Propeller wing blowing lift augmentation type multi-wing aircraft and control method thereof

Abstract

The invention belongs to the field of aircrafts, and discloses a propeller blowing wing lift augmentation type multi-wing aircraft and a control method thereof.The propeller blowing wing lift augmentation type multi-wing aircraft comprises a fuselage, wings, a control system and a forward pulling propeller, the wings are arranged in multiple rows, and each row of wings is composed of a left wing and a right wing which are symmetrically distributed on the two sides of the fuselage; the multiple rows of wings are symmetrically arranged on the fuselage along the axis of the fuselage according to the gravity center moment of the aircraft; the plurality of front pull propellers are arranged at the front lower part of the wing, and the center line of a propeller disc of each front pull propeller and the chord of the wing are arranged at an attack angle of an included angle alpha; the control system is used for controlling the control quantity of each control surface of the aircraft and the rotating speed and steering of the forward-pulling propeller. High-speed airflow blown by the forward pulling propellers flows to the wings at an attack angle alpha, and generates a pneumatic coupling lift augmentation effect with the wings to generate forward and upward pulling forces on the aircraft; the rotating speed of the front pull propellers on the front-row wings is increased through control of the control system, the fuselage tilts backwards by theta to raise the head, the rotating speed of the front pull motors and the lowering angles of the flaps and the ailerons are controlled through the control system, force borne by the aircraft in all directions is balanced to achieve hovering, and resultant force is made to be vertically upward to achieve vertical take-off. The resultant force is vertically downward to realize vertical landing, and the resultant force is forward to realize level flight cruise.

Description

Technical Field

[0001] The invention belongs to the technical field of aircraft, and in particular relates to a propeller-blown-wing lift-enhancing multi-wing aircraft and a control method thereof. Background Art

[0002] Common vertical take-off and landing fixed-wing aircraft include composite wings and tilt-rotor wings.

[0003] Among them, the tilt-rotor vertical take-off and landing fixed-wing aircraft tilts the rotor upward or forward as needed during vertical take-off and landing and level flight. It has many moving parts and poor controllability. Since the tilt-rotor is used as both a helicopter rotor during vertical take-off and landing and a fixed-wing thrust / propulsion propeller, the multi-modal comprehensive efficiency is low. It is difficult to turn from vertical to level flight, facing serious aerodynamic interference separation problems, and low safety.

[0004] Most composite wing vertical take-off and landing fixed-wing aircraft directly add multi-rotors on the basis of fixed wings. The multi-rotors provide lift during the vertical take-off and landing stage, and switch back to fixed-wing mode during the level flight stage. The front pull power provides the thrust and the wing provides the lift. Although the technology is highly mature, during vertical take-off and landing or cruising level flight, one of the two vertical and horizontal lift / thrust devices needs to stop working, completely becoming waste weight, resulting in low aerodynamic efficiency of the entire aircraft. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a propeller-blown-wing lift-enhancing multi-wing aircraft and a control method thereof, so as to solve the problems of the existing vertical take-off and fixed-wing aircraft having difficulty in converting from vertical to horizontal flight, severe aerodynamic interference and separation during conversion, low safety, complex structure, and low vertical take-off and landing efficiency.

[0006] According to an embodiment of the present invention, the present invention adopts the following technical solution:

[0007] A propeller-blown-wing multi-wing aircraft with enhanced lift, comprising a fuselage, wings, a control system and a forward-pull propeller, wherein the wings are arranged in multiple rows, each row of wings being composed of left and right wings symmetrically distributed on both sides of the fuselage, and the multiple rows of wings are arranged along the axis of the fuselage and distributed on the fuselage in a symmetrical manner according to the moment of gravity of the aircraft center;

[0008] There are multiple forward propellers, each of which is installed at the front lower part of the wing, and the center line of the propeller disk of the forward propeller is arranged at an angle of attack of α with the chord of the wing;

[0009] The control system is used to control the rudder amount of each control surface of the aircraft and the speed and direction of the forward propeller.

[0010] In this scheme, the high-speed airflow blown by the front-pull propeller flows toward the wing at an angle of attack α, produces an aerodynamic coupling lift-increasing effect with the wing, and generates a forward and upward pulling force on the aircraft; the control system is used to control the steering amount of each control surface of the aircraft and the speed and direction of each propeller; the control system controls the increase of the speed of the front-pull propeller on the front wing to tilt the fuselage backward θ and raise its head; the control system controls the speed of each front-pull motor and the lowering angle of the flaps and ailerons to balance the various directional forces on the aircraft to achieve hovering, so that the resultant force is vertically upward to achieve vertical take-off, the resultant force is vertically downward to achieve vertical landing, and the resultant force is forward to achieve level flight cruising.

[0011] According to the embodiment of the present invention, the present invention also adopts the following technical solution:

[0012] Including vertical take-off mode, vertical landing mode and hovering mode control, the control method is as follows:

[0013] The forward propellers are in working state at the same time, the forward propeller at the front of the fuselage is controlled to rotate at a higher speed than the forward propeller at the rear of the fuselage, and the fuselage is in a posture of tilting its head upward and backward, forming a tilt angle θ;

[0014] Hover mode control: Maintain the propeller thrust F 1 , wing lift F 2 The horizontal force is in equilibrium, and the propeller thrust F 1 , wing lift F 2 The sum of the vertical force components is balanced with the aircraft gravity G, which satisfies the control algorithm equation (1).

[0015] Formula (1):

[0016] F 1 sinθ+F 2 cosθ=G

[0017] F 1 cosθ=F 2 sinθ

[0018] Vertical takeoff mode control: Increase the forward propeller speed and maintain the forward propeller thrust F 1 , Wing lift F 2 The sum of the vertical force components is greater than the aircraft gravity G, which satisfies the control algorithm equation (2):

[0019] Formula (2):

[0020] F 1 sinθ+F 2 cosθ>G

[0021] F 1 cosθ=F 2 sinθ

[0022] Vertical landing mode control: reduce the speed of the forward propeller and maintain the forward propeller thrust F 1 , wing lift F 2 The horizontal force is in a balanced state, maintaining the propeller thrust F 1 , wing lift F 2 The sum of the component forces in the vertical direction is less than the aircraft's gravity G, so that the resultant force on the aircraft is vertically downward, satisfying the control algorithm equation (3).

[0023] Formula (3):

[0024] F 1 sinθ+F 2 cosθ<G

[0025] F 1 cosθ=F 2 sinθ.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] In this solution, when the aircraft is taking off and landing vertically or hovering, the front and rear propellers are adjusted to adjust the speed difference so that the fuselage tilts backward by an angle of θ. The propeller pull generates components in both the horizontal and vertical directions. At the same time, the high-speed airflow blown out by the propeller disk generates an aerodynamic coupling lift-increasing effect when flowing through the wing, thereby achieving vertical take-off and landing and hovering by closely following the propeller and the rearward tilt of the fuselage. Compared with traditional composite wing vertical take-off and landing fixed-wing aircraft, this solution completely eliminates the vertical take-off propeller power configuration, reduces the dead weight of level flight, and improves the payload capacity. In addition, compared with traditional tilt-wing vertical take-off and landing fixed-wing aircraft, this solution relies on the speed difference to achieve the tilt of the entire aircraft, without a complex power tilt structure. Therefore, the structure of the present invention is compact and simple, with large power load, high efficiency, light weight, high speed, long flight time, smooth vertical rotation, and safety and reliability.

[0028] In addition, in the present solution, no matter what flight mode the aircraft is in (vertical take-off and landing mode, level flight mode, or a transitional state between the two), the high-speed airflow from the forward-pull propeller will blow toward the wings, so that the aircraft is less affected by external meteorological conditions in each mode, less affected by airflow interference and separation, can have a smoother transition, and has better wind resistance, and can fly safely and reliably in complex terrains and complex airflow environments such as ultra-low altitudes and canyons. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the structure of a common propeller-blown-wing lift-enhancing tandem biplane aircraft in an embodiment of the present invention, wherein arrows indicate the direction of airflow during level flight.

[0030] Figure 2 Schematic diagram of the structure of a double-ducted propeller blown-wing lift-enhancing tandem biplane aircraft in an embodiment of the present invention, wherein the arrow indicates the airflow direction during level flight.

[0031] Figure 3 Schematic diagram of the structure of a single ducted propeller installed on a wing in an embodiment of the present invention, wherein the arrow indicates the direction of airflow during level flight.

[0032] Figure 4 Schematic diagram of the structure of a single-flow double-duct propeller installed on a wing in an embodiment of the present invention, wherein the arrow indicates the direction of airflow during level flight.

[0033] Figure 5 Schematic diagram of the structure in which a split-flow double-duct propeller is installed on a wing in an embodiment of the present invention, and the arrow indicates the direction of airflow during level flight.

[0034] Figure 6 This is a schematic diagram of the structure in which a divertable double-duct propeller with a baffle opened is installed on a wing in an embodiment of the present invention, and the arrow indicates the direction of airflow during level flight.

[0035] Figure 7 This is a schematic diagram of the structure of a divertable double-duct propeller with a baffle closed and installed on a wing in an embodiment of the present invention, and the arrow indicates the direction of airflow during level flight.

[0036] Figure 8 It is a schematic diagram of the airflow state when the deceleration boost gear (only set for dual ducts) is retracted in an embodiment of the present invention, and the arrow indicates the airflow direction.

[0037] Fig. 9 It is a schematic diagram of the structure of lowering the wing flaps and cooperating with the ducted propeller to lower the deceleration and boost gears during vertical take-off and landing or hovering in an embodiment of the present invention, and the arrow indicates the direction of airflow during vertical take-off and landing or hovering.

[0038] Fig.10 This is a schematic diagram of a propeller-blown wing-enhanced lift multi-wing aircraft according to an embodiment of the present invention, in which the fuselage of the aircraft is tilted up and backward by an angle θ during vertical take-off and landing or hovering, and the arrow indicates the direction of airflow during vertical take-off and landing or hovering.

[0039] Fig.11 Schematic diagram of force analysis during hovering in an embodiment of the present invention.

[0040] Fig.12 It is a schematic diagram of force analysis during vertical takeoff in an embodiment of the present invention.

[0041] Fig.13 Schematic diagram of force analysis during vertical landing in an embodiment of the present invention.

[0042] Fig.14 It is a schematic diagram of force analysis during level flight in an embodiment of the present invention.

[0043] In the figure: 1. Fuselage; 2. Wing; 3. Front-pull propeller; 4. Propeller; 5. Motor; 6. Plano-convex duct; 7. U-shaped curved body; 8. Upward convex wing surface; 9. Flaps; 10. Ailerons; 11. Landing gear; 12. Baffle; 13. Speed ​​reduction and boost gear; 14. Duct; 15. Front-pull ducted propeller. DETAILED DESCRIPTION

[0044] The present invention is further described in detail below with reference to the accompanying drawings, and four specific implementation methods are given.

[0045] like Figure 1 , 2 As shown, a propeller-blown-wing lift-enhancing multi-wing aircraft comprises a fuselage 1, wings 2, a control system, a landing gear, and a front-pull propeller 3. The wings 2 are at least two rows, and each row of wings 2 is composed of left and right wings 2 symmetrically distributed on both sides of the fuselage 1. Each row of wings 2 is distributed on the fuselage 1 in a symmetrical manner along the axis of the fuselage 1 according to the moment of gravity of the aircraft center;

[0046] There are multiple front propellers 3, each of which is installed at the front lower part of the wing 2. The center line T of the propeller disk of the front propeller 3 is arranged at an angle of attack α with the chord A of the wing 2; the angle α is 0-20°

[0047] The control system is used to control the steering amount of each control surface of the aircraft and the speed and direction of the forward propeller 3.

[0048] In this scheme, if Figure 3 As shown, the high-speed airflow blown by the front-pull propeller 3 flows toward the wing 2 at an angle of attack α, and produces an aerodynamic coupling lift-increasing effect with the wing 2, generating a forward and upward pulling force on the aircraft; the control system is used to control the steering amount of each control surface of the aircraft and the speed and direction of each propeller; the control system controls the increase of the speed of the front-pull propeller 3 on the front wing 2, so that the fuselage 1 tilts backward θ and raises its head (see Fig.10 ), the control system controls the rotation speed of each forward pulling motor and the lowering angle of the flap 9 and the aileron 10, so that the various forces acting on the aircraft are balanced to achieve hovering, the resultant force is made vertically upward to achieve vertical take-off, the resultant force is made vertically downward to achieve vertical landing, and the resultant force is made forward to achieve level flight cruising.

[0049] The wing 2 located in the front row of the fuselage 1 is a conventional wing 2 or a canard, and the wing 2 located in the rear row of the fuselage 1 is any one of a conventional wing 2, a canard or a rear flat winglet; the rear flat winglet is a small flat wing installed at the rear of the fuselage 1, and the size of the rear flat winglet is smaller than that of the wing 2. The rear flat winglet is mainly used to adjust the attitude of the aircraft and can also generate some lift.

[0050] Example 1

[0051] like Figure 1 As shown, the front-pull propeller 3 is a front-pull common propeller, which includes a device composed of a propeller 4 and a motor 5. The wings 2 are in two rows, and the two rows of wings 2 are arranged along the axis of the fuselage 1 and are distributed at both ends of the center of gravity of the fuselage 1 in a moment-symmetrical manner. The rotation speed of the front-pull propeller 3 on the front-row wing 2 is increased, so that the fuselage 1 tilts backward by θ and raises its head. The rotation speed of each front-pull propeller 3 and the lowering angle of the flap 9 and the aileron 10 are controlled by the control system to balance the various directional forces on the aircraft to achieve hovering, so that the resultant force is vertically upward to achieve vertical take-off, the resultant force is vertically downward to achieve vertical landing, and the resultant force is forward to achieve level flight cruising.

[0052] Example 2

[0053] like Figure 2 As shown, the front-pull propeller is a front-pull ducted propeller 15; the front-pull ducted propeller 15 is formed by wrapping a front-pull ordinary propeller with a duct 14. That is, the propeller 4 and the motor 5 are wrapped by the duct.

[0054] The front-pull ducted propeller 15 is any one or a combination of a single-ducted propeller and a double-ducted propeller. The single-ducted propeller is composed of a ducted propeller 4 and a motor 5. Figure 2 , 4 As shown, the double-ducted propeller is composed of a single-ducted propeller and a plano-convex duct 6 connected in series, and the plano-convex duct 6 is composed of an inverted U-shaped curved body 7 and a corresponding upper convex wing surface 8 of the wing 2, extending from the leading edge of the wing 2 to the upper wing surface of the wing 2. The high-speed airflow blown by the front-pull propeller 3 flows from the front single duct to the rear plano-convex duct 6, and generates lift through aerodynamic coupling with the plano-convex duct 6.

[0055] The top of the duct of the front-pull ducted propeller 3 is in a parallel surface shape or an upward convex surface shape along the airflow direction. When the top of the duct is in an upward convex surface shape along the airflow direction, aerodynamic lift similar to that of a wing can be generated when the airflow flows through the upper convex surface during flight, thereby improving the aerodynamic efficiency of the aircraft.

[0056] The single-ducted propeller is directly connected to the plano-convex duct 6 or connected through a conduit; the single-ducted propeller connected to the plano-convex duct 6 through a conduit can be arranged at any position of the aircraft; a single-ducted propeller can be connected to one or more plano-convex ducts 6 through a conduit.

[0057] In addition, the double-duct propeller is any one of a single-flow double-duct propeller, a split double-duct propeller, and a split double-duct propeller. The connection between the front and rear ducts of the single-flow double-duct propeller is completely sealed, and the airflow flowing through the front duct all flows into the rear flat-convex duct 6; the connection between the front and rear ducts of the split double-duct propeller is provided with an opening, and the airflow flowing through the front duct is split, with one part flowing into the rear flat-convex duct 6, and the other part flowing from the opening of the connection to the lower wing surface of the wing 2; the connection between the front and rear ducts of the split double-duct propeller is provided with an opening, and an openable and closable baffle 12 is provided at the opening. When the baffle 12 is opened, the airflow flowing through the front duct is split, with one part flowing into the rear flat-convex duct 6, and the other part flowing from the opening of the connection to the lower wing surface of the wing 2; when the baffle 12 is closed, the airflow flowing through the front duct all flows into the rear flat-convex duct 6.

[0058] The tail upper end of the flat-convex duct 6 of the double-duct propeller is connected with a deceleration and boosting tooth 13, and the deceleration and boosting tooth 13 is provided with one or more teeth, which are distributed along the airflow direction of the flat-convex duct 6. When the deceleration and boosting tooth 13 is lowered, the airflow is decelerated and boosted to increase lift; when the deceleration and boosting tooth 13 is retracted, the airflow is accelerated to reduce resistance, see Figure 8 and Fig. 9 , respectively showing the high-speed airflow blown by the ducted propeller to the upper wing surface and the high-speed airflow blown by the ducted propeller to the lower wing surface after the deceleration booster gear 13 is folded or lowered.

[0059] like Figure 1 , 2 As shown in FIGS. 10 and 11 , the wing 2 includes a wing 2 body, a flap 9 and an aileron 10 movably connected to the wing 2 body; the flap 9 is any one or a combination of a leading edge flap 9, a leading edge slat, and a trailing edge flap 9. The magnitude and direction of the lift and drag of the wing 2 can be adjusted by adjusting the lowering angle of the flap 9.

[0060] Including vertical take-off mode, vertical landing mode and hovering mode control, the control method is as follows:

[0061] The forward propeller 3 is in working state at the same time, and the forward propeller 3 at the front of the fuselage 1 is controlled to rotate at a higher speed than the forward propeller 3 at the rear of the fuselage 1, so that the fuselage 1 is in a posture of tilting its head and backward, forming a tilt angle θ;

[0062] Hover mode control: Keep the propellers pulled forward at 3 F 1 、Wing 2 lift F 2 The force in the horizontal direction is in a state of equilibrium, and the sum of the thrust of the front propeller 3 and the lift of the wing 2 in the vertical direction is balanced with the aircraft gravity G, see Fig.11 ; That is, the control algorithm equation (1) is satisfied:

[0063] Formula (1):

[0064] F 1 sinθ+F 2 cosθ=G

[0065] F 1 cosθ=F 2 sinθ

[0066] Vertical takeoff mode control: Increase the speed of the forward propeller 3 and maintain the thrust F of the forward propeller 3 1 、Wing 2 lift F 2 The sum of the vertical forces is greater than the aircraft's gravity G, see Fig.12 ; That is, the control algorithm equation (2) is satisfied:

[0067] Formula (2):

[0068] F 1 sinθ+F 2 cosθ>G

[0069] F 1 cosθ=F 2 sinθ

[0070] Vertical landing mode control: reduce the speed of the forward propeller 3 and maintain the thrust F of the forward propeller 3 1 、Wing 2 lift F 2 The horizontal force is in a balanced state, and the propeller is kept pulling forward with a force F 1 、Wing 2 lift F 2 The sum of the vertical force components is less than the aircraft's gravity G, so that the resultant force on the aircraft is vertically downward. Fig.13 , satisfying the control algorithm equation (3).

[0071] Formula (3):

[0072] F 1 sinθ+F 2 cosθ<G

[0073] F 1 cosθ=F 2 sinθ

[0074] It also includes a level flight transition mode control, and the level flight transition mode control method is as follows:

[0075] The front and rear propellers 3 of the fuselage 1 are controlled to gradually reach the same speed, so that the fuselage 1 is gradually adjusted to a horizontal posture; the flaps 9 are controlled to be gradually retracted, and the speed of the front propellers 3 is increased at the same time, so that the resultant force on the aircraft is forward. That is, the lift F of the wing 2 2 The aircraft's gravity G is balanced, and the propeller is pulled forward with a force F of 3 1 Greater than air resistance F3 See also Fig.14 , which satisfies formula (4).

[0076] Formula (4):

[0077] F 2 =G

[0078] F >F 3

[0079] When the aircraft needs to hover, the front propellers 3 on the wing 2 work at the same time, the front propellers 3 generate a forward pulling force, and the high-speed airflow blown out by the front propellers 3 flows through the wing 2 to generate an aerodynamic coupling lift-increasing effect. The control system adjusts the speed of the front propellers 3 at the front of the fuselage 1 to be higher than the front propellers 3 at the rear of the fuselage 1, so that the fuselage 1 lifts up and tilts backward by an angle of θ. At the same time, the control system adjusts the speed of each propeller so that the pulling force of the front propellers 3 and the lift force of the wing 2 in the horizontal direction offset each other and balance each other, so that the front propellers 3, the sum of the vertical components of the wing 2 lift and the gravity balance, so that the various forces on the aircraft are offset and balanced, and then the aircraft can hover; increase the throttle or switch, increase the speed of each propeller through the control system to make the resultant force on the aircraft vertically upward, so that the aircraft can take off vertically; reduce the throttle or switch, reduce the speed of each propeller through the control system to make the resultant force on the aircraft vertically downward, so that the aircraft can land vertically; the fuselage 1 tilts up and tilts backward at an angle θ less than 45°, generally controlled at 10° to 30°. When the aircraft needs to transition to the level flight mode, gradually control the speed of the front and rear propellers of the fuselage 1 to converge (gradually reach the same speed state), so that the fuselage 1 gradually returns to the horizontal, and at the same time gradually retracts the flaps 9, adjusts the speed of each propeller through the control system to make the resultant force on the aircraft forward, pulls the aircraft forward and accelerates to the cruising speed, and the aircraft enters the level flight mode.

[0080] To sum up, both rows of wings 2 of the fuselage 1 can adopt conventional wings 2, or the front row of the fuselage 1 can be a combination of canards and the rear row of the fuselage 1 can be a combination of conventional wings 2, or the front row of the fuselage 1 can be a combination of conventional wings 2 and the rear row of the fuselage 1 can be a combination of, or the front row of the fuselage 1 can be a combination of conventional wings 2 and the rear row of the fuselage 1 can be a combination of rear flat wings.

[0081] The aircraft's pitch, front and rear translation, left and right translation, roll, and rotation maneuver control is achieved by adjusting the speed difference between the front and rear rows of forward-pushing propellers 3 to enable the aircraft to achieve pitch maneuvers and front and rear translation maneuvers; adjusting the left and right aileron deflection angle difference to achieve left and right translation maneuvers; adjusting the left and right forward-pushing propeller speed difference to achieve the aircraft's roll and rotation maneuvers.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A propeller-blown wing-lift multi-wing aircraft, comprising a fuselage, wings, a control system and a front-pull propeller, characterized in that: The wings include multiple rows, each row of wings is composed of left and right wings symmetrically distributed on both sides of the fuselage; the multiple rows of wings are arranged on the fuselage in a symmetrical manner along the fuselage axis according to the moment of gravity of the aircraft center; There are multiple forward propellers, each of which is installed at the front lower part of the wing, and the center line of the propeller disk of the forward propeller is arranged at an angle of attack of α with the chord of the wing; The control system is used to control the rudder amount of each control surface of the aircraft and the speed and direction of the forward propeller.

2. The propeller-blown-wing lift-enhancing multi-wing aircraft according to claim 1, characterized in that: The wing located at the front row of the fuselage is a conventional wing or a canard, and the wing located at the rear row of the fuselage is any one of a conventional wing, a canard or a rear flat winglet; the rear flat winglet is a small flat wing installed at the rear of the fuselage, and the size of the rear flat winglet is smaller than the size of the wing.

3. The propeller-blown-wing lift-enhancing multi-wing aircraft according to claim 1, characterized in that: The front-pull propeller is a front-pull ordinary propeller or a front-pull ducted propeller. The front-pull ordinary propeller includes a propeller and a motor; the front-pull ducted propeller is formed by wrapping the front-pull ordinary propeller with a duct.

4. The propeller-blown-wing high-lift multi-wing aircraft according to claim 3, characterized in that: The front-pull ducted propeller is any one or a combination of a single-ducted propeller and a double-ducted propeller. The single-ducted propeller is composed of a duct wrapping a propeller and a motor, and the double-ducted propeller is composed of a single-ducted propeller and a plano-convex duct in series. The plano-convex duct is composed of an inverted U-shaped curved surface and the corresponding upper convex wing surface, extending from the leading edge of the wing to the upper wing surface of the wing.

5. The propeller-blown-wing high-lift multi-wing aircraft according to claim 4, characterized in that: The double-duct propeller is any one of a single-flow double-duct propeller, a split double-duct propeller, and a split double-duct propeller. The connection between the front and rear ducts of the single-flow double-duct propeller is completely sealed, and the airflow flowing through the front duct all flows into the rear flat-convex duct; the connection between the front and rear ducts of the split double-duct propeller is provided with an opening, and the airflow flowing through the front duct is split, with one part flowing into the rear flat-convex duct and the other part flowing from the opening of the connection to the lower wing surface of the wing; the connection between the front and rear ducts of the split double-duct propeller is provided with an opening, and an openable and closable baffle is provided at the opening. When the baffle is opened, the airflow flowing through the front duct is split, with one part flowing into the rear flat-convex duct and the other part flowing from the opening of the connection to the lower wing surface of the wing; when the baffle is closed, the airflow flowing through the front duct all flows into the rear flat-convex duct.

6. The propeller-blown-wing high-lift multi-wing aircraft according to claim 4, characterized in that: The single-duct propeller is connected to the plano-convex duct directly or through a conduit.

7. The propeller-blown-wing high-lift multi-wing aircraft according to claim 5, characterized in that: The tail upper end of the plano-convex duct of the double-duct propeller is connected with a deceleration and boosting tooth, and the deceleration and boosting tooth is provided with one or more and distributed along the airflow direction of the plano-convex duct.

8. The propeller-blown-wing high-lift multi-wing aircraft according to claim 4, characterized in that: The duct top of the forward-pull ducted propeller is in a parallel surface shape or an upward convex surface shape along the airflow direction.

9. The propeller-blown-wing high-lift multi-wing aircraft according to claim 1, characterized in that: The angle α is in the range of 0° to 20°.

10. The propeller-blown-wing high-lift multi-wing aircraft according to claim 1, characterized in that: The wing comprises a wing body and flaps and ailerons movably connected to the wing body; the flap is any one or a combination of a leading edge flap, a leading edge slat, and a trailing edge flap.

11. The control method of a propeller-blown-wing high-lift multi-wing aircraft according to any one of claims 1 to 10, characterized in that: Including vertical take-off mode, vertical landing mode and hovering mode control, the control method is as follows: The forward propellers are in working state at the same time, the forward propeller at the front of the fuselage is controlled to rotate at a higher speed than the forward propeller at the rear of the fuselage, and the fuselage is in a posture of tilting backward with its head up, forming a tilt angle θ; Hovering mode control: Keep the horizontal components of the propeller thrust F1 and the wing lift F2 in a balanced state, and the sum of the vertical components of the propeller thrust F1 and the wing lift F2 is balanced with the aircraft gravity G, that is, satisfying the control algorithm equation (1): Formula (1): F1 sinθ+F2 cosθ=G F1 cosθ=F2 sinθ Vertical takeoff mode control: Increase the forward propeller speed to keep the sum of the forward propeller thrust F1 and the wing lift F2 in the vertical direction greater than the aircraft gravity G, that is, satisfy the control algorithm equation (2): Formula (2): F1 sinθ+F2 cosθ>G F1 cosθ=F2 sinθ Vertical landing mode control: reduce the speed of the front propeller, keep the horizontal components of the front propeller thrust F1 and the wing lift F2 in a balanced state, keep the sum of the vertical components of the front propeller thrust F1 and the wing lift F2 less than the aircraft gravity G, so that the resultant force on the aircraft is vertically downward, satisfying the control algorithm equation (3). Formula (3): F1 sinθ+F2 cosθ<G F1 cosθ=F2 sinθ.

12. The control method of the propeller-blown-wing high-lift multi-wing aircraft according to claim 11, characterized in that: It also includes a level flight transition mode control, and the level flight transition mode control method is as follows: The speed of the front and rear propellers of the fuselage is controlled to gradually reach the same speed state, so that the fuselage is gradually adjusted to a horizontal posture; the flaps are controlled to be gradually retracted, and the speed of the front propellers is increased at the same time, so that the resultant force acting on the aircraft is forward.

13. The control method of the propeller-blown-wing high-lift multi-wing aircraft according to claim 11, characterized in that: The tilt angle θ is less than 45°.

14. The control method of the propeller-blown-wing high-lift multi-wing aircraft according to claim 13, characterized in that: The tilt angle θ is between 10° and 30°.

15. The control method of the propeller-blown-wing high-lift multi-wing aircraft according to claim 11, characterized in that: It also includes the pitch, front and rear translation, left and right translation, roll, and rotation maneuver control of the aircraft, adjusting the speed difference between the front and rear rows of forward-pushing propellers to enable the aircraft to achieve pitch maneuvers and front and rear translation maneuvers; adjusting the left and right aileron deflection angle difference to achieve left and right translation maneuvers; adjusting the left and right forward-pushing propeller speed difference to achieve rolling and rotation maneuvers of the aircraft.

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