Distributed tilting ducted fan type electric vertical take-off and landing aircraft

Abstract

The invention discloses a distributed tilting ducted fan type electric vertical take-off and landing aircraft which comprises an aircraft body, a front wing, a front tilting mechanism, a rear wing and a rear tilting mechanism, wherein the front wing and the front tilting mechanism are arranged in front of the aircraft body; front ducted fans are arranged on the front wings, and the multiple front ducted fans are separately arranged in the wingspan direction of the upper surfaces of the front wings; the front tilting mechanism is used for adjusting tilting 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 force and horizontal thrust force; the rear wing is provided with a plurality of rear ducted fans, and the plurality of rear ducted fans are separately arranged along the wingspan direction of the upper surface of the rear wing; the rear tilting mechanism is used for adjusting the tilting angles of the plurality of rear ducted fans, so that the aircraft can vertically take off and land, tilt transitions and horizontally cruise; after the scheme is adopted, the problems that an existing eVTOL is low in flight efficiency, difficult to take off and land in cities, low in voyage and speed, poor in tilting transition reliability and the like can be solved.

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 aircraft (eVTOL) is a future urban aerial general-purpose aircraft that is intelligent, low-noise, low-cost, green and highly safe. For urban low-altitude air traffic vehicles, traditional power systems face a series of problems such as structural vibration, aerodynamic noise, exhaust emissions, economy, flight controllability and reliability.

[0003] With the gradual improvement of power batteries and high-performance electric drive systems, the distributed tilt-ducted fan pure electric drive system has gradually become the focus of eVTOL power system research and development. At present, the distributed tilt-ducted fan eVTOL 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; a front ducted fan is arranged on the front wing, 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; a rear ducted fan is arranged on the rear wing, 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 of the embodiments, 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 members are provided on the front rotating shaft, and the plurality of front connecting members are arranged and separated along the axial direction of the front rotating shaft, and the plurality of front connecting members 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 of the embodiments, 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 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 of the embodiments, 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 contour of the distributed tilt-ducted fan electric vertical take-off and landing aircraft meets S=L d1 c1+L d2 The parametric iterative calculation result 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 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 of the embodiments, 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 =08~1.2:1.8~2.2; where 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 of the embodiments, 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 with the front and rear tilt devices enables distributed tilt-ducted fans to be distributed on the upper surfaces of the front and rear wings as the power unit of the aircraft, providing lift and cruise thrust for takeoff and landing. Furthermore, the distributed ducted fan power unit can tilt 90° to ensure that the aircraft has multi-mode flight with takeoff and landing, cruise and tilt transition.

[0017] Therefore, after adopting the present invention, 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 can be solved. 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 It is a schematic diagram of the structure 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. Front tilt mechanism; 31. Front drive motor; 32. Front gear set; 33. Front rotating shaft; 34. Front connecting piece;

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

[0029] 50. rear tilting mechanism; 51. rear driving 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 in conjunction with the accompanying drawings in the embodiments of the present invention.

[0031] The present invention provides a distributed tilt-ducted fan electric vertical take-off and landing aircraft, the implementation of which is 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 arranged in front of the fuselage 10 , and a rear wing 40 and a rear tilt mechanism 50 arranged 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; wherein, the fuselage load-bearing structure is a concentrated force-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. Considering the loading space and weight reduction requirements of the aircraft, a truss mortise and tenon joint structure is mainly adopted as the main body design of the fuselage, 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 torsion resistance 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 torsion resistance and bending resistance.

[0033] And if Figure 1 As shown, this embodiment arranges the distributed tilt-ducted fan electric vertical take-off and landing aircraft with 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 can be reduced and aerodynamic balancing is convenient; it should be pointed out that through simulation calculation of the aerodynamic conditions of the aircraft shape, it can be known that the lift-to-drag ratio of the aircraft adopting the teardrop-shaped fuselage layout is at most about 7.

[0034] Regarding the front wing 20, it uses a carbon fiber tube as a wing beam, and forms a load-bearing structure of the front wing 20 with a carbon fiber wing rib, and uses a foam material to make the shape of the front wing 20, and as 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 at least have 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 driving motor 31, a front gear set 32 ​​and a front rotating shaft 33; the front driving 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] Furthermore, 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 form a synchronously tilting structure, ensuring that the two can always maintain a constant relative position and preventing interference from occurring.

[0037] Regarding the rear wing 40, a carbon fiber tube is used as a wing beam, and the carbon fiber ribs form a load-bearing structure of the rear wing 40. A foam material is used to make the shape of the rear wing 40. Figure 1 As shown, this embodiment is provided with a rear ducted fan 41 on the rear wing 40, and a plurality of 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, for a total of eight rear ducted fans 41, and a gap of 130 mm is provided between adjacent rear ducted fans 41.

[0038] Regarding the rear tilt mechanism 50, the rear tilt mechanism 50 is used to adjust the tilt angles of the plurality of rear ducted fans 41 so that the plurality of rear ducted fans 41 at least have a working state of providing vertical lift and horizontal thrust. 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 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 shaft 53 to rotate; a plurality of rear connecting members 54 are provided on the rear shaft 53, and the plurality of rear connecting members 54 are arranged and separated along the axial direction of the rear 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 shaft 53 can be used to drive the rear ducted fan 41 to tilt.

[0039] Furthermore, 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 synchronously 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 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 the duct performance, and 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. Therefore, in order to weaken 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, in the direction of the lateral arrangement of the wings along the fuselage 10, the front ducted fans 21 and the rear ducted fans 41 are arranged alternately, thereby reducing the adverse effects of the coupling effect and thereby improving the performance of the aircraft power system.

[0041] Furthermore, since the ducted fan has high voltage specifications, different voltage values ​​will seriously affect the performance of the motor. Therefore, this embodiment sets the front ducted fan 21 and the rear ducted fan 41 in parallel to obtain electrical energy, so that the operating voltages of the front ducted fan 21 and the rear ducted fan 41 are consistent, and then the circuit is connected in series with the battery, that is, a ducted fan is connected to an electronic speed regulator alone, and then connected to a power supply, and then a plurality of such single ducted circuits are connected in parallel to form a distributed ducted circuit.

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

[0043] 1.1 Overall performance indicators

[0044] For a certain mission scenario, basic requirements are required for the overall performance of the aircraft, 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 take-off weight range and maximum size outline through aerodynamic theoretical 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 5kg load index, this embodiment sets the aircraft payload mass and volume as the overall design index; in terms of cruise performance, a comprehensive investigation is made 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 maintenance cost and comprehensive operating cost.

[0048] 1.2 Aerodynamic performance indicators:

[0049] According to the force balance of the 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 this scheme takes G = 25kg, v is the designed cruising speed, and this scheme takes v = 27m / s;

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

[0053]

[0054] It can be seen that the theoretical requirement for 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 c2, so after the parametric iterative calculation, the geometric outline of the aircraft will be obtained; specifically, the parametric calculation here is mainly based on the size of the prototype for group calculation, c1, c2, L d1 / L d2 Calculate the total wingspan length L by assigning parameters d1 +L d2 The evaluation factor is that the value is about 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 length 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 =08~1.2:1.8~2.2.

[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°, the vertical acceleration is set to a = 0.1g, and the vertical take-off resistance is set to f 阻 =0.1mg, the force analysis is:

[0061]

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

[0063] Among them, g is the acceleration of gravity, m is the take-off 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 Climbing with a tilt angle

[0066] like Figure 4 As shown, when the aircraft is climbing 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 is offset by all the resistance. 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 requirement 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 phase:

[0077] like Figure 5 As shown, the front ducted fan 21 and the rear ducted fan 41 provide horizontal thrust in the direction shown in the figure. 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.

[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. As for the aerodynamic coupling characteristics of the aircraft of the present invention, it has excellent aerodynamic characteristics 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, which will have a great impact on the lift of the front and rear wings 40 and the thrust of the front and rear ducted fans 41. Through simulation calculation of the aerodynamic conditions of the aircraft shape, it can be known that the maximum lift-to-drag ratio of the aircraft with a teardrop-shaped fuselage layout is about 7; and through experimental measurements of the wing ducted fan components, it is found that the thrust of the ducted fan has a great improvement effect on the performance of the duct, which can greatly improve the lift of the wing.

[0088] 3. For the distributed power device 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 distance 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 device. The power device and the trailing edge flap of the wing are connected to the rotating shaft of the tilt mechanism through a connecting piece. The driving output of the tilt mechanism drives the rotating shaft to rotate through a gear transmission. The rotating shaft drives the distributed ducted fan power device and the trailing edge flap to tilt, thereby realizing the state switching of the power group.

[0089] 4. As for the multi-modal 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 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 tilt-ducted fan electric vertical take-off and landing aircraft, characterized in that: It comprises a fuselage, a front wing and a front 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 and in an array 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 the working state of providing vertical lift and horizontal thrust.

2. The distributed tilt-ducted fan electric vertical take-off and landing aircraft according to claim 1, characterized in that: In the direction in which the wings are arranged transversely 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 comprises a front driving 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 shaft to rotate; A plurality of front connecting members are provided on the front rotating shaft, and the plurality of front connecting members are arranged and separated along the axial direction of the front rotating shaft. The plurality of front connecting members are respectively connected to the front ducted fans, and the rotation of the front rotating shaft is used to drive the front ducted fans 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 synchronously 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 comprises 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, and are respectively connected to the rear ducted fans. The rotation of the rear shaft is used to drive the rear ducted fans 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 shaft so that the rear flap and the rear ducted fan form a synchronously tilting structure.

7. The distributed tilt-ducted fan electric vertical take-off and landing aircraft according to claim 1, characterized in that: The geometrical outer contour of the distributed tilt-ducted fan electric vertical take-off and landing aircraft meets S=L d1 c1+L d2 The parametric 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 length of the rear wing, c1 is the chord length of the front wing, and c2 is the chord length of the rear wing.

8. The distributed tilt-ducted fan electric vertical take-off and landing aircraft according to claim 7, 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.

9. The distributed tilt-ducted fan electric vertical take-off and landing aircraft according to claim 7, characterized in that: The lift ratio of the front wing to the rear wing is L f :L a =08~1.2:1.8~2.2; Among them, L f is the theoretical required lift of the front wing, L a is the theoretical required lift of the rear wing.

10. The distributed tilt-ducted fan electric vertical take-off and landing aircraft according to claim 7, characterized in 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; When the distributed tilt-ducted fan electric vertical take-off and landing aircraft performs a climb with a tilt angle, its lift meets the requirement of 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, 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 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 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, and 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.

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