A blow wing vertical take-off and landing fixed-wing aircraft and a control method thereof

Abstract

This invention discloses a blown-wing vertical takeoff and landing (VTOL) fixed-wing aircraft and its control method, belonging to the field of aircraft technology. It includes a fuselage, main wing, retractable wing, tail-mounted tilting electric duct, and a control system. The fuselage has a built-in pressurized duct and an air intake at the front. An array of nozzles is arranged on the upper surface of the main wing and connected to the pressurized duct. The retractable wing is mounted on the trailing edge of the main wing. Symmetrically arranged tail-mounted electric ducts capable of vertical / horizontal tilting are located at the tail. The entire aircraft has no exposed rotating blades. During VTOL, the retractable wing deploys, and the pressurized duct supplies air to the array of nozzles, generating primary lift through the Coanda effect. The retractable wing guides air to generate secondary lift, and the tail-mounted duct provides vertical thrust for auxiliary lift and attitude adjustment. During level flight, the retractable wing retracts, and the tail-mounted duct provides horizontal rearward cruise thrust. This invention achieves smooth switching between VTOL, transitional flight, and level flight cruise through its control method, making it suitable for emergency rescue and low-altitude operations in complex terrain scenarios.

Description

Technical Field

[0001] This invention relates to the field of aircraft technology, and in particular to a blown-wing vertical takeoff and landing fixed-wing aircraft and its control method. Background Technology

[0002] With the rapid growth in demand for urban air traffic, emergency rescue, and operations in complex terrain, vertical takeoff and landing (VTOL) aircraft have become a research hotspot in the aviation field due to their advantages of not requiring long runways and their strong adaptability to different terrains. Traditional VTOL aircraft are mainly divided into two categories: multi-rotor aircraft and tiltrotor aircraft. Multi-rotor aircraft rely on exposed high-speed rotating blades to provide lift, which has drawbacks such as low cruising speed, short range, and limited payload capacity. Furthermore, the exposed blades are prone to collisions with obstacles or people in complex terrain and densely populated areas, resulting in insufficient safety. While tiltrotor aircraft can combine the advantages of VTOL and fixed-wing cruise, they have complex structures, high reliability requirements, and face problems such as aerodynamic interference and control difficulties during mode switching. At the same time, the exposed rotors still pose safety hazards, making it difficult to meet the operational needs in complex environments.

[0003] Blown-wing aircraft generate lift by ejecting high-speed airflow onto the upper surface of their wings, utilizing the Coanda effect and airflow adhesion to the walls. They offer advantages such as high lift efficiency and relatively simple structure. However, existing blown-wing vertical takeoff and landing (VTOL) aircraft generally suffer from a single lift source, fixed lift area, and high cruise drag. Some designs still retain exposed power components, leading to insufficient safety in complex terrain operations and limitations in payload capacity and range for practical applications. Furthermore, most existing blown-wing aircraft lack adjustable aerodynamic structures designed for the different needs of vertical takeoff and landing and level flight cruise, resulting in poor smoothness during mode switching, further limiting their application scenarios. Therefore, there is an urgent need to develop a new type of blown-wing VTOL aircraft that combines the flexibility of vertical takeoff and landing, the high-speed cruise efficiency of fixed-wing aircraft, and high safety. Summary of the Invention

[0004] The purpose of this invention is to provide a blown-wing vertical takeoff and landing fixed-wing aircraft and its control method. It achieves efficient main lift generation through built-in pressurized duct and wing array nozzles, generates secondary lift in conjunction with retractable wings, and achieves attitude adjustment and cruise thrust by combining a tail-mounted tiltable electric duct.

[0005] To achieve the above objectives, the present invention provides a blown-wing vertical takeoff and landing fixed-wing aircraft, comprising a fuselage, a main wing, a retractable wing, a tail tilting electric duct, and a control system; the fuselage integrates a pressurized duct and has an air inlet at the front of the fuselage connected to the air inlet of the pressurized duct; the main wing is fixedly connected to both sides of the fuselage, and its upper surface has multiple array nozzles arranged along the spanwise direction, the array nozzles being connected to the air outlet of the pressurized duct through the internal air passage of the main wing; the retractable wing is symmetrically mounted on both sides of the fuselage and located at the trailing edge of the main wing; the tail tilting electric duct is symmetrically located on both sides of the tail of the fuselage and is connected to a tilting mechanism through a duct mounting base, realizing tilting between the vertically downward direction and the horizontally rearward direction; the control system is electrically connected to the pressurized duct, the retractable wing, and the tail tilting electric duct respectively.

[0006] Preferably, the pressurization duct is equipped with a pressurization fan or compressor.

[0007] Preferably, the array nozzle is a fixed nozzle structure, and the nozzle is set close to the surface of the main wing, with the jet direction parallel to the wing surface.

[0008] Preferably, the telescopic wing is a multi-stage telescopic wing structure, with adjacent winglets connected by telescopic slide rails or telescopic hinges, and driven by an electric push rod integrated inside the fuselage.

[0009] Preferably, the tilting mechanism includes a lateral rotating shaft and a tilting motor. The axis of the lateral rotating shaft is parallel to the spanwise direction of the main airframe, and one end of the lateral rotating shaft is connected to the duct mounting base, while the other end passes through the tail housing of the fuselage and is connected to the output shaft of the tilting motor. The tilting motor is integrated inside the fuselage. The blades of the tail tilting electric duct are completely enclosed inside the duct housing.

[0010] Preferably, the control system includes a flight controller, attitude sensors, pressure sensors, and actuators, all of which are integrated inside the fuselage.

[0011] This invention also includes a control method for a blown-wing vertical takeoff and landing fixed-wing aircraft, comprising three modes of switching control: Vertical takeoff and landing phase: Control the telescopic wings to fully extend, activate the pressurized duct to make the array nozzles spray air at high speed, and control the tail tilting electric duct to tilt to the vertical downward direction, so that the aircraft can take off or land vertically. Transitional flight phase: As the forward speed of the aircraft increases, the retractable wings are gradually controlled to retract inward, and the tail tilting electric duct is simultaneously controlled to tilt from vertical downward to horizontal and backward, while the air supply flow of the pressurized duct is gradually adjusted. Level flight cruise phase: Control the retractable wings to fully retract, tilt the tail duct to the horizontal rearward direction, and cruise in fixed-wing mode.

[0012] Preferably, during the transition flight phase, the blown air lift gradually decreases while the fixed-wing aerodynamic lift gradually builds up, achieving a smooth switch of lift sources.

[0013] Preferably, during the level flight cruise phase, the jet flow rate of the array nozzles is opened or adjusted according to cruise requirements to help increase wing lift or delay airflow separation to prevent stall.

[0014] Preferably, during the vertical landing phase, the aircraft is controlled to decelerate, the tail tilting electric duct tilts upward to the vertical downward direction, the telescopic wings are re-deployed, the pressurized duct increases the air supply flow, and the blow-up lift and secondary lift working state is restored to achieve vertical landing or high angle of attack landing.

[0015] Therefore, the present invention employs the above-mentioned blown-wing vertical takeoff and landing fixed-wing aircraft and its control method, which has the following technical effects: (1) The present invention generates main lift by jetting air close to the wing surface through array nozzles, and generates secondary lift by guiding airflow with telescopic wings. Combined with tail tilting electric duct auxiliary lift, the total lift efficiency is significantly higher than that of traditional fixed-wing and multi-rotor aircraft, and can support larger loads and shorter take-off and landing distances.

[0016] (2) The present invention can realize the smooth switching between vertical take-off and landing, short take-off and landing and high-speed cruise, and has both site adaptability and cruise efficiency, and is suitable for complex scenarios such as cities, mountains, and disaster sites.

[0017] (3) The telescopic wing of the present invention retracts during level flight, which greatly reduces aerodynamic drag. Combined with the lightweight structural design, it significantly improves the payload capacity and range of the aircraft.

[0018] (4) The tail tiltable electric duct of the present invention can provide precise attitude control thrust, and achieve pitch and yaw adjustment through thrust difference, effectively solving the stability problem in the vertical take-off and landing and mode switching stages.

[0019] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0020] Figure 1 This is a three-dimensional wireframe diagram of a blow-wing type vertical take-off and landing fixed-wing aircraft in vertical take-off and landing mode according to the present invention. Figure 2 This is a three-dimensional wireframe diagram of a blown-wing vertical takeoff and landing fixed-wing aircraft in level flight cruise mode according to the present invention. Figure 3 This is a structural diagram of the high-pressure blowing system in a blown-wing vertical takeoff and landing fixed-wing aircraft according to the present invention; Figure 4This is a top view of a blow-wing type vertical take-off and landing fixed-wing aircraft according to the present invention; Figure 5 This is a schematic diagram of the structure of a blown-wing vertical take-off and landing fixed-wing aircraft according to the present invention; Figure 6 This invention relates to a blown-wing vertical takeoff and landing fixed-wing aircraft. Figure 5 Enlarged view of point A in the middle.

[0021] Figure 7 This is a schematic diagram of the telescopic wing structure in a blown-wing vertical take-off and landing fixed-wing aircraft according to the present invention.

[0022] Figure Labels 1. Electric duct; 2. Duct mounting base; 3. Telescopic wing; 31. Electric push rod; 4. Main wing; 5. Internal air passage; 6. Pressurized duct; 7. Air inlet; 8. Array nozzles; 9. Fuselage; 10. Lateral pivot; 11. Vertical tail; 12. Horizontal tail; 13. Tilting motor. Detailed Implementation

[0023] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0025] like Figures 1 to 7 As shown, a blown-wing vertical takeoff and landing fixed-wing aircraft includes a fuselage 9, a main wing 4, a telescopic wing 3, a tail tilting electric duct 1, and a control system.

[0026] The fuselage 9 is integrally molded from lightweight, high-strength composite materials, with symmetrical air inlets 7 on the front left and right sides. These inlets 7 connect inwards to the intake end of the pressurization duct 6. The pressurization duct 6 houses a pressurization fan or compressor, powered by the onboard power supply. During operation, air is drawn in from the outside, pressurized, and then passed through the internal air passages 5 of the main wing 4 before being delivered to the array nozzles 8, providing power for airflow boosting.

[0027] The main wing 4 adopts a straight wing or slightly swept wing layout and is fixedly connected to both sides of the fuselage 9. Multiple rows of array nozzles 8 are arranged along the span of the upper surface of the main wing 4. The array nozzles 8 are fixed nozzle structures with no moving parts. The nozzles are set close to the surface of the main wing 4, and the jet direction is parallel to the wing surface to ensure that the airflow adheres to the wing surface and forms a stable Coanda effect, maximizing the lift coefficient.

[0028] The retractable wing 3 is a multi-stage retractable wing structure. Adjacent winglets are connected by retractable slide rails. The nose winglet is connected to the output end of the electric push rod 31, which is integrated into the fuselage 9. During vertical takeoff and landing, it is fully deployed to receive the high-speed airflow at the trailing edge of the main wing 4 and force it to deflect downward, generating secondary lift. During level flight, it retracts inward, fitting against the trailing edge of the main wing 4 or being stored inside, reducing the wingspan and frontal area, and lowering aerodynamic drag.

[0029] The tail tilting electric duct 1 is symmetrically arranged on both sides of the tail of the fuselage 9 and connected to the tilting mechanism through the duct mounting base 2. The tilting mechanism includes a transverse rotating shaft 10 and a tilting motor 13. The axis of the transverse rotating shaft 10 is parallel to the spanwise direction of the main wing 4. One end of the transverse rotating shaft 10 is connected to the duct mounting base 2, and the other end passes through the tail shell of the fuselage 9 and is connected to the output shaft of the tilting motor 13. The tilting motor 13 is integrated inside the fuselage 9, enabling the tail tilting electric duct 1 to tilt between vertically downward and horizontally backward. The blades of the tail tilting electric duct 1 are completely enclosed inside the duct shell, with no exposed rotating parts, eliminating the risk of exposed collisions.

[0030] The control system includes a flight controller, attitude sensors, pressure sensors, and actuators, all integrated within the fuselage 9. The control system is electrically connected to the pressurized duct 6, the retractable wing 3, and the tail tilt-electric duct 1, respectively. It collects flight attitude, air pressure, and speed signals in real time, automatically adjusting the air supply to the pressurized duct 6, the extension / retraction state of the retractable wing 3, and the tilt angle and thrust of the tail tilt-electric duct 1 to achieve full-mode automated control.

[0031] A control method for a blown-wing vertical takeoff and landing fixed-wing aircraft, based on the aforementioned aircraft, includes three modes of switching control: Vertical takeoff and landing phase: During vertical takeoff, the control system fully deploys the retractable wing 3 to maximize lift area. The supercharged duct 6 operates at full power, drawing in air from the intake 7. After pressurization, the air is expelled at high speed through the array nozzles 8, creating a low-pressure zone on the upper surface of the main wing 4, generating primary lift. The high-speed airflow, after passing the trailing edge of the main wing 4, acts on the fully deployed retractable wing 3, which guides the airflow significantly downwards, generating secondary lift. Simultaneously, the control system tilts the tail-mounted electric duct 1 to a vertically downward direction, outputting vertical thrust to provide auxiliary lift. The thrust difference between the left and right ducts achieves pitch and yaw attitude balance and adjustment. The total lift of the aircraft consists of three parts: primary lift from the wing surfaces, secondary lift from the retractable wing 3, and vertical thrust from the tail duct. This total lift overcomes gravity to achieve vertical takeoff. During hovering, attitude stability is maintained by adjusting the total thrust and differential thrust. The entire aircraft has no exposed rotating parts, ensuring high safety.

[0032] During vertical landing, the aircraft decelerates, the tail tilting electric duct 1 tilts upward to the vertical downward direction, the telescopic wing 3 re-deploys, the pressurization duct 6 increases the air supply flow, and the blow-up lift and secondary lift working state are restored to achieve vertical landing or high angle of attack landing.

[0033] Transitional flight phase: As forward speed increases, the fixed-wing aerodynamic lift gradually builds up. The control system gradually reduces the blown air flow, controlling the retractable wing 3 to slowly retract inward, and simultaneously controlling the tail tilting electric duct 1 to tilt from vertically downward to horizontally and rearward, transitioning the thrust direction from vertical to horizontal. During this process, the blown air lift gradually decreases, and the fixed-wing aerodynamic lift gradually builds up, achieving a smooth switch of lift source. The transition process is stable, with no risk of interference from exposed components.

[0034] Level flight cruise phase: Once the aircraft enters level flight cruise, the control system fully retracts the telescopic wing 3, significantly reducing the frontal area and aerodynamic drag. The tail tilt-type electric duct 1 tilts to a horizontal rearward direction, outputting forward thrust, becoming the main power source for the aircraft's cruise. At this time, the aircraft cruises at high speed in fixed-wing mode, achieving high aerodynamic efficiency, low energy consumption, and a significantly increased range. The aircraft's directional stability and maneuverability are provided by the vertical tail 11, while pitch stability and maneuverability are provided by the horizontal tail 12, consistent with the control principles of conventional fixed-wing aircraft. Furthermore, the tilt-type duct can provide additional vector roll control. In cruise mode, the jet flow of the array nozzles 8 can be opened or adjusted according to cruise requirements to assist in increasing wing lift or delaying airflow separation to prevent stall. When the aircraft encounters severe wind shear, the wing-blown lift enhancement device can be quickly activated to delay airflow separation on the wing surface and prevent stall.

[0035] Because the aircraft has no exposed rotating parts, it is less likely to collide with propellers when flying near obstacles such as mountains, forests, ruins, and building components, which greatly improves the safety of low-altitude operations and use in complex environments.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A blown-wing vertical takeoff and landing fixed-wing aircraft, characterized in that: The system includes a fuselage, main wings, retractable wings, a tail tilting electric duct, and a control system. The fuselage integrates a pressurized duct, and the front of the fuselage has an air intake connected to the pressurized duct's air intake. The main wings are fixedly connected to both sides of the fuselage, and their upper surfaces have multiple array nozzles arranged along the spanwise direction. These array nozzles are connected to the pressurized duct's air outlet through internal air passages in the main wings. The retractable wings are symmetrically mounted on both sides of the fuselage, located at the trailing edge of the main wings. The tail tilting electric duct is symmetrically located on both sides of the tail of the fuselage and connected to a tilting mechanism via a duct mounting base, enabling tilting between the vertically downward direction and the horizontally rearward direction. The control system is electrically connected to the pressurized duct, the retractable wings, and the tail tilting electric duct.

2. The blown-wing vertical takeoff and landing fixed-wing aircraft according to claim 1, characterized in that: The pressurization duct is equipped with a pressurization fan or air compressor.

3. The blown-wing vertical takeoff and landing fixed-wing aircraft according to claim 1, characterized in that: The array nozzles are fixed nozzle structures, and the nozzles are set close to the surface of the main wing, with the jet direction parallel to the wing surface.

4. A blown-wing vertical takeoff and landing fixed-wing aircraft according to claim 1, characterized in that: The telescopic wing is a multi-stage telescopic wing structure, with adjacent winglets connected by telescopic slide rails or telescopic hinges and driven by an electric push rod integrated inside the fuselage.

5. A blown-wing vertical takeoff and landing fixed-wing aircraft according to claim 1, characterized in that: The tilting mechanism includes a lateral rotating shaft and a tilting motor. The axis of the lateral rotating shaft is parallel to the span of the main airframe, and one end of the lateral rotating shaft is connected to the duct mounting base, while the other end passes through the tail shell of the fuselage and is connected to the output shaft of the tilting motor. The tilting motor is integrated inside the fuselage. The blades of the tail tilting electric duct are completely enclosed inside the duct shell.

6. A blown-wing vertical takeoff and landing fixed-wing aircraft according to claim 1, characterized in that: The control system includes a flight controller, attitude sensors, pressure sensors, and actuators, all of which are integrated inside the fuselage.

7. A control method for a blown-wing vertical takeoff and landing fixed-wing aircraft, based on the aircraft described in any one of claims 1-6, characterized in that, Includes three mode switching controls: Vertical takeoff and landing phase: Control the telescopic wings to fully extend, activate the pressurized duct to make the array nozzles spray air at high speed, and control the tail tilting electric duct to tilt to the vertical downward direction, so that the aircraft can take off or land vertically. Transitional flight phase: As the forward speed of the aircraft increases, the retractable wings are gradually controlled to retract inward, and the tail tilting electric duct is simultaneously controlled to tilt from vertical downward to horizontal and backward, while the air supply flow of the pressurized duct is gradually adjusted. Level flight cruise phase: Control the retractable wings to fully retract, tilt the tail duct to the horizontal rearward direction, and cruise in fixed-wing mode.

8. The control method for a blown-wing vertical takeoff and landing fixed-wing aircraft according to claim 7, characterized in that: During the transitional flight phase, the blown air lift gradually decreases, while the fixed-wing aerodynamic lift gradually builds up, achieving a smooth switch of lift sources.

9. The control method for a blown-wing vertical takeoff and landing fixed-wing aircraft according to claim 7, characterized in that: During the level flight cruise phase, the jet flow of the array nozzles is opened or adjusted according to cruise requirements to help increase wing lift or delay airflow separation to prevent stall.

10. The control method for a blown-wing vertical takeoff and landing fixed-wing aircraft according to claim 7, characterized in that: During the vertical landing phase, the aircraft is controlled to decelerate, the tail tilting electric duct tilts upward to the vertical downward direction, the telescopic wings are re-deployed, the pressurized duct increases the air supply flow, and the blow-up lift and secondary lift operation is restored to achieve vertical landing or high angle of attack landing.

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