Electric short-distance take-off and landing double-wing aircraft

Abstract

The invention relates to an electric short-distance take-off and landing double-wing aircraft which comprises an aircraft body, wings and a lift augmentation power assembly. The wings comprise an upper wing, a lower wing and a vertical fin, one ends of the upper wing and the lower wing are connected through the vertical fin, the upper wing and the lower wing are equal in chord length, and the ratio of the chord length to the distance between the upper wing and the lower wing is 0.8; the high lift power assembly comprises a folding propeller, a driving motor and a slotted flap. The range extending power system comprises a variable pitch propeller, a fuel engine, a motor, a power conversion unit and a storage battery; the folding propellers are mounted at the front edges of the wings; the fuel engine is connected with the variable-pitch propeller, and the motor is connected with the variable-pitch propeller and the power conversion unit. Compared with the prior art, performance breakthrough is achieved through oil-electricity hybrid power; on the premise of not excessively increasing the extension length of the wings, the lift force is directly increased by increasing the total area of the wings through the double-layer wings, and the infiltration area of the aircraft is reduced by adopting the canard wings to carry out large-attack-angle longitudinal control.

Description

Technical Field

[0001] The present invention relates to an aircraft, in particular to an electric short take-off and landing biplane aircraft. Background Art

[0002] As the global population continues to grow, urban ground transportation is approaching saturation. To meet the demand for faster travel, the concept of UAM (Urban Air Mobility) and eVTOL (Electric Vertical Takeoff and Landing) aircraft have emerged. However, given the more relaxed takeoff and landing conditions, short takeoff and landing (STOL) offers advantages over vertical takeoff and landing, meeting all flight requirements at a lower cost and in a simpler environment.

[0003] Although the reliability of multi-rotor E-VTOL may be higher than that of helicopters, its flight speed is 70 to 120 km / h, which can basically meet current needs, but its payload and range are relatively limited, and the application scenarios it faces are relatively fixed; there are no breakthrough solutions in noise control and ground damage control; the multi-rotor configuration has a smaller rotor load and higher hovering efficiency, but due to the lack of wings, the cruising efficiency is poor, so it is only more advantageous in short-distance scenarios; in terms of safety, due to the large number of power components in multi-rotors, there is a high probability that the rotors will affect each other. During flight, if a rotor has a problem, the other rotors will inevitably be affected; in forward flight, the multi-rotor configuration has a large wind resistance. In order to maintain flight performance and ensure battery safety, its cruising speed is basically around 60 km / h, and the range is relatively small. In comparison, the range and speed problems of traditional multi-rotor aircraft have always been difficult to solve.

[0004] A search revealed application publication number CN103192981A, which discloses an electric, low-noise, short-takeoff and landing (STOL) twin-wing aircraft. Specifically, it includes: a fuselage; a straight trapezoidal front wing located above the fuselage; a forward-swept, upward-angled rear wing located below the fuselage; an endplate connecting the wingtips of the front and rear wings to form a box-shaped structure; a vertical tail; STL performance achieved through slipstream deflection power augmentation; and an electric propeller thrust system and a generator set located within the tail to reduce the overall aircraft noise level. However, a single, non-variable-pitch electric propeller thrust system cannot simultaneously meet the power system's requirements for high thrust output during takeoff and landing, as well as high power output during cruising. The aircraft also lacks a fuel-assisted range-extending power system, limiting its effective range.

[0005] In summary, how to design an aircraft with a short take-off distance, long cruising time and strong flight stability is a technical problem that needs to be solved. Summary of the Invention

[0006] The purpose of the present invention is to provide an electric short take-off and landing biplane aircraft in order to overcome the problems of long take-off distance, short cruising time or poor flight safety in the prior art.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] According to one aspect of the present invention, there is provided an electric short take-off and landing biplane aircraft, comprising an aircraft body, wings, a lift-enhancing power assembly, and a range-extending power assembly;

[0009] There are two wings, symmetrically mounted on both sides of the aircraft body, and the wings include an upper wing, a lower wing, and a vertical tail. One end of the upper wing and the lower wing are respectively mounted on the two sides of the aircraft body away from and close to the ground, and the other ends are connected by the vertical tail. The chord lengths of the upper wing and the lower wing are equal, and the ratio of the chord length to the distance between the upper wing and the lower wing is 0.8;

[0010] The lift-enhancing power assembly includes a folding propeller, a drive motor, and a slotted flap. The folding propeller is mounted on the drive motor. The drive motor is divided into four groups and mounted on the lower surface of the leading edge of the wing. The slotted flap is located on the trailing edge of the wing.

[0011] The extended-range power assembly includes a variable-pitch propeller, a fuel engine, an electric motor, a power conversion unit and a battery; the aircraft body is moving forward, the variable-pitch propeller is installed behind the aircraft body, and the rotation axis of the variable-pitch propeller is parallel to the direction of movement of the aircraft; the fuel engine is connected to the variable-pitch propeller, the electric motor is connected to the variable-pitch propeller and the power conversion unit, and the power conversion unit is connected to the battery.

[0012] As a preferred technical solution, the slotted flaps are installed on the trailing edge of the wing through a flap retraction mechanism.

[0013] As a preferred technical solution, the variable pitch propeller is installed on a transmission shaft and connected to the range-extending power assembly through the transmission shaft.

[0014] As a preferred technical solution, the folding propeller is installed on the leading edge of the wing through a propeller folding mechanism.

[0015] As a preferred technical solution, there are four groups of folding propellers, each group of folding propellers is connected to a power supply module; a group of folding propellers is installed on the upper wing and the lower wing of each of the two wings.

[0016] As a preferred technical solution, the aircraft body includes a connected aircraft head, aircraft fuselage and aircraft tail, and the wings are installed on both sides of the aircraft tail; the interior of the aircraft head is a cockpit, the interior of the aircraft fuselage is a cabin, and the interior of the aircraft tail is equipped with a fuel engine.

[0017] As a preferred technical solution, canards are installed on both sides of the aircraft head.

[0018] As a preferred technical solution, the motor is installed on the wing, and the power conversion unit is installed on the fuselage of the aircraft.

[0019] As a preferred technical solution, the aircraft further includes a landing gear, which includes a front landing gear and a main landing gear. The front landing gear is installed on the aircraft fuselage, and the main landing gear is installed on the lower wing.

[0020] As a preferred technical solution, the aircraft further includes a weather radar, which is connected to a battery.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1) This invention combines the advantages of rotorcraft for small-field takeoff and landing with the efficient cruising characteristics of fixed-wing aircraft: a performance breakthrough is achieved through the hybrid power of the lift-boosting power assembly. It utilizes a mature and reliable dual-module system of electric drive and fuel power, and adopts an intelligent energy management strategy: during takeoff and landing, a high-power density electric motor drives the variable-pitch propeller. During cruising, the fuel engine simultaneously drives the variable-pitch propeller and the electric motor intelligently charges the battery, at which point the motor switches to a generator set. This system retains the instantaneous power response advantage of the electric system while fully utilizing the energy density advantage of fuel, achieving the complementary advantages of the two power sources. This improves endurance compared to pure electric solutions while significantly reducing fuel consumption compared to traditional helicopters.

[0023] 2) The present invention has an overall double-wing, tailless configuration. Without excessively increasing the wing span, the double-wing increases the total wing area to directly increase lift, and the lift coefficient is improved through the vortex interference effect between the double-wing. In terms of overall aircraft maneuverability, the tail is eliminated and canards are used for dynamic control, reducing the aircraft's wetted area.

[0024] 3) This invention utilizes folding propellers on the leading edge of the wings, coupled with two-stage adaptive slotted flaps on the trailing edge. Under standard atmospheric conditions, this design enables a takeoff roll distance of less than or equal to 150 meters (75% shorter than comparable fixed-wing aircraft). Compared to conventional e-VTOL aircraft, this design significantly reduces operational constraints, significantly improving the wind speed adaptability of the takeoff and landing area. At low speeds, the extended-range power unit participates in pitch and yaw control, and the cruise and takeoff and landing power systems are separated, enabling the power system to meet the requirements of different operating conditions, with takeoff and landing requirements no significantly higher than those of e-VTOL.

[0025] 4) The key flight control mechanism of the present invention only includes three sets of control surfaces: flaps, rudders and canards. The power system adopts a distributed four-group independent variable-pitch propeller, and achieves low noise characteristics through a wing-body fusion layout. Each power unit is equipped with an independent power supply line, which can automatically reconstruct the thrust distribution strategy when a single power group fails. It can allow up to two power units to fail at the same time. Environmental adaptability is specially enhanced in response to commercial operation needs: the protection level of the whole aircraft reaches the IP54 standard. During take-off and landing, the aircraft of this scheme has a higher relative flight speed than vertical take-off and landing aircraft, which brings stronger maneuverability and can take off and land stably under level 4 crosswind conditions (5-7m / s). The intelligent avoidance system equipped with a weather radar can cope with complex weather conditions such as sandstorms and freezing rain. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The figure is a schematic diagram of the overall structure of an electric short take-off and landing biplane aircraft of the present invention.

[0027] Figure 2 This is a top view of an electric short take-off and landing biplane aircraft of the present invention.

[0028] Figure 3 It is a schematic diagram of the slotted flap structure of the present invention.

[0029] Figure 4 This is a schematic diagram of the installation of the variable pitch propeller and the propeller folding mechanism of the present invention.

[0030] The numbers in the figure show:

[0031] 1. Aircraft head, 2. Aircraft fuselage, 3. Aircraft tail, 4. Upper wing, 5. Lower wing, 6. Slotted flaps, 7. Vertical tail, 8. Canard, 9. High-lift propeller assembly, 10. Propeller folding mechanism, 11. Folding propeller, 12. Fuel engine, 13. Motor, 14. Power conversion unit, 15. Battery, 16. Landing gear, 17. Variable-pitch propeller. DETAILED DESCRIPTION

[0032] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0033] The present invention provides an electric short take-off and landing biplane aircraft, comprising an aircraft body, wings, canards 8, a lift-increasing power assembly 9, a range-extending power assembly, a landing gear 16, and a weather radar.

[0034] The aircraft body consists of a nose 1, fuselage 2, and tail 3, which are connected in sequence. The nose 1 houses the cockpit, while the fuselage 2, which primarily supports the other two parts, houses the cabin. The tail 3 houses a fuel engine 12. Two canards 8 are symmetrically mounted on either side of the nose 1. During level flight, the canards 8 deflect positively, generating positive lift, which is balanced by the nose-up moment, increasing the overall lift of the aircraft. Two wings are symmetrically mounted on either side of the tail 3, with motors 13 mounted on the wings. A power conversion unit 14 is mounted on the fuselage 2. The canards 8 deflect perpendicularly to the aircraft's flight direction, acting as elevators. The aircraft body also includes a rudder.

[0035] The wings include an upper wing 4, a lower wing 5, and a vertical tail 7. One end of the upper wing 4 and lower wing 5 is mounted on either side of the aircraft, away from and close to the ground, respectively, and the other end is connected by the vertical tail 7. The chord lengths of the upper and lower wings 4, 5 are equal, and the ratio of the chord length to the distance between the upper and lower wings 4, 5 is 0.8. The distance between the projections of the upper and lower wings 4, 5 on the horizontal plane is half the chord length. This structure effectively reduces the drag generated by the connection between the wings and the fuselage. The upper and lower wings 4, 5 are made of the same material. The vertical tail 7 provides the aircraft with lateral static stability and provides lateral damping torque, that is, lateral dynamic stability.

[0036] The lift-enhancing power assembly 9 includes a foldable propeller 11, a drive motor, and a slotted flap 6. The aircraft body is moving forward. The foldable propeller 11 is mounted on the leading edge of the wing through a propeller folding mechanism 10. The propeller folding mechanism 10 is used to retract the foldable propeller 11 during cruising. The blades can be folded backwards and the frontal area can be reduced after stopping. Figure 4 As shown, resistance is reduced; there are four groups of folding propellers 11, each group of folding propellers 11 is connected to a power supply module; a group of folding propellers 11 is installed on each of the upper wing 4 and the lower wing 5 of the two wings, and a group of folding propellers 11 installed on each upper wing 4 is three, and a group of folding propellers 11 installed on each lower wing 5 is five.

[0037] The wing trailing edge is equipped with slotted flaps 6 through a flap retraction mechanism; the flaps are opened to a certain angle during takeoff to provide additional lift for the aircraft at low speeds. The folding propeller 11 is activated during takeoff and landing to blow air to the slotted flaps 6 to provide additional lift for the aircraft at low speeds. Figure 3 As shown, the slotted flap 6 with three slots can greatly increase the aircraft's lift coefficient, allowing the aircraft to fly at a slower speed. Based on the slotted flap 6, an active blowing device is added to the lower surface, namely the folding propeller 11 in this solution, which further improves the efficiency of the slotted flap 6, increases the aircraft's lift coefficient, and reduces flight speed.

[0038] The range-extending power assembly includes a variable-pitch propeller 17, a fuel engine 12, an electric motor 13, a power conversion unit 14 and a battery 15; the variable-pitch propeller 17 is installed at the rear of the fuselage, and the rotation axis of the variable-pitch propeller 17 is parallel to the forward direction of the aircraft.

[0039] The fuel engine 12 is connected to a variable-pitch propeller 17, and the motor 13 is connected to the variable-pitch propeller 17 and the power conversion unit 14. The power conversion unit 14, the flap retraction mechanism, and the propeller folding mechanism 10 are connected to a battery 15. During takeoff and landing, the battery 15 primarily drives the motor and propeller through the power conversion unit 14 to provide power for the aircraft, thereby reducing noise. During cruising, the fuel engine 12 drives the propeller to provide power, and the electric motor generates reverse electricity, which is charged by the power conversion unit 14 to charge the battery 15.

[0040] During flight, the variable-pitch propeller 17 automatically changes its blade angle based on the aircraft's speed and altitude. During takeoff, the propeller's blade angle is reduced to maximize propeller thrust. During level flight, the pitch is shifted to high pitch, allowing the variable-pitch propeller 17 to draw maximum useful power from the engine at maximum speed. After the aircraft touches down, the pitch is shifted to negative, creating a braking effect and reducing landing distance. Therefore, the variable-pitch propeller 17 utilizes the engine's maximum useful power at any flight speed.

[0041] The present invention has more ample space, and the battery 15 can be safely fixed to the lower part of the center of gravity of the fuselage through a special disconnectable mechanical device. When an unexpected situation occurs with the battery, the fixing device can be disconnected and the battery can be discarded.

[0042] The landing gear 16 is an accessory device used to support the aircraft during takeoff, landing or ground taxiing and is used for ground movement; it includes a front landing gear 16 and a main landing gear 16, the front landing gear 16 is installed on the aircraft fuselage 2, and the main landing gear 16 is installed on the lower wing 5.

[0043] The weather radar is connected to the battery 15.

[0044] The present invention works as follows:

[0045] During takeoff, the slotted flaps 6 located at the trailing edges of the upper and lower wings 5 of the aircraft are opened to their maximum angle. The flap retraction mechanism unfolds the blades of the folding propellers 11 of the 16 lift-enhancing power modules 9 at the leading edges of the wings, so that the blades face the direction of the aircraft's takeoff and are activated at rated power, providing thrust for the aircraft and cooperating with the slotted flaps 6 to generate additional lift. At the same time, the variable-pitch propellers 17 are pitched to the takeoff pitch, and the electric motor located at the tail of the aircraft is activated, driving the variable-pitch propellers 17 to provide forward power for the aircraft's takeoff. During the 50-100m takeoff glide, the front canards 8 are used to gradually lift the aircraft to a takeoff pitch angle of 20 degrees and reach the minimum takeoff speed. After leaving the ground, the aircraft gradually accelerates and the slotted flaps 6 are gradually retracted according to the speed. The folding propellers 11 of the lift-enhancing power modules 9 are closed after reaching the cruising altitude to reduce resistance during level flight. At this time, the variable-pitch propellers 17 are driven by the fuel engine 12 to provide thrust.

[0046] During the landing process of the aircraft, the slotted flaps 6 are opened to the maximum angle, and the propeller folding mechanism 10 causes the variable pitch propeller 17 to open in the opposite direction. After the lift-enhancing power assembly 9 is started, it provides the aircraft with backward thrust and cooperates with the flaps to generate additional lift to reduce the flight speed during landing. At the same time, the front canard 8 is used to increase the aircraft's pitch angle to 20°, and the aircraft's level flight speed is controlled at around 20m / s. After the aircraft touches the ground, the variable pitch propeller 17 switches the pitch to the reverse propeller to generate reverse thrust for braking. The fuel engine 12 mainly provides power for the aircraft's main propeller, that is, the variable pitch propeller 17, during the cruising phase; the motor 13 mainly provides additional power to the aircraft during the take-off and landing phases, and is converted into a generator 13 to charge the battery 15 during the cruising process.

[0047] The fuel engine and battery pack of the present invention work together to output power, dynamically adjusting the power ratio through real-time mission profile analysis (takeoff, cruise, landing), and flexibly leveraging the advantages of different power sources.

[0048] The present invention combines the advantages of vertical take-off and landing of rotary-wing aircraft with the high-efficiency cruising characteristics of fixed-wing aircraft: a performance breakthrough is achieved through a hybrid oil-electric system. The system integrates mature and reliable electric drive and fuel power dual modules, and adopts an intelligent energy management strategy: during the take-off and landing phases, the high-power density motor 13 drives the propeller system to work, and a specially designed high-rate lithium polymer battery pack provides instantaneous high-power output; after switching to level flight cruise mode, the fuel engine 12 synchronously drives the propeller and intelligently charges the battery pack. At this time, the motor 13 is converted into a generator 13 group. This architecture retains the instantaneous power response advantage of the electric system and fully utilizes the energy density advantage of fuel. The dynamic energy distribution algorithm realizes the complementary advantages of the two power sources, which improves the endurance compared to the pure electric solution and reduces a lot of fuel consumption compared to traditional helicopters.

[0049] This invention features a simple structure and a short design verification cycle: It employs a revolutionary simplified design. Its core aerodynamic layout inherits the proven genes of traditional fixed-wing aircraft and undergoes topological optimization: a semi-monocoque aluminum alloy fuselage with minimal moving parts, and critical flight control mechanisms comprise only three control surfaces: flaps, rudder, and elevators. The power system utilizes four distributed independent fans, achieving low noise through a wing-body fusion layout. Each power unit is equipped with an independent power supply circuit, automatically reconfiguring the thrust distribution strategy in the event of a single power unit failure, allowing for the simultaneous failure of up to two power units. Environmental adaptability is specifically enhanced to meet the needs of commercial operations: during takeoff and landing, the aircraft boasts a higher relative speed than vertical takeoff and landing (VTOL) aircraft, resulting in greater maneuverability and resistance to strong winds. The aircraft meets IP54 protection standards and can take off and land stably in level 4 crosswinds (5-7 m / s). The intelligent avoidance system, equipped with a weather radar, can handle complex weather conditions such as sandstorms and freezing rain.

[0050] Wing-body fusion is a revolutionary aircraft design concept that breaks through the traditional aircraft configuration of "cylindrical fuselage + independent wings + tail fins" and seamlessly integrates the fuselage and wings into a continuous, smooth lifting body. This design is not just a "smooth transition" in appearance. Under the traditional layout, the fuselage is cylindrical or conical, and the wings are independent. The two are transitioned through a fairing, and there is a noticeable seam. Wing-body fusion can eliminate the boundary between the fuselage and the wing. The entire aircraft is like a flat flying wing. The central wide part is both the cabin and the lifting surface; the outer wing part continues to generate lift without abrupt transitions. The entire aircraft surface works together to generate lift, reducing the invalid volume load and transferring it along the smooth curved surface, reducing stress concentration. In addition, this design can eliminate airflow separation at the fuselage-wing connection and reduce interference drag.

[0051] This invention boasts a short takeoff distance and low takeoff requirements: It utilizes a revolutionary powered lift assembly to achieve ultra-short takeoff and landing performance. Its core technology is a blown flap system based on a CCW circulation-controlled wing. Propellers are positioned on the leading edge of the wing, coupled with two-stage adaptive blown flaps (with adjustable slot angles) on the trailing edge. Based on empirical calculation equations provided in the aircraft design manual, this invention achieves a takeoff run distance of less than or equal to 150 meters under standard atmospheric conditions (75% shorter than comparable fixed-wing aircraft). Compared to conventional e-VTOL aircraft, this design significantly reduces operational constraints, significantly improving the wind speed adaptability of the takeoff and landing field. At low speeds, the system participates in pitch and yaw control, and the cruise and takeoff and landing power systems are separate, meeting the power system requirements of different operating conditions. The takeoff and landing requirements are no more significantly higher than those of e-VTOL aircraft.

[0052] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. An electric short take-off and landing biplane aircraft, characterized in that: It includes an aircraft body, wings, a lift-increasing power assembly (9) and a range-increasing power assembly; There are two wings, which are symmetrically mounted on both sides of the aircraft body. The wings include an upper wing (4), a lower wing (5) and a vertical tail (7). One end of the upper wing (4) and the lower wing (5) are respectively mounted on the two sides of the aircraft body away from and close to the ground, and the other ends are connected through the vertical tail (7). The chord lengths of the upper wing (4) and the lower wing (5) are equal, and the ratio of the chord length to the distance between the upper wing (4) and the lower wing (5) is 0.8; The lift-enhancing power assembly (9) comprises a folding propeller (11), a drive motor and a slotted flap (6), wherein the folding propeller (11) is mounted on the drive motor, the drive motor is divided into four groups and mounted on the lower surface of the leading edge of the wing, and the slotted flap (6) is located at the trailing edge of the wing; The range-extending power assembly comprises a variable-pitch propeller (17), a fuel engine (12), a motor (13), a power conversion unit (14) and a storage battery (15); the aircraft body is moving forward, the variable-pitch propeller (17) is installed behind the aircraft body, and the rotation axis of the variable-pitch propeller (17) is parallel to the moving direction of the aircraft; the fuel engine (12) is connected to the variable-pitch propeller (17), the motor (13) is connected to the variable-pitch propeller (17) and the power conversion unit (14), and the power conversion unit (14) is connected to the storage battery (15).

2. The electric short take-off and landing biplane aircraft according to claim 1, characterized in that: The wing trailing edge is provided with a slotted flap (6) via a flap retracting and extending mechanism.

3. The electric short take-off and landing biplane aircraft according to claim 2, characterized in that: The variable pitch propeller (17) is mounted on a transmission shaft and is connected to a range-extending power assembly via the transmission shaft.

4. The electric short take-off and landing biplane aircraft according to claim 1, characterized in that: The folding propeller (11) is installed on the leading edge of the wing through a propeller folding mechanism (10).

5. The electric short take-off and landing biplane aircraft according to claim 1, characterized in that: There are four groups of folding propellers (11), and each group of folding propellers (11) is connected to a power supply module; one group of folding propellers (11) is respectively installed on the upper wing (4) and the lower wing (5) of the two wings.

6. The electric short take-off and landing biplane aircraft according to claim 1, characterized in that: The aircraft body comprises a connected aircraft head (1), an aircraft fuselage (2) and an aircraft tail (3), wherein the wings are mounted on both sides of the aircraft tail (3); the interior of the aircraft head (1) is a cockpit, the interior of the aircraft fuselage (2) is a cabin, and the interior of the aircraft tail (3) is a fuel engine (12).

7. The electric short take-off and landing biplane aircraft according to claim 6, characterized in that: Canards (8) are installed on both sides of the aircraft head (1).

8. The electric short take-off and landing biplane aircraft according to claim 6, characterized in that: The motor (13) is mounted on the wing, and the power conversion unit (14) is mounted on the aircraft fuselage (2).

9. The electric short take-off and landing biplane aircraft according to claim 6, characterized in that: The aircraft also includes a landing gear (16), which includes a front landing gear (16) and a main landing gear (16). The front landing gear (16) is installed on the aircraft fuselage (2), and the main landing gear (16) is installed on the lower wing (5).

10. The electric short take-off and landing biplane aircraft according to claim 1, characterized in that: The aircraft also includes a weather radar connected to a battery (15).

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