A single-ducted aircraft

Abstract

The present invention discloses a single-ducted aircraft, which includes an annular duct, a propeller and four sets of rudder blade mechanisms. The axis of the duct is arranged vertically. The propeller is driven by a driving motor and is arranged in the air duct at the upper part of the duct. The rudder blade mechanisms are arranged at the lower part of the duct and include rudder blades driven by a servo motor. The rudder blades include an airfoil-shaped plate body and a synthetic jet actuator. The plate body includes an inner cavity and a synthetic jet outlet communicating with the inner cavity. The synthetic jet actuator is installed in the inner cavity of the plate body, and the synthetic jet outlet is close to the trailing edge of the airfoil-shaped plate body. The jet outlet of the synthetic jet actuator communicates with the synthetic jet outlet of the plate body. The air duct at the lower part of the duct includes a plurality of guide vanes, which are fixed on the duct, and the rotation direction of the guide vanes is the same as that of the propeller. The aircraft of the present invention is easy to control, and has good flexibility and maneuverability in direction control.

Description

Technical Field

[0001] The present invention relates to a ducted aircraft, and in particular to a single-ducted aircraft. Background Art

[0002] Ducted fan aircraft offer advantages such as compact structure, excellent maneuverability, and strong environmental adaptability. Their application has expanded to military, civilian, and scientific research fields. Due to their promising development prospects, they are gradually attracting the attention of researchers. The structure of a ducted fan UAV includes an annular wing (duct), a propeller disc, a tail rudder, and a fuselage. The annular wing and fan play a vital role in the forward flight of a ducted fan UAV, providing the entire aircraft's propulsion force. During takeoff from a vertical plane, the propeller's reaction force on the air and the additional thrust of the annular wing act together. During forward flight, the yaw, pitch, and roll of a ducted fan aircraft are controlled by the control surfaces. A single ducted aircraft is an independent aircraft capable of independent flight.

[0003] The utility model patented by Patent No. CN201520235559.2 relates to an ultra-small single-ducted fan aircraft, comprising a brushless motor, a ducted fan, a lithium battery, a servo, rudder blades, and landing gear. The ducted fan is located in the center of the aircraft's upper section, with the brushless motor mounted aft of the ducted fan. A double-layered load compartment surrounds the ducted fan, with the lithium battery placed in the upper compartment and the landing gear mounted at the bottom. The servo is connected to the rudder blade shaft and mounted at the bottom of the load compartment. The rudder blades in this utility model are solid structures, resulting in slow and passive control, making them difficult to quickly respond to emergencies in complex and changing flight environments. Furthermore, the reaction force generated by the brushless motor in this utility model causes the ducted fan to rotate in the opposite direction, increasing the difficulty of controlling flight stability. Frequent adjustment of the rudder blades is required to balance the aircraft, hindering flight control. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a single-ducted aircraft which is easy to control and has good flexibility and maneuverability.

[0005] To solve the above technical problems, the technical solution adopted by the present invention is a single-ducted aircraft, which includes an annular duct, a propeller, and four sets of rudder blade mechanisms. The axis of the duct is arranged vertically; the propeller is driven by a driving motor and is arranged in the air duct at the upper part of the duct; the rudder blade mechanisms are arranged at the lower part of the duct and include rudder blades driven by a servo motor. The rudder blade includes an airfoil-shaped plate body and a synthetic jet actuator. The plate body includes an inner cavity and a synthetic jet outlet communicating with the inner cavity. The synthetic jet actuator is installed in the inner cavity of the plate body, and the synthetic jet outlet is close to the trailing edge of the airfoil-shaped plate body; the jet outlet of the synthetic jet actuator communicates with the synthetic jet outlet of the plate body; the air duct at the lower part of the duct includes a plurality of guide vanes, and the guide vanes are fixed on the duct, and the rotation direction of the guide vanes is the same as that of the propeller.

[0006] For the above-mentioned single-ducted aircraft, the duct includes a motor base, and the motor base is arranged in the air duct at the lower part of the duct; the driving motor is fixed on the motor base, and the propeller is fixed at the upper end of the driving motor shaft; a plurality of guide vanes are evenly distributed along the circumference of the duct, the outer ends of the guide vanes are connected to the inner wall of the duct, and the inner ends of the guide vanes are connected to the motor base.

[0007] For the above-mentioned single-ducted aircraft, the helix angle of the guide vane is 80° to 84°; the guide vane, the motor base, and the duct wall are of an integral structure.

[0008] For the above-mentioned single-ducted aircraft, the guide vane adopts an asymmetric airfoil, the outer arc surface or the inner arc surface with a smaller curvature faces upward, and the outer arc surface with a larger curvature faces downward; the leading edge of the guide vane is located at the upper end of the guide vane, and the trailing edge of the guide vane is located at the lower end of the guide vane; the upper part of the side wall of the duct adopts an airfoil-shaped curved surface, the leading edge of the airfoil faces upward, and the diameter of the duct opening at the leading edge is larger than the diameter of the middle part of the duct at the trailing edge; the side wall at the upper part of the duct is of a hollow structure.

[0009] For the above-mentioned single-ducted aircraft, the rudder blade mechanism includes the servo motor, a swing rod, and a swing shaft. The airfoil of the rudder blade plate body is a symmetric airfoil. The plate body includes a swing shaft hole and a hinge hole, and the swing shaft hole and the hinge hole are orthogonal to the longitudinal axis of the plate body; the rudder blade is arranged in the air duct at the lower part of the duct, the symmetry plane of the rudder blade plate body is arranged along the radial direction of the duct, the longitudinal axis of the plate body is arranged vertically, the leading edge of the plate body faces upward, and the trailing edge faces downward; the swing shaft hole is close to the leading edge of the plate body, and the hinge hole is located below the swing shaft hole; the swing shaft passes through the swing shaft hole of the plate body, and the two ends are respectively inserted into the shaft holes on the outer circumference of the motor base and the shaft holes on the side wall of the duct, and a hinge pin is fixed in the hinge hole; the servo motor is fixed on the outer wall of the duct through a servo motor bracket, the drive shaft faces the duct and is coaxial with the swing shaft; one end of the swing rod is fixed on the drive shaft of the servo motor, and the other end is hinged to the hinge pin.

[0010] For the single-ducted aircraft described above, the airfoil of the plate body is a symmetric airfoil. The plate body includes two cover plates, and the two cover plates are buckled with each other in the symmetry plane of the plate body. The buckling surface of the cover plate includes a groove, and the synthetic jet actuator is embedded in the grooves of the two cover plates. The groove near the trailing edge of the plate body includes an opening leading to the arc surface of the plate body, and the openings of the two cover plates form the synthetic jet outlet. The jet outlet of the synthetic jet actuator faces the synthetic jet outlet along the longitudinal direction of the plate body.

[0011] For the single-ducted aircraft described above, the synthetic jet actuator includes a housing and a piezoelectric vibrating diaphragm. The housing includes two pressing plates, and the piezoelectric vibrating diaphragm is clamped between the two pressing plates. The middle part of the piezoelectric vibrating diaphragm includes a piezoelectric ceramic sheet, and the inner surface of the pressing plate includes a groove. The piezoelectric ceramic sheet is located between the grooves of the two pressing plates. The housing includes the jet outlet of the synthetic jet actuator, and the groove of the pressing plate communicates with the jet outlet of the synthetic jet actuator.

[0012] For the single-ducted aircraft described above, it includes a landing gear, two batteries and two control circuit boards. The landing gear is fixed at the lower part of the duct and includes a plurality of legs, and the plurality of legs are evenly distributed along the circumference of the duct. The two batteries are respectively fixed symmetrically on the outer wall of the duct along the diameter direction of the duct through battery racks and are located above the two servos. The two control circuit boards are arranged above the other two servos.

[0013] For the single-ducted aircraft described above, it includes two test hanging plates, and the two hanging plates are symmetrically arranged on the outer wall of the duct along the diameter direction of the duct.

[0014] The single-ducted aircraft of the present invention adopts guide vanes with the same rotation direction as the propeller, which can offset the reverse torque of the duct when the propeller works and reduce the control difficulty of the aircraft. The synthetic jet is used to quickly respond and control the flight direction, so that the flight direction of the single-ducted aircraft can be flexible and changeable, with good maneuverability and rapid control response. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0016] Figure 1 is the front view of the single-ducted aircraft according to the embodiment of the present invention.

[0017] Figure 2 is the top view of the single-ducted aircraft according to the embodiment of the present invention.

[0018] Figure 3 is the side view of the single-ducted aircraft according to the embodiment of the present invention.

[0019] Figure 4 is the bottom view of the single-ducted aircraft according to the embodiment of the present invention.

[0020] Figure 5 is Figure 1 the A-A sectional view in

[0021] Figure 6 is Figure 3 the B-B sectional view in

[0022] Figure 7 is Figure 5 the C-C sectional view in

[0023] Figure 8 is the perspective view of the single-ducted aircraft in the embodiment of the present invention.

[0024] Figure 9 is the front view of the rudder blade in the embodiment of the present invention.

[0025] Figure 10 is the top view of the rudder blade in the embodiment of the present invention.

[0026] Figure 11 is Figure 10 the D-D sectional view in

[0027] Figure 12 is the perspective view of the rudder blade in the embodiment of the present invention.

[0028] Figure 13 is the perspective view of the plate cover of the rudder blade in the embodiment of the present invention.

[0029] Figure 14 is the perspective view of the synthetic jet actuator in the embodiment of the present invention.

[0030] Figure 15 is the front view of the synthetic jet actuator in the embodiment of the present invention.

[0031] Figure 16 is Figure 15 the E-E sectional view in

[0032] Figure 17 is the exploded view of the synthetic jet actuator in the embodiment of the present invention.

[0033] Figure 18 is the sectional view of the flow deflector in the embodiment of the present invention. Detailed implementation manners

[0034] The structure and principle of the single-ducted aircraft in the embodiment of the present invention are as Figures 1 to 18 shown, including an annular duct 10, a right-handed propeller 91, and 4 sets of rudder blade mechanisms 200. The axis of the duct 10 is arranged vertically. The propeller 91 is driven by a driving motor 92 and is arranged in the air duct 10A at the upper part of the duct 10. The driving motor 92 uses a brushless motor and can provide a large driving force.

[0035] The duct 10 includes an annular side wall 11, a motor base 12, a set of guide vanes 13, and two test hanging plates 14. The motor base 12 and the guide vanes 13 are arranged in the air duct 10A at the lower part of the duct 10. The two test hanging plates 14 are symmetrically arranged on the outer wall of the duct 10 along the diameter direction of the duct 10, and there are multiple hanging holes on the hanging plates.

[0036] The driving motor 92 is fixed in the motor base 12 with screws, and the propeller 91 is fixed to the upper end of the main shaft of the driving motor 92. Six guide vanes 13 are evenly distributed along the circumferential direction of the duct 10. The outer ends of the guide vanes 13 are connected to the inner wall of the duct 10, and the inner ends of the guide vanes 13 are connected to the motor base 12. The guide vanes 13, the motor base 12, and the side wall 11 of the duct are an integral structure.

[0037] As Figure 18 shown, the cross-section of the guide vane 13 adopts an asymmetric airfoil, which has a high lift-to-drag ratio and has little influence on the propeller thrust. The outer arc surface (or inner arc surface) 131 with a smaller radian of the guide vane 13 faces upward, and the outer arc surface 132 with a larger radian faces downward. The leading edge of the guide vane 13 is located at the upper end of the guide vane 13, and the trailing edge is located at the lower end of the guide vane 13. The helix angle α of the guide vane 13 is 82° (the inclination angle β is 8°). The rotation direction of the guide vane 13 is right-handed, which is the same as the rotation direction of the propeller 91. The lower end of the airfoil of the guide vane is trimmed, and the fillet R replaces the sharp corner at the lower end of the NACA2410 airfoil to reduce the stress concentration and generate cracks.

[0038] The upper part of the side wall 11 of the duct 10 adopts an airfoil surface, the leading edge of the airfoil faces upward, and the diameter of the duct 10 at the leading edge is larger than the diameter of the duct 10 at the trailing edge. The side wall 11A at the upper part of the duct 10 is a hollow structure.

[0039] The rudder mechanism 200 is arranged at the lower part of the duct 10, and includes a rudder 200A driven by a servo motor 41, a servo motor 41, a swing rod 42, and a hollow swing shaft 43.

[0040] The plate body 20 of the rudder 200A adopts a symmetric airfoil. The plate body 20 includes two cover plates 21, and the two cover plates 21 are buckled with each other on the symmetry plane of the plate body 20. There is a groove 211 on the buckling surface of the cover plate 21, and there is an opening 212A leading to the arc surface of the plate body 20 near the trailing edge of the plate body 20. The openings 212A of the two cover plates 21 form a combined two-way jet outlet 212.

[0041] The synthetic jet actuator 30 includes a housing 31 and a piezoelectric diaphragm 32. The housing 31 includes two pressing plates 31A, and the piezoelectric diaphragm 32 is clamped by the two pressing plates 31A. There is a piezoelectric ceramic sheet 321 in the middle of the piezoelectric diaphragm 32. There is a groove 312 on the inner surface of the pressing plate 31A. The piezoelectric ceramic sheet is located between the grooves 312 of the two pressing plates 31A, and there is a jet flow gap 312A between the piezoelectric ceramic sheet and the bottom surface of the groove 312. One end of the housing 31 has a jet outlet 313 of the synthetic jet actuator, and the jet flow gap 312A communicates with the jet outlet 313 of the synthetic jet actuator 30.

[0042] The synthetic jet actuator 30 is embedded in the inner cavity 211 formed by the combination of the grooves 211 of the two cover plates 21, and the jet outlet 313 of the synthetic jet actuator 30 extends into the synthetic jet outlet 212.

[0043] The plate body 20 has a swing shaft hole 23 and a hinge hole 22, and the swing shaft hole 23 and the hinge hole 22 are orthogonal to the longitudinal axis of the plate body 20. There is a groove 213 communicating between the groove 211 of the cover plate 21 and the swing shaft hole 23, which is convenient for arranging the lead wires of the synthetic jet actuator 30.

[0044] The rudder vane 200A is arranged in the air duct 10A at the lower part of the duct 10. The symmetry plane of the plate body 20 of the rudder vane 200A is arranged along the radial direction of the duct 10. The longitudinal axis of the plate body 20 is arranged vertically, the leading edge of the plate body 20 faces upward, and the trailing edge faces downward. The swing shaft hole 23 of the plate body 20 is close to the leading edge of the plate body 20, and the hinge hole 22 is located below the swing shaft hole 23. The swing shaft 43 passes through the shaft hole on the inner wall of the duct 10, the swing shaft hole 23 of the plate body 20, and is inserted into the shaft hole on the outer periphery of the motor base 12 to form a hinge structure between the rudder vane and the duct. A hinge pin 24 is fixed in the hinge hole 22 of the plate body. The servo 41 is fixed on the outer wall of the duct 10 through a servo bracket 44. The driving shaft of the servo 41 faces the duct 10 and is coaxial with the swing shaft 43. One end of the swing rod 42 is fixed on the driving shaft of the servo 41, and the other end is hinged to the hinge pin 24.

[0045] The landing gear 50 is fixed at the lower part of the duct 10 and includes 4 legs 51, and the 4 legs 51 are evenly distributed along the circumferential direction of the duct 10. Two batteries 53 are respectively fixed on the outer wall of the duct 10 symmetrically along the diameter direction of the duct 10 through battery holders 54, and are located above two symmetric servos 41. Two control circuit boards 55 are arranged above the other two servos 41.

[0046] For the single-ducted aircraft of the above embodiments of the present invention, when the propeller rotates counterclockwise (viewed from above), air is pressed into the air duct of the duct. When the downward-flowing air passes through the guide vanes in the air duct, the circumferential thrust exerted by the air on the guide vanes can balance the reverse torque of the duct. The flowing air passes downward through the rudder under the guide vanes. When the rudder deflects, a low-pressure area will appear in the area on one side of the rudder, and the relatively high pressure next to the low-pressure area will press the air towards the low-pressure area, thereby changing the direction of air flow. The synthetic jet actuator inside the rudder sprays synthetic jets through the vibration of the diaphragm. On the one hand, it can accelerate the generation of the low-pressure area, and on the other hand, it can drive the airflows on both sides, accelerating the deviation of the airflow direction, so as to quickly apply a deflection moment to the aircraft and adjust the deflection angle.

[0047] The single-ducted aircraft of the above embodiments of the present invention adopts guide vanes with the same rotation direction as the propeller, which can offset the reverse torque of the duct during the operation of the propeller and reduce the control difficulty of the aircraft; the synthetic jet is used to quickly respond and actively control the flight direction, making the flight direction of the single-ducted aircraft flexible and variable, having good drivability, and can improve the disadvantage of slow control response of traditional rudder blades.

Claims

1. A single-ducted aircraft, comprising an annular duct, a propeller and four sets of rudder blade mechanisms, the axis of the duct being arranged vertically; the propeller is driven by a driving motor and is arranged in the air duct at the upper part of the duct; the rudder blade mechanisms are arranged at the lower part of the duct and include rudder blades driven by a steering gear, characterized in that, The described rudder flap includes an airfoil-shaped plate body and a synthetic jet actuator. The plate body includes an inner cavity and a synthetic jet outlet communicating with the inner cavity. The synthetic jet actuator is installed in the inner cavity of the plate body, and the synthetic jet outlet is close to the trailing edge of the airfoil-shaped plate body. The jet outlet of the synthetic jet actuator communicates with the synthetic jet outlet of the plate body. In the air duct at the lower part of the duct, there are a plurality of guide vanes. The guide vanes are fixed on the duct, and the rotation direction of the guide vanes is the same as that of the propeller. When the downward-flowing air passes through the guide vanes in the air duct, the circumferential thrust exerted by the air on the guide vanes can balance the reverse torque of the duct. The flowing air passes downward through the rudder flap below the guide vanes. When the rudder flap deflects, a low-pressure area will appear in the area on one side of the rudder flap, and the relatively high pressure next to the low-pressure area will press the air towards the low-pressure area, thereby changing the air flow direction. And the synthetic jet actuator inside the rudder flap ejects a synthetic jet through the vibration of the diaphragm, which can, on the one hand, accelerate the generation of the low-pressure area, and on the other hand, drive the airflows on both sides, accelerating the deviation of the airflow direction, so as to quickly apply a deflection moment to the aircraft and adjust the deflection angle.

2. The single-ducted aircraft according to claim 1, characterized in that, The duct includes a motor base, and the motor base is arranged in the air duct at the lower part of the duct. The driving motor is fixed on the motor base, and the propeller is fixed at the upper end of the driving motor shaft. A plurality of guide vanes are evenly distributed along the circumference of the duct. The outer ends of the guide vanes are connected to the inner wall of the duct, and the inner ends of the guide vanes are connected to the motor base.

3. The single-ducted aircraft according to claim 1, characterized in that, The helix angle of the guide vane is 80° to 84°; the guide vane, the motor base and the duct wall are of an integral structure.

4. The single-ducted aircraft according to claim 1, characterized in that, The guide vane adopts an asymmetric airfoil, with the outer arc surface or the inner arc surface with a smaller radian facing upward, and the outer arc surface with a larger radian facing downward. The leading edge of the guide vane is located at the upper end of the guide vane, and the trailing edge of the guide vane is located at the lower end of the guide vane. The upper part of the side wall of the duct adopts an airfoil-shaped curved surface, with the leading edge of the airfoil facing upward, and the diameter of the duct opening at the leading edge is larger than the diameter of the middle part of the duct at the trailing edge. The upper side wall of the duct is of a hollow structure.

5. The single-ducted aircraft according to claim 2, characterized in that, The rudder flap mechanism includes the described steering gear, swing rod and swing shaft. The airfoil of the rudder flap plate body is a symmetric airfoil. The plate body includes a swing shaft hole and a hinge hole, and the swing shaft hole and the hinge hole are orthogonal to the longitudinal axis of the plate body. The rudder flap is arranged in the air duct at the lower part of the duct. The symmetric plane of the rudder flap plate body is arranged along the radial direction of the duct, the longitudinal axis of the plate body is arranged vertically, the leading edge of the plate body faces upward, and the trailing edge faces downward. The swing shaft hole is close to the leading edge of the plate body, and the hinge hole is located below the swing shaft hole. The swing shaft passes through the swing shaft hole of the plate body and is inserted into the shaft holes on the outer periphery of the motor base and the shaft holes on the side wall of the duct at both ends respectively. A hinge pin is fixed in the hinge hole. The steering gear is fixed on the outer wall of the duct through a steering gear bracket, and the drive shaft faces the duct and is coaxial with the swing shaft. One end of the swing rod is fixed on the drive shaft of the steering gear, and the other end is hinged to the hinge pin.

6. The single-ducted aircraft according to claim 1, wherein The airfoil of the plate body is a symmetric airfoil. The plate body includes two cover plates, and the two cover plates are buckled with each other in the symmetric plane of the plate body. The buckling surface of the cover plate includes a groove, and the synthetic jet actuator is embedded in the grooves of the two cover plates. The groove close to the trailing edge of the plate body includes an opening leading to the arc surface of the plate body, and the openings of the two cover plates form the synthetic jet outlet. The jet outlet of the synthetic jet actuator faces the synthetic jet outlet along the longitudinal direction of the plate body.

7. The single-ducted aircraft according to claim 1, characterized in that The synthetic jet actuator includes a housing and a piezoelectric vibration diaphragm. The housing includes two pressing plates, and the piezoelectric vibration diaphragm is clamped between the two pressing plates. The middle part of the piezoelectric vibration diaphragm includes a piezoelectric ceramic sheet, and the inner surface of the pressing plate includes a groove. The piezoelectric ceramic sheet is located between the grooves of the two pressing plates. The housing includes a jet outlet of the synthetic jet actuator, and the groove of the pressing plate communicates with the jet outlet of the synthetic jet actuator.

8. The single-ducted aircraft according to claim 1, wherein It includes a landing gear, two batteries and two control circuit boards. The landing gear is fixed to the lower part of the duct and includes a plurality of legs, and the plurality of legs are evenly distributed along the circumference of the duct. The two batteries are respectively fixed to the outer wall of the duct symmetrically in the diameter direction of the duct through battery racks and are located above the two servos. The two control circuit boards are arranged above the other two servos.

9. The single-ducted aircraft according to claim 1, wherein It includes two test hanging plates, and the two hanging plates are symmetrically arranged on the outer wall of the duct in the diameter direction of the duct.

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