to avoid interference between the rear ducted fan 41 and the rear wing 40 during the tilting process, this embodiment also arranges the rear flap 42 of the rear wing 40 to be connected to the rear shaft 53, so that the rear flap 42 and the rear ducted fan 41 become a synchronous tilting structure, ensuring that the two can always maintain a constant relative position and prevent interference from occurring.

[0040] It should also be pointed out that the influence of the duct distribution design on the duct performance at this time mainly includes the influence of the coupling effect of the inlet flow field between the ducts on the duct performance, the influence of the coupling effect of the duct inlet flow field and the wing surface flow field on the wing performance and duct performance, the influence of the coupling effect between the front duct outlet flow field, the rear duct inlet flow field and the front and rear wings 40 flow fields on the overall lift characteristics and propulsion characteristics of the aircraft, etc. Therefore, in order to reduce the inlet coupling effect of the outlet jet of the front duct fan 21 on the rear duct fan 41, as shown in FIG. Figure 1 As shown, in this embodiment, the front ducted fans 21 and the rear ducted fans 41 are arranged alternately in the direction of the lateral arrangement of the wings along the fuselage 10, thereby reducing the adverse effects of the coupling effect and thereby improving the performance of the aircraft power system.

[0041] Furthermore, because ducted fans have high voltage requirements, varying voltage values ​​can significantly impact motor performance. Therefore, this embodiment connects the front ducted fan 21 and the rear ducted fan 41 in parallel to obtain power, ensuring consistent operating voltages for both fans. The circuit is then connected in series with the battery, meaning each ducted fan is individually connected to an electronic speed controller, which is then connected to a power source. Several such single ducted circuits are then connected in parallel to form a distributed ducted circuit.

[0042] The basic structural design points of the present invention are known from the above, and will be explained below in combination with specific design parameters to demonstrate the excellent performance of the present invention through real data.

[0043] 1.1 Overall performance indicators

[0044] For a certain mission scenario, basic requirements for the overall performance of the aircraft need to be put forward, as shown in Table 1-1.

[0045] Table 1-1 Overall performance indicators

[0046]

[0047] Specifically, in terms of size and weight levels, this embodiment defines its takeoff weight range and maximum size outline through aerodynamic theory calculation and estimation to adapt to the mission requirements of flexible take-off and landing in a small space and simple take-off and landing site; in terms of load capacity, according to the requirement of the 5kg load index, this embodiment sets the aircraft's payload mass and volume as the overall design index; in terms of cruise performance, a comprehensive investigation is conducted on current aircraft of the same type, and its minimum flight speed index is set to ensure that the aircraft has good low-speed performance and better adapts to the mission requirements of shuttle take-off and landing between buildings; in terms of maintainability, the aircraft is required to have a high degree of modular design, and to ensure that major components can be quickly disassembled and assembled, so as to reduce the aircraft's maintenance costs and comprehensive operating costs.

[0048] 1.2 Aerodynamic performance indicators:

[0049] According to the force balance of an aircraft during cruising flight, gravity equals lift, and thrust equals drag, that is:

[0050]

[0051] Where L is the required lift (lift), and the air density is ρ = 1.225 kg / m 3 , C l is the lift coefficient, S is the lift requirement area of ​​the distributed tilt-ducted fan electric vertical take-off and landing aircraft, G is the designed take-off mass of the aircraft, and in this solution, G = 25 kg, and v is the designed cruising speed, and in this solution, v = 27 m / s;

[0052] According to the lift coefficient C of fixed-wing cruise flight l =0.7, cruising speed v = 27m / s, we can get:

[0053]

[0054] It can be seen that the theoretical requirement for the lift area S is 0.784m 2 , and then according to the geometrical outer contour of the distributed tilt-ducted fan electric vertical take-off and landing aircraft, S=L d1 c1+L d2 The parametric iterative calculation result of c2, so after the parametric iterative calculation, the geometric outline of the aircraft will be obtained; specifically, the parametric calculation here is mainly grouped according to the size of the prototype, and the c1, c2, L d1 / L d2 Perform parameter assignment calculation to obtain the total wingspan length L d1 +L d2 The evaluation factor is that the value is around 2m.

[0055] Lift ratio of front and rear wings:

[0056] Among them, L d1 is the wingspan length of the front wing 20, L d2 is the wingspan of the rear wing 40, c1 is the chord length of the front wing 20, c2 is the chord length of the rear wing 40, S f is the wing area of ​​the front wing 20, S a is the wing area of ​​the rear wing 40, L f is the theoretical required lift of the front wing 20, L a is the theoretical required lift of the rear wing 40.

[0057] Obviously, L f With L aThe ratio is not unique, and the preferred reference range is that the lift ratio of the front wing 20 to the rear wing 40 is L f :L a =0.8~1.2:1.8~2.2.

[0058] 1.3 Power performance indicators:

[0059] 1.3.1 Vertical Take-off and Landing Modal Analysis

[0060] like Figure 3 As shown, when the aircraft takes off and lands vertically, the front ducted fan 21 and the rear ducted fan 41 are tilted 90 degrees, the vertical acceleration is set to a = 0.1g, and the vertical takeoff resistance is set to f 阻 =0.1mg, and the force analysis shows:

[0061]

[0062] According to lift ratio = thrust ratio, we can get

[0063] Wherein, g is the acceleration of gravity, m is the takeoff mass of the aircraft, F1 is the required thrust of a single front ducted fan 21 , and F2 is the required thrust of a single rear ducted fan 41 .

[0064] Obviously, the ratio of F1 to F2 is not unique. The preferred reference range is that when the distributed tilt-ducted fan electric vertical take-off and landing aircraft performs vertical take-off and landing, its lift ratio is F1:F2=1.8~2.2:2.8~3.2.

[0065] 1.3.2 When climbing with a tilt angle

[0066] like Figure 4 As shown, when the aircraft climbs with a tilt angle, the front ducted fan 21 and the rear ducted fan 41 tilt to a certain angle, and the vertical acceleration is a y , horizontal acceleration a x It can be set to 0.2g-0.5g.

[0067] 6*F1sinθ1+8*F2sinθ2-f 阻y +f 升 -mg=ma y ;

[0068] 6*F1cosθ1+8*F2cosθ2-f 阻x =ma x

[0069] At this time, the speed is low and the lift generated is small. To simplify the calculation, the lift and all the resistance are offset. In order to maintain the stability of the aircraft torque, the lift ratio is still equal to the thrust ratio:

[0070]

[0071] Among them, f 阻y is the component of the resistance in the direction of gravity during the tilting process, f 阻x is the horizontal component of the resistance during the tilting process, f 升 is the lift generated by the aircraft, θ1 is the tilt angle of the front ducted fan 21, and θ2 is the tilt angle of the rear ducted fan 41.

[0072] Obviously, the ratio of F1sinθ1 to F2sinθ2 is not unique. The preferred reference range is that when the distributed tilt-ducted fan electric vertical take-off and landing aircraft climbs with a tilt angle, its lift meets the requirements of F1sinθ1: F2sinθ2 = 1.8~2.2: 2.8~3.2.

[0073] 1.3.3 Hovering segment:

[0074] According to the vertical force balance, we have: 6*F1+8*F2=mg

[0075] Obviously, the ratio of F1 to F2 is not unique. The preferred reference range is that when the distributed tilt-ducted fan electric vertical take-off and landing aircraft is hovering, its lift ratio is F1:F2=1.8~2.2:2.8~3.2.

[0076] 1.3.4 Cruise segment:

[0077] like Figure 5 As shown, the front ducted fan 21 and the rear ducted fan 41 provide horizontal thrust in the direction shown. When the distributed tilt-ducted fan electric vertical take-off and landing aircraft is cruising, the thrust provided by the front ducted fan 21 and the rear ducted fan 41 meets 14F r =D, and the force analysis of the cruise state when the lift-to-drag ratio is 8 is:

[0078]

[0079] That is, the cruise single duct thrust F T =0.223kg;

[0080] At this time, F r is the thrust required by each front ducted fan 21 and the rear ducted fan 41 during cruising, D is the drag encountered by the distributed tilt-ducted fan electric vertical take-off and landing aircraft during cruising, and k is the lift-to-drag ratio, which is the ratio of lift to drag.

[0081] Therefore, the power system design indicators are shown in Table 1-2 below.

[0082] Table 1-2 Design indicators of power propulsion system

[0083]

[0084]

[0085] In summary, the present invention has at least the following beneficial effects:

[0086] 1. As for the main body structure of the present invention, the front wing 20, the rear wing 40, and the fuselage 10 are connected to the body structure through various connecting parts. The front wing 20 is installed on the front wing mounting platform, which is responsible for fixing the front wing 20 to disperse and transmit the force of the front wing 20 and installing the front tilting mechanism 30 to realize the tilting of the front ducted fan 21; the rear wing 40 is installed on the rear wing mounting platform, which is responsible for fixing the rear wing 40 to disperse and transmit the force of the rear wing 40 and installing the rear tilting mechanism 50 to realize the tilting of the rear ducted fan 41; the fuselage 10 is fixed to the bottom connecting plate through the load-bearing truss ribs, which is responsible for fixing the fuselage 10 and dispersing and transmitting the force of the fuselage 10; the fuselage 10, the front and rear wings 40, and the front and rear tilting mechanisms 50 are all installed on the body load-bearing structure to constitute the main body structure of the aircraft, thereby ensuring the structural strength and rigidity requirements of the aircraft.

[0087] 2. Regarding the aerodynamic coupling characteristics of the aircraft of the present invention, it exhibits 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 surface of the aircraft, significantly impacting the lift of the front and rear wings 40 and the thrust of the front and rear ducted fans 41. Simulations of the aerodynamics of the aircraft's exterior have shown that the maximum lift-to-drag ratio for an aircraft with a teardrop-shaped fuselage layout is approximately 7. Furthermore, experimental measurements of the wing ducted fan components have revealed that the thrust of the ducted fan significantly improves the performance of the ducted fan, significantly increasing the lift of the wing.

[0088] 3. For the distributed power unit of the present invention, there are different schemes for the distribution design of the ducted fans. The distribution of the front and rear ducted fans 41 on the upper surface of the trailing edge of the front and rear wings 40 has different designs, including: the chord-wise distance X between the inlet of the front and rear ducted fans 41 and the leading edge point of the front and rear wings 40, the vertical distance Y between the axis of the front and rear ducted fans 41 and the upper surface of the front and rear wings 40, and the spacing Z between each front and rear ducted fan 41. Through calculation and analysis, the present invention selects a set of better XYZ distribution parameters to form a distributed ducted fan power unit. The power unit and the trailing edge flaps of the wing are connected to the rotating shaft of the tilting mechanism through a connector. The driving output of the tilting mechanism drives the rotating shaft to rotate through a gear transmission. The rotating shaft drives the distributed ducted fan power unit and the trailing edge flaps to tilt, realizing the state switching of the power group.

[0089] 4. As for the multimodal flight function of the aircraft of the present invention, it has a variety of airworthy flight modes, such as vertical take-off and landing flight mode, tilt-transition flight mode and fixed-wing cruise flight mode. When the ducted fan power group is tilted 90°, that is, when the ducted outlet is perpendicular to the ground, it is responsible for generating lift, offsetting the gravity of the aircraft, and realizing vertical take-off and landing flight; when the ducted fan power group is tilted 0°, that is, the ducted fan outlet is consistent with the incoming flow direction, it is responsible for generating thrust, offsetting the aircraft resistance, and realizing high-speed cruise flight. When the ducted fan changes from 90° to 0°, the ducted fan power group provides part of the lift and thrust of the aircraft, and the other part of the lift is generated by the wings. At this time, the aircraft is in a tilt-transition flight mode.

[0090] 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 tilt-ducted fan electric vertical take-off and landing aircraft, characterized in that: It comprises a fuselage, a front wing and a forward tilting mechanism arranged in front of the fuselage, and a rear wing and a rear tilting mechanism arranged in the rear of the fuselage; The front wing is provided with a front ducted fan, and a plurality of the front ducted fans are arranged separately along the wingspan direction of the front wing; The front tilt mechanism is used to adjust the tilt angles of the plurality of front ducted fans so that the plurality of front ducted fans are capable of at least providing vertical lift and horizontal thrust; The rear wing is provided with a rear ducted fan, and a plurality of the rear ducted fans are arranged separately along the span direction of the rear wing; The rear tilt mechanism is used to adjust the tilt angles of the plurality of rear ducted fans so that the plurality of rear ducted fans are capable of at least providing vertical lift and horizontal thrust; The geometrical outer contour of the distributed tilting ducted fan electric vertical take-off and landing aircraft conforms to S=L d1 c1+L d2 Parameterized iterative calculation results of c2; Wherein, S is the lift requirement area of ​​the distributed tilt-ducted fan electric vertical take-off and landing aircraft, L d1 is the wingspan length of the front wing, L d2 is the wingspan of the rear wing, c1 is the chord length of the front wing, and c2 is the chord length of the rear wing; When the distributed tilting ducted fan electric vertical take-off and landing aircraft performs vertical take-off and landing, its lift ratio is F1:F2=1.8~2.2:2.8~3.2; When the distributed tilt-ducted fan electric vertical take-off and landing aircraft performs a climb with a tilt angle, its lift complies with F1sinθ1:F2sinθ2=1.8~2.2:2.8~3.2; When the distributed tilt-ducted fan electric vertical take-off and landing aircraft is hovering, the lift ratio thereof is F1:F2=1.8~2.2:2.8~3.2; When the distributed tilt-ducted fan electric vertical take-off and landing aircraft is cruising, the thrust provided by the front ducted fan and the rear ducted fan meets 14F r =D; Wherein, F1 is the required thrust of the single front ducted fan, F2 is the required thrust of the single rear ducted fan, θ1 is the tilt angle of the front ducted fan, θ2 is the tilt angle of the rear ducted fan, F r is the thrust required by each of the front ducted fan and the rear ducted fan during cruising, and D is the resistance encountered by the distributed tilt-ducted fan electric vertical take-off and landing aircraft during cruising.

2. The distributed tilt-ducted fan electric vertical take-off and landing aircraft according to claim 1, characterized in that: In the direction of the lateral arrangement of the wings along the fuselage, the front ducted fans and the rear ducted fans are arranged alternately.

3. The distributed tilt-ducted fan electric vertical take-off and landing aircraft according to claim 1, characterized in that: The front tilting mechanism includes a front drive motor, a front gear set and a front rotating shaft; The front drive motor is used to drive the front gear set to rotate; The rotation of the front gear set is used to drive the front rotating shaft to rotate; A plurality of front connecting parts are provided on the front rotating shaft, and the plurality of front connecting parts are arranged separately along the axial direction of the front rotating shaft. The plurality of front connecting parts are respectively connected to the front ducted fan, and the rotation of the front rotating shaft is used to drive the front ducted fan to tilt.

4. The distributed tilt-ducted fan electric vertical take-off and landing aircraft according to claim 3, characterized in that: The front flap of the front wing is connected to the front rotating shaft so that the front flap and the front ducted fan form a synchronous tilting structure.

5. The distributed tilt-ducted fan electric vertical take-off and landing aircraft according to claim 1, characterized in that: The rear tilting mechanism includes a rear drive motor, a rear gear set and a rear rotating shaft; The rear drive motor is used to drive the rear gear set to rotate; The rotation of the rear gear set is used to drive the rear shaft to rotate; The rear shaft is provided with a plurality of rear connecting members, which are arranged separately along the axial direction of the rear shaft. The plurality of rear connecting members are respectively connected to the rear ducted fan, and the rotation of the rear shaft is used to drive the rear ducted fan to tilt.

6. The distributed tilt-ducted fan electric vertical take-off and landing aircraft according to claim 5, characterized in that: The rear flap of the rear wing is connected to the rear rotating shaft so that the rear flap and the rear ducted fan form a synchronous tilting structure.

7. The distributed tilt-ducted fan electric vertical take-off and landing aircraft according to claim 1, characterized in that: The distributed tilt-ducted fan electric vertical take-off and landing aircraft has a tandem wing layout, the fuselage is a teardrop-shaped fuselage, and in the height direction of the fuselage, the setting position of the front wing is lower than the setting position of the rear wing.

8. The distributed tilt-ducted fan electric vertical take-off and landing aircraft according to claim 1, characterized in that: The lift ratio of the front wing to the rear wing is L f :L a =0.8~1.2:1.8~2.2; Among them, L f is the theoretical required lift of the front wing, L a is the theoretical required lift of the rear wing.

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