Propeller blowing wing lift augmentation type tilting composite wing aircraft

Abstract

The utility model belongs to the technical field of aircrafts, and particularly discloses a propeller blowing wing lift augmentation type tilting composite wing aircraft which comprises an aircraft body, wings symmetrically distributed on the two sides of the aircraft body, a control system and a power device, and the power device comprises a plurality of vertical propellers and a plurality of forward pulling propellers. The vertical propellers are symmetrically arranged on the fuselage and / or the wings with the center of gravity of the aircraft as the center, the front pulling propellers are installed in front of the wings, the propeller disc center lines of the front pulling propellers and the wing chords of the wings form an attack angle of an included angle alpha, and the control system is used for controlling the control quantities of all control planes of the aircraft and the rotating speeds and the rotating directions of the propellers. The control method comprises the following steps: controlling a vertical take-off mode, a vertical landing mode and a hovering mode, adjusting the rotating speed of each propeller to enable the fuselage to backwards tilt for theta to raise the head, so that the force borne by the aircraft in all directions is balanced to realize hovering, and the resultant force vertically moves upwards or downwards to realize vertical take-off or landing. The aircraft is compact in structure, smooth in vertical rotation, safe and reliable.

Description

Technical Field

[0001] The utility model belongs to the technical field of aircraft, and particularly relates to a propeller blowing wing lift-increasing tilt compound wing aircraft. Background Technique

[0002] Common vertical takeoff and landing fixed-wing aircraft are divided into three categories: compound wing, tilt type and tail-sitter type.

[0003] Among them, most of the compound wing vertical takeoff and landing fixed-wing aircraft directly install multi-rotors or lift propellers on the basis of the fixed wing. During the vertical takeoff and landing stage, the multi-rotor or propeller system provides lift, and during the level flight stage, it switches back to the fixed wing mode. Although the technology maturity is relatively high, during vertical takeoff and landing or cruise level flight, one of its vertical and horizontal lift / thrust devices needs to stop working and completely becomes useless weight, resulting in a low mass efficiency of the whole aircraft. At the same time, during the transition stage, the vertical takeoff and landing power still exists, so the power wake will generate aerodynamic interference on components such as the wing and horizontal tail, affecting the operation and control.

[0004] The tilt type vertical takeoff and landing fixed-wing aircraft refers to that the UAV tilts the power component upward or forward as required during vertical takeoff and landing and level flight. However, since the tilt rotor needs to be used as a helicopter rotor during vertical takeoff and landing and as a fixed wing pull / propulsion propeller during level flight, and the working environments of the vertical takeoff and landing and cruise modes are significantly different, it brings many problems for the rotor system to balance the comprehensive efficiency of multi-modal vertical takeoff and landing, transition and forward flight, and faces serious rotor / wing aerodynamic interference problems, with poor controllability and low safety.

[0005] The tail-sitter type vertical takeoff and landing fixed-wing aircraft adopts a modal conversion method of rotating the whole UAV by 90°. The vertical takeoff and landing scheme does not require an additional motion deflection mechanism, but its center of gravity is relatively high during vertical takeoff and landing, and it is easily affected by side winds and terrain, with a risk of capsizing and poor safety.

[0006] To sum up, the three design methods of the vertical takeoff and landing fixed-wing aircraft in the prior art have their own advantages and disadvantages. During the vertical takeoff and landing state, level flight mode or transition state between the two of the aircraft, there are certain problems with the power device, resulting in air flow interference on the aircraft, and an aircraft that can balance simple structure and low air flow interference degree is needed. Content of the Utility Model

[0007] Aiming at the deficiencies in the prior art, the utility model provides a propeller blowing wing lift-increasing tilt compound wing aircraft to solve the problems of low vertical takeoff and landing efficiency of the aircraft and easy interference and separation of the air flow on the wing when the vertical takeoff and landing attitude changes to the level flight attitude.

[0008] According to an embodiment of the present utility model, the following technical solution is adopted: a propeller blowing wing lift-increasing tilting compound wing aircraft, including a fuselage, wings symmetrically distributed on both sides of the fuselage, a control system, and a power device. The power device includes a plurality of vertical lift propellers and a plurality of forward pull propellers. Each vertical lift propeller is symmetrically arranged on the fuselage and / or the wings with the aircraft's center of gravity as the center. Each forward pull propeller is installed in front of the wings, and the center line of the propeller disc of the forward pull propeller forms an angle of α with the chord of the wing. The control system is used to control the rudder surface deflections, the rotational speed, and the rotation direction of the propellers of the aircraft.

[0009] In the present utility model, the high-speed airflow blown out by the forward pull propeller disc flows towards the wing at an angle of attack α, generating an aerodynamic coupling effect with the wing, and producing a forward and upward pulling force on the aircraft. When the aircraft needs to take off and land vertically or hover, the control system controls the vertical lift propellers and the forward pull propellers to work simultaneously. By controlling the rotational speed difference of each propeller, the fuselage is tilted backward by an angle of θ, making the forces acting on the aircraft in all directions balanced to achieve hovering. When the resultant force acting on the aircraft is upward, vertical takeoff is achieved, and when the resultant force acting on the aircraft is downward, vertical landing is achieved.

[0010] Compared with the prior art, the present utility model has the following beneficial effects:

[0011] In this solution, when the aircraft is taking off and landing vertically or hovering, through the mutual cooperation of the vertical lift propellers and the forward pull propellers working simultaneously, after the fuselage tilts backward by an angle of θ, the forward pull propeller generates an upward component force. At the same time, when the high-speed airflow blown out by the forward pull propeller disc flows through the wing and the flaps and ailerons under the wing, a large aerodynamic coupling lift-increasing effect is generated, thereby significantly reducing the power configuration of the vertical lift propellers. Compared with the traditional compound wing vertical takeoff and landing fixed-wing aircraft, this solution can reduce the power configuration of the vertical lift propellers by more than half. In addition, compared with the traditional tilting wing vertical takeoff and landing fixed-wing aircraft, it does not require a complex power tilting structure. The aircraft of this solution has a compact and simple structure, and has the advantages of large power load, high reliability, light weight, and high speed.

[0012] In addition, in this solution, no matter what flight mode the aircraft is in (vertical takeoff and landing state, level flight mode, or the transition state between the two), there is always the high-speed airflow of the forward pull propeller device blowing towards the wing, so that the aircraft has less airflow interference and separation during the transition state, can transition more smoothly, and has better wind resistance, and can fly safely and reliably in complex terrains such as ultra-low altitude and canyons and complex airflow environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic structural diagram of the ordinary propeller blowing wing lift-increasing tilting compound wing aircraft according to the embodiment of the present utility model, and the arrow indicates the airflow direction during level flight.

[0014] Figure 2This is a schematic structural diagram of a ducted propeller blown-wing lift-increasing tilting compound-wing aircraft according to an embodiment of the present invention, and the arrow indicates the airflow direction during level flight.

[0015] Figure 3 This is a schematic structural diagram of the ducted propeller installed on the wing in an embodiment of the present invention, and the arrow indicates the airflow direction during level flight.

[0016] Figure 4 This is a schematic structural diagram of the wing flap lowering and the cooperation with the ducted propeller during vertical takeoff and landing or hovering in an embodiment of the present invention, and the arrow indicates the airflow direction during vertical takeoff and landing or hovering.

[0017] Figure 5 This is a schematic diagram of the fuselage tilting backward by an angle θ during vertical takeoff and landing or hovering of a propeller blown-wing lift-increasing tilting compound-wing aircraft according to an embodiment of the present invention, and the arrow indicates the airflow direction during vertical takeoff and landing or hovering.

[0018] Figure 6 This is a schematic diagram of the force analysis during hovering in an embodiment of the present invention.

[0019] Figure 7 This is a schematic diagram of the force analysis during vertical takeoff in an embodiment of the present invention.

[0020] Figure 8 This is a schematic diagram of the force analysis during vertical landing in an embodiment of the present invention.

[0021] Figure 9 This is a schematic diagram of the force analysis during level flight in an embodiment of the present invention.

[0022] In the figure: 1, fuselage; 2, wing; 3, flap; 4, aileron; 5, tail wing; 6, vertical takeoff and landing ordinary propeller; 7, landing gear; 8, control system; 9, forward pull ordinary propeller; 10, vertical takeoff and landing ducted propeller; 11, forward pull ducted propeller; 12, duct; 13, chord line; 14, center line of propeller disk; 15, leading edge of wing; 16, propeller disk. Specific embodiments

[0023] The following further elaborates on the present invention in detail with reference to the accompanying drawings of the specification and provides specific embodiments.

[0024] In a first aspect, the present invention discloses a propeller blown-wing lift-increasing tilting compound-wing aircraft, which specifically includes the following embodiments:

[0025] As Figure 1 、 Figure 2As shown, the propeller-blown wing lift-increasing tilt-rotor compound wing aircraft includes a fuselage 1, wings 2 symmetrically distributed on both sides of the fuselage 1, a control system 8, and a power plant. Of course, like a conventional aircraft, it also includes a tail wing 5, a landing gear 7 and other structures. These structures are not improved in this embodiment and will not be elaborated here. The wing 2 can be any one of a single wing or a tandem bi-wing in the prior art. When the wing 2 is a tandem bi-wing, the tail wing 5 can be removed. As Figure 1 shown, the wing 2 is designed as a single wing and can be selected according to the actual design situation.

[0026] The power plant includes a plurality of vertical lift propellers and a plurality of forward pull propellers. Each vertical lift propeller is symmetrically arranged on the fuselage 1 and / or the wing 2 with the center of gravity of the aircraft as the center. Each forward pull propeller is installed in front of the wing 2. The center line 14 of the propeller disk of the forward pull propeller forms an angle of attack α with the chord line 13 of the wing 2, and the angle of the angle of attack α is 0° to 20°. The control system 8 is used to control the rudder surface deflection, the propeller speed and the steering of the aircraft.

[0027] As the angle of attack α increases, the aerodynamic coupling effect between the high-speed airflow generated by the propeller and the wing gradually increases, and the additional lift generated on the wing gradually increases. When the angle of attack α increases to 15° to 20°, the aerodynamic coupling effect between the high-speed airflow generated by the propeller and the wing reaches the strongest, and the additional lift generated on the wing reaches the extreme value; if the angle of attack α is further increased, airflow separation may occur.

[0028] The forward pull propeller is arranged on the wing 2 and is located in front of and below the wing 2, and is used to blow high-speed airflow towards the wing 2. The high-speed airflow blown by the forward pull propeller flows towards the wing 2 at the angle of attack α, generates an aerodynamic coupling effect with the wing 2, and generates a forward and upward pulling force on the aircraft.

[0029] The vertical lift propeller provides an upward pulling force perpendicular to the fuselage 1 for the aircraft. The vertical lift propeller is a vertical ordinary propeller 6 or a vertical ducted propeller 10. The vertical ordinary propeller 6 is composed of a propeller disk 16 and a motor, and the vertical ducted propeller 10 refers to the vertical ordinary propeller 6 wrapped by a duct 12.

[0030] The forward pull propeller provides a forward pulling force for the aircraft. The forward pull propeller is a forward pull ordinary propeller 9 or a forward pull ducted propeller 11. The forward pull ordinary propeller 9 is composed of a propeller disk 16 and a motor, and the forward pull ducted propeller 11 refers to the forward pull ordinary propeller 9 wrapped by a duct 12. The forward pull propeller is installed in front of and below the leading edge 15 of the wing. The high-speed airflow blown by the forward pull propeller flows towards the wing 2 at the angle of attack α, generates an aerodynamic coupling effect with the wing 2 and the flaps 3 and ailerons 4 below the wing 2 to produce a blowing power lift-increasing effect, and also generates a resistance effect due to blocking the airflow, generating an upward lift and a backward resistance on the wing 2.

[0031] The tractor propeller is fixedly connected, rotationally connected or hinged to the wing 2, whichever is applicable. When the tractor propeller is rotationally connected or hinged to the wing 2, the angle α between the propeller disc center line 14 of the tractor propeller and the wing chord 13 of the wing 2 can be adjusted according to the control system 8, as shown in Figure 3 the state shown.

[0032] The wing 2 includes a wing body and a flap 3 and a aileron 4 movably connected to the wing body. Among them, the flap 3 includes any one or a combination of a leading-edge flap, a leading-edge slat, and a trailing-edge flap. By adjusting the lowering angle of the flap 3 through the control system 8, the magnitude and direction of the lift and drag forces received by the wing 2 can be adjusted, as shown in Figure 3 , Figure 4 the different lowering angles of the flap 3 shown.

[0033] In addition, the propeller blowing wing lift-increasing tilt-rotor compound wing aircraft can be controlled in the following manner: including the control of a vertical takeoff mode, a vertical landing mode, and a hovering mode, and the control method is as follows: In the vertical takeoff mode, the vertical landing mode, or the hovering mode, both the vertical lift propeller and the tractor propeller need to be in a working state at the same time; the angle between the propeller disc center line of the tractor propeller and the wing chord a is adjusted to a larger value to increase the lift; the rotational speed of the vertical lift propeller in front of the center of gravity position of the fuselage 1 is controlled to be greater than the rotational speed of the vertical lift propeller behind the center of gravity position of the fuselage 1 through the control system 8, and the fuselage 1 is in a posture of tilting backward with the head up, forming a tilt angle θ, as shown in Figure 5 the state shown; the tilt angle θ is less than 45°, and the tilt angle θ is generally controlled within 10° to 30°.

[0034] The tilt angle θ is determined by conditions such as the ratio of the tractor power to the vertical lift power, the takeoff weight, and the wind speed. The smaller the proportion of the tractor power, the lighter the takeoff weight, and the greater the wind speed, the smaller the tilt angle θ, and vice versa. However, considering the riding comfort, the tilt angle θ should not be too large. Therefore, the tilt angle θ is controlled to be less than 45°, and is generally controlled within 10° to 30°.

[0035] As Figure 6 shown, during the hovering mode control: keep the horizontal components of the tractor propeller pull F 1 , the wing lift F 3 , and the vertical lift propeller pull F 2 in a balanced state, and the sum of the vertical components of the tractor propeller pull F 1 , the wing lift F 3 , and the vertical lift propeller pull F 2 is balanced with the gravity G of the aircraft, that is, the control algorithm equation of formula (1) is satisfied:

[0036] Formula (1):

[0037] F1 cosθ ≈ F 2 sinθ + F 3 sinθ

[0038] F 1 sinθ + F 2 cosθ + F 3 cosθ ≈ G

[0039] As Figure 7 shown, during vertical takeoff mode control: increase the rotational speeds of the forward pull propeller and the vertical takeoff propeller, and keep the thrust F of the forward pull propeller 1 , the wing lift F 3 , the thrust F of the vertical takeoff propeller 2 in the horizontal direction in a balanced state, and keep the thrust F of the forward pull propeller 1 , the wing lift F 3 , the thrust F of the vertical takeoff propeller 2 in the vertical direction, the sum of the components is greater than the gravity G of the aircraft, making the resultant force on the aircraft vertically upward, that is, satisfying the control algorithm equation of formula (2):

[0040] Formula (2):

[0041] F 1 cosθ ≈ F 2 sinθ + F 3 sinθ

[0042] F 1 sinθ + F 2 cosθ + F 3 cosθ > G

[0043] As Figure 8 shown, during vertical landing mode control: by reducing the rotational speeds of the forward pull propeller and the vertical takeoff propeller, keep the thrust F of the forward pull propeller 1 , the wing lift F 3 , the thrust F of the vertical takeoff propeller 2 in the horizontal direction in a balanced state, and keep the thrust F of the forward pull propeller 1 , the wing lift F 3 , the thrust F of the vertical takeoff propeller 2 in the vertical direction, the sum of the components is less than the gravity G of the aircraft, making the resultant force on the aircraft vertically downward, that is, satisfying the control algorithm equation of formula (3):

[0044] Formula (3):

[0045] F 1 cosθ ≈ F 2 sinθ + F 3 sinθ

[0046] F1 sinθ + F 2 cosθ + F 3 cosθ < G.

[0047] The control method of the propeller blowing wing lift-increasing tilting compound wing aircraft also includes the control of the level flight transition mode, and the control method of the level flight transition mode is as follows:

[0048] Control each vertical propeller to gradually reach the same rotational speed state, so that the fuselage 1 is gradually adjusted to a horizontal attitude;

[0049] As Figure 9 shown, adjust the rotational speeds of the vertical propeller and the forward pulling propeller, and keep the wing lift F., the sum of the vertical propeller thrust F 2 balanced with the gravity of the aircraft, and keep the forward pulling propeller thrust F 1 greater than zero, so that the aircraft accelerates forward. As the speed of the aircraft increases, gradually reduce the rotational speed of the vertical propeller and retract the flap 3, so that the resultant force received by the aircraft is forward, that is, satisfy the control algorithm equation of formula (4):

[0050] Formula (4):

[0051] F1 > 0

[0052] F 2 + F 3 ≈ G

[0053] After the aircraft accelerates to the conversion speed, turn off the vertical propeller. At the same time, the angle a between the center line of the forward pulling propeller disk and the wing chord can be adjusted to a smaller value to reduce the resistance, and the aircraft transitions to the level flight mode, satisfying the algorithm equation of formula (5):

[0054] Formula (5):

[0055] F 1 > 0

[0056] F 3 ≈ G

[0057] At this time, increase the throttle, increase the rotational speed of the forward pulling propeller, and increase the forward pulling propeller thrust F,, and the aircraft flies at high speed; reduce the throttle, reduce the rotational speed of the forward pulling propeller, and reduce the forward pulling propeller thrust F,, and the aircraft flies at low speed.

[0058] When the aircraft needs to hover, the control system 8 controls the vertical lift propellers and the forward pull propellers to work simultaneously. The vertical lift propellers generate an upward pulling force, and the forward pull propellers generate a forward pulling force. When the high-speed airflow blown out by the forward pull propeller disk flows through the wing 2 and the flaps 3 and ailerons 4 below the wing 2, it produces an aerodynamic coupling lift increase and drag effect. The control system 8 adjusts the rotational speed of the vertical lift propellers at the front of the fuselage 1 to be higher than that of the vertical lift propellers at the rear of the fuselage 1, causing the fuselage 1 to lift its head and tilt backward by an angle θ. At the same time, by adjusting the rotational speeds of other propellers through the control system 8, the horizontal component forces of the forward pull propeller pulling force, the wing 2 lift force, and the vertical lift propeller pulling force are mutually offset and balanced, and the sum of the vertical component forces of the forward pull propeller pulling force, the wing 2 lift force, and the vertical lift propeller pulling force is balanced with the gravity, making the forces acting on the aircraft in all directions balanced, and thus enabling the aircraft to achieve hovering; the angle θ at which the fuselage 1 lifts its head and tilts backward is less than 45°, and is generally controlled between 10° and 30°.

[0059] Increase the throttle to increase the rotational speed of the forward pull propellers and increase the forward pull propeller pulling force F 1 , the aircraft flies at high speed; reduce the throttle to reduce the rotational speed of the forward pull propellers and reduce the forward pull propeller pulling force F 1 , the aircraft flies at low speed.

[0060] When the aircraft needs to transition to the level flight mode, gradually control the rotational speeds of the vertical lift propellers at the front and rear of the fuselage 1 to be the same, causing the fuselage 1 to gradually return to the horizontal attitude. Adjust the rotational speeds of other propellers through the control system 8 so that the resultant force acting on the aircraft is forward. At the same time, gradually retract the flaps 3 and pull the aircraft to accelerate forward. After accelerating to the conversion speed, turn off the vertical lift propellers, and the aircraft enters the level flight mode.

[0061] The control methods of the aircraft can also include the pitch, front-back translation, left-right translation, roll, and rotational maneuver control of the aircraft. Adjusting the rotational speed difference between the front and rear vertical lift propellers enables the aircraft to achieve pitch maneuvers and front-back translation maneuvers; adjusting the deflection angle difference between the left and right ailerons enables left-right translation maneuvers; adjusting the rotational speed difference between the left and right forward pull propellers enables the aircraft to achieve roll and rotational maneuvers.

[0062] For example, in the fixed-wing flight mode, the control system 8 can be used to adjust the aileron 4 control surface and the tail wing 5 control surface to enable the aircraft to achieve pitch, roll, and yaw maneuvers; in the vertical takeoff and landing or hovering flight mode, by adjusting the lowering angles of the flaps 3 and ailerons 4 on the wing 2 through the control system 8, and adjusting the rotational speed difference between the vertical lift propellers at the front and rear of the aircraft's center of gravity, the aircraft can achieve pitch, and adjusting the rotational speed difference between the forward pull propellers on the left and right sides of the fuselage 1 enables the aircraft to achieve roll and rotational maneuvers.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A propeller-blown-wing lift-enhancing tilt-rotating composite-wing aircraft, comprising a fuselage, wings symmetrically distributed on both sides of the fuselage, a control system and a power device, characterized in that: The power unit includes multiple vertical propellers and multiple forward-pull propellers. Each vertical propeller is symmetrically arranged on the fuselage and / or the wing with the center of gravity of the aircraft as the center. Each forward-pull propeller is installed in front of the wing. The centerline of the propeller disk of the forward-pull propeller forms an angle of attack α with the chord of the wing. The control system is used to control the rudder amount of each control surface of the aircraft, the propeller speed and steering.

2. The propeller-blown-wing lift-enhancing tilt-rotating composite-wing aircraft according to claim 1, characterized in that: The angle α is in the range of 0° to 20°.

3. The propeller-blown-wing lift-enhancing tilt-rotating composite-wing aircraft according to claim 1, characterized in that: The vertical propeller is a vertical ordinary propeller or a vertical ducted propeller.

4. The propeller-blown-wing lift-enhancing tilt-rotating composite-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.

5. The propeller-blown-wing lift-enhancing tilt-rotating composite-wing aircraft according to claim 1, characterized in that: The forward-pull propeller is installed at the front lower part of the wing leading edge.

6. The propeller-blown-wing lift-enhancing tilt-rotating composite-wing aircraft according to claim 5, characterized in that: The front-pull propeller and the wing are fixedly connected, rotatably connected or hingedly connected.

7. The propeller-blown-wing lift-enhancing tilt-rotating composite-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.

8. The propeller-blown-wing lift-enhancing tilt-rotating composite-wing aircraft according to claim 7, characterized in that: The flaps include any one or a combination of leading edge flaps, leading edge slats, and trailing edge flaps.

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