A high-efficiency and high-maneuverability tandem-wing layout load-carrying aircraft

Abstract

The invention discloses a high-efficiency and high-maneuverability tandem-wing layout load-bearing aircraft, comprising a main beam, a main wing and a vertical tail; the main wing is mounted on the main beam; the main wing comprises a front wing and a rear wing, and the front wing and the rear wing are respectively mounted on the two ends of the main beam; two vertical tails are respectively symmetrically mounted on the left and right ventral surfaces of the rear wing, and a rear landing gear is also mounted on the vertical tail; vertical stabilizing panels are mounted on both ends of the rear wing; the side surfaces of the vertical stabilizing panels are vertically connected and fixed to the length direction of the rear wing; engines are mounted on the two single-sided leading edges of the rear wing, and the propellers of the engines are aligned with the vertical tail; swingable ailerons are mounted on the trailing edges of the front wing, the rear wing and the vertical tail; the landing gear and the vertical tail are integrated and designed to receive the propeller slipstream of the engine to enhance the control of the rudder, and the volume of the aircraft can be reduced; the engine is arranged on the leading edge of the rear wing, so that the propeller slipstream can enhance the control of the rudder through the aileron.

Description

Technical Field

[0001] The present invention relates to the field of aircraft, and in particular to a high-efficiency and high-maneuverability tandem-wing layout load-bearing aircraft. Background Art

[0002] Unmanned aerial vehicles have the characteristics of low operating costs, high maneuverability, convenience and efficiency, and have been successfully used in the logistics industry. However, with the increasing shortage of energy and rising oil prices, the small unmanned aerial vehicles have small load capacity, limited cargo, low operating efficiency, and large unmanned aerial vehicles have high energy consumption and limited urban flight areas. The demand for load-bearing aerial vehicles with small size, strong control performance and high load efficiency is growing.

[0003] Conventional layout small load-carrying unmanned aerial vehicles usually adopt a large aspect ratio design to achieve the purpose of increasing lift and reducing drag, but due to the long wingspan, the requirements for structural strength and stiffness design are relatively high.

[0004] The front and rear wings of a tandem-wing layout aircraft are the main sources of the aircraft's lift. Compared with conventional layout aircraft, it can effectively reduce the wingspan of the front and rear wings and reduce the stiffness requirements of the wing structure.

[0005] Therefore, a technical solution that can improve the load-bearing efficiency of unmanned aerial vehicles is urgently needed. Summary of the invention

[0006] The purpose of the present invention is to provide a high-efficiency and high-maneuverability tandem-wing layout load-bearing aircraft to solve the problem that existing conventional layout aircraft are large in size but have low load-bearing efficiency.

[0007] In order to solve the above technical problems, the present invention provides a high-efficiency and high-maneuverability tandem-wing layout load-bearing aircraft, comprising a main beam, a main wing and a vertical tail; the main wing is installed on the main beam; the main wing comprises a front wing and a rear wing, and the front wing and the rear wing are respectively installed at the two ends of the main beam; the two vertical tails are respectively symmetrically installed on the left and right ventral surfaces of the rear wing, and a rear landing gear is also installed on the vertical tail; vertical stabilizing panels are installed at both ends of the rear wing; the side surfaces of the vertical stabilizing panels are vertically connected and fixed to the length direction of the rear wing; engines are installed on the two single-sided leading edges of the rear wing, and the propellers of the engines are aligned with the vertical tail; swingable ailerons are installed on the trailing edges of the front wing, the rear wing and the vertical tail.

[0008] In one of the embodiments, the main beam is installed between the ventral surface of the front wing and the back surface of the rear wing.

[0009] In one of the embodiments, the main beam is installed between the back surface of the front wing and the ventral surface of the rear wing.

[0010] In one embodiment, the wing difference angle between the front wing and the rear wing is 0.5°-3°; the height difference between the leading edge points of the front wing and the rear wing is 4%-10% of the span of the rear wing; and the span difference between the front wing and the rear wing is 40%-46% of the span of the rear wing.

[0011] In one embodiment, the front wing and the rear wing are both straight wings.

[0012] In one embodiment, the wing area of ​​the main wing is 0.3m 2 -1m 2 ; The wing area of ​​the vertical tail is 0.03m 2 -0.1m 2 .

[0013] In one embodiment, the installation angle of the front wing is 2°-5°, the installation angle of the rear wing is 2°-5°, and the installation angle of the vertical tail is 0°; the aspect ratios of the front wing, the rear wing and the vertical tail are 2-3, 2.5-3.5 and 0.5-1 respectively; the tip-root ratios of the front wing, the rear wing and the vertical tail are 0.3-0.8, 0.2-0.6 and 0.4-0.8 respectively.

[0014] In one of the embodiments, the vertical distance between the chord line of the vertical tail and the main beam is 36%-40% of the single-side wingspan.

[0015] In one embodiment, the wing of the main wing includes a spar and a skin; a plurality of wing ribs are evenly installed in the length direction of the spar; the skin wraps the spar and the wing rib; at the leading edge of the main wing, the spar, the wing rib and the skin form a closed D-shaped box; at the center in the length direction of the main wing, the main wing is installed with an ear piece, and the ear piece is connected and fixed to the main spar; the trailing edge of the main wing is installed with an aileron spar, the aileron spar is connected and fixed to the wing rib, and the aileron is rotatably installed on the aileron spar; the rear wing is provided with an engine compartment, the engine compartment is connected and fixed to the spar, and the engine is installed on the engine compartment.

[0016] In one of the embodiments, the rear landing gear includes a rear wheel and a rear support rod; the vertical tail includes an aileron plate and a vertical wing rib; the rear wheel is rotatably connected to one end of the rear support rod, and the other end of the rear support rod is connected and fixed to the engine compartment; multiple vertical wing ribs are installed along the length direction of the rear support rod; the aileron plate is installed on the trailing edge of the vertical tail, and the aileron plate is connected and fixed to the vertical wing rib; the skin wraps the aileron plate and the vertical wing rib; the aileron is rotatably installed on the aileron plate; a front landing gear is also installed on the main beam, and the front landing gear is installed under the front wing; the front landing gear includes a front wheel and a front support rod; the front wheel is rotatably connected to one end of the front support rod, and the other end of the front support rod is connected and fixed to the main beam.

[0017] The beneficial effects of the present invention are as follows:

[0018] 1. The present invention adopts a tandem wing layout, which simplifies the structural design and improves the compactness of the structure by reducing the aspect ratio and span of the aircraft and integrating the landing gear with the vertical tail without reducing the lift-to-drag ratio and load capacity of the aircraft.

[0019] 2. The center of gravity of the aircraft is placed between the front wing and the rear wing, and the wingspan is reduced to reduce the structural rigidity and strength requirements during the design and production of the aircraft, thereby reducing the structural weight.

[0020] 3. The vertical tail is designed to be installed below and behind the propeller of the engine, and the propeller is installed on the leading edge of the rear wing, so that the ailerons of the vertical tail and the ailerons of the rear wing receive the propeller accelerated airflow to increase the steering effect under low speed and stall conditions.

[0021] 4. The present invention designs a tandem-wing load-bearing aircraft, and the airflow of the front wing and the rear wing has a favorable interference configuration, so as to balance the aircraft without changing the optimal installation angle of the main wing, improve the lift-to-drag ratio and load capacity of the aircraft, and meet the needs of long-range high-efficiency cruising, environmental protection and energy saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the implementation mode will be briefly introduced below. Obviously, the drawings described below are only some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 is a side view of an aircraft according to a first embodiment of the present invention;

[0024] Figure 2 is a schematic diagram of the structure of an aircraft according to a first embodiment of the present invention;

[0025] Figure 3 is a top view of an aircraft according to a first embodiment of the present invention;

[0026] Figure 4 is an axonometric view of an aircraft according to a first embodiment of the present invention;

[0027] Figure 5 is a schematic structural diagram of an aircraft with a load compartment according to a second embodiment of the present invention;

[0028] Figure 6 is a schematic structural diagram of an aircraft frame according to a second embodiment of the present invention;

[0029] Figure 7 is a side view of an aircraft frame according to a second embodiment of the present invention;

[0030] Figure 8 It is a pressure cloud diagram of the CFD simulation results of the wing assembly and vertical tail of the aircraft of the present invention.

[0031] The reference numerals are as follows:

[0032] 1. Main beam; 11. Load compartment;

[0033] 2. Main wing; 21. Front wing; 22. Rear wing; 221. Vertical stabilizer panel; 222. Engine; 23. Vertical tail; 231. Aileron panel; 232. Vertical wing rib;

[0034] 24, wing spar; 241, front wing spar; 242, rear wing spar;

[0035] 25, skin; 251, front wing skin; 252, rear wing skin;

[0036] 26, wing rib; 261, front wing rib; 262, rear wing rib;

[0037] 27, aileron spar; 271, front wing aileron spar; 272, rear wing aileron spar;

[0038] 28. Ear piece; 29. ​​Engine compartment;

[0039] 3. Aileron; 31. Front wing aileron; 32. Rear wing aileron; 33. Vertical tail aileron;

[0040] 4. Rear landing gear; 41. Rear wheel; 42. Rear support rod;

[0041] 5. Front landing gear; 51. Front wheel; 52. Front support rod;

[0042] 6. Front edge;

[0043] 7. trailing edge;

[0044] 8. Ventral surface;

[0045] 9. Back side. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0047] An embodiment of a tandem wing configuration load-carrying aircraft is as follows Figures 1 to 4 As shown, it includes a main beam 1, a main wing 2 and a vertical tail 23; the main wing 2 is installed on the main beam 1; the main wing 2 includes a front wing 21 and a rear wing 22, and the front wing 21 and the rear wing 22 are respectively installed at the two ends of the main beam 1; the two vertical tails 23 are respectively symmetrically installed on the left and right belly surfaces 8 of the rear wing 22, and the vertical tail 23 is also installed with a rear landing gear 4; both ends of the rear wing 22 are installed with a vertical stabilizer panel 221; the side surface of the vertical stabilizer panel is vertically connected and fixed to the length direction of the rear wing 22; engines 222 are installed on the two single-sided leading edges 6 of the rear wing 22, and the propeller of the engine 222 is aligned with the vertical tail 23; swingable ailerons 3 are installed on the trailing edges 7 of the front wing 21, the rear wing 22 and the vertical tail 23.

[0048] In particular, the line of pull of the engine 222 coincides with the chord line of the vertical tail 23;

[0049] Regarding the above professional terms, it is necessary to explain:

[0050] Thrust line: The engine drives the propeller to rotate, generating thrust. The auxiliary line that passes through the thrust point and points in the direction of action is the thrust line.

[0051] Chord line: In the airfoil shape of the wing cross section, the auxiliary line connecting the leading edge point and the trailing edge point of the airfoil profile is the chord line.

[0052] Regarding the installation method of the main beam 1 and the front wing 21 and the rear wing 22, this embodiment is as follows: Figure 1 , Figure 3 and Figure 4 As shown, a main beam 1 is installed between the belly surface 8 of the front wing 21 and the back surface 9 of the rear wing 22.

[0053] When used, the front wing 21 and the rear wing 22 are both integrated wings, and the belly surface 8 of the front wing 21 and the back surface 9 of the rear wing 22 are directly connected and fixed to the main beam 1. In the vertical direction, the front wing 21, the main beam 1 and the rear wing 22 are arranged in order from top to bottom. This wing layout is a tandem front and rear wing layout design, that is, a tandem wing layout.

[0054] It should be noted that the ventral surface 8, dorsal surface 9 and leading edge 6 mentioned above and the trailing edge 7 mentioned below are specifically located as follows: Figure 3 and Figure 4 As indicated, the ventral surface 8 is the lower side surface of the front wing 21 and the rear wing 22, the dorsal surface 9 is the upper side surface of the front wing 21 and the rear wing 22; the leading edge 6 is the front end of the front wing 21, the rear wing 22 and the vertical tail 23, and the trailing edge 7 is the rear end of the front wing 21, the rear wing 22 and the vertical tail 23; the two sides of the rear wing 22 mean that they are divided into left and right sides with the center line of the wing length direction as the dividing line, and the main beam 1 can also be used as the dividing line here.

[0055] The second embodiment of the present invention is basically the same as the first embodiment, except that the installation positions of the main beam 1, the front wing 21 and the rear wing 22 are different. Figure 7 As shown, a main beam 1 is installed between the back surface 9 of the front wing 21 and the belly surface 8 of the rear wing 22.

[0056] When in use, the front wing 21 and the rear wing 22 are both integrated wings, and the back surface 9 of the front wing 21 and the belly surface 8 of the rear wing 22 are directly connected and fixed to the main beam 1. In the vertical direction, the front wing 21, the main beam 1 and the rear wing 22 are arranged in order from bottom to top. This wing layout is also a tandem front and rear wing layout design. This layout additionally adds the design of the load compartment 11. The load layout shown in the figure maximizes the use of the load space.

[0057] It should be noted that if Figures 5 to 7 As shown, in order to facilitate display of the internal structure of the wing, the vertical stabilizer panel 221 of the rear wing 22 is not drawn.

[0058] Regarding the configuration of the main wing 2, this embodiment is as follows Figure 1 , Figure 2 , Figure 5 and Figure 6 As shown, the wing of the main wing 2 includes a spar 24 and a skin 25; a plurality of wing ribs 26 are evenly installed in the length direction of the spar 24; the skin 25 wraps the spar 24 and the wing rib 26; at the leading edge 6 of the main wing 2, the spar 24, the wing rib 26 and the skin 25 form a closed D-shaped box; at the center in the length direction of the main wing 2, the main wing 2 is installed with an ear piece 28, and the ear piece 28 is connected and fixed to the main spar 1; the trailing edge 7 of the main wing 2 is installed with an aileron spar 27, the aileron spar 27 is connected and fixed to the wing rib 26, and the aileron 3 is rotatably installed on the aileron spar 27; an engine compartment 29 is provided on the rear wing 22, the engine compartment 29 is connected and fixed to the spar 24, and the engine 222 is installed on the engine compartment 29.

[0059] Specifically, the spar 24 includes a front wing spar 241 and a rear wing spar 242; the skin 25 includes a front wing skin 251 and a rear wing skin 252; the wing rib 26 includes a front wing rib 261 and a rear wing rib 262; the aileron spar 27 includes a front wing aileron spar 271 and a rear wing aileron spar 272;

[0060] In particular, the wing ribs 26 and the ear pieces 28 are designed to be lightweight, and a plurality of weight-reducing slots are provided on the wing ribs 26 and the ear pieces 28 .

[0061] 1. The front wing 21 is composed of a front wing spar 241, a front wing skin 251, a front wing rib 261 and a front wing aileron spar 271, which are connected in the above-mentioned manner to form the front wing 21.

[0062] 2. The rear wing 22 is composed of a rear wing spar 242, a rear wing skin 252, a rear wing rib 262 and a rear wing aileron spar 272, which are combined into the rear wing 22 in the above-mentioned connection manner, wherein the engine compartment 29 is connected and fixed to the rear wing spar 242.

[0063] 3. As shown in the figure, the engine compartment 29 is rectangular, with one short side end surface connected and fixed to the rear wing spar 242, and the other short side end surface is installed with the engine 222; a plurality of weight-reducing slots are also provided on the plates constituting the engine compartment 29.

[0064] Regarding the above-mentioned landing gear arrangement, this embodiment is as follows Figure 1 , Figure 2 , Figure 5 and Figure 6 As shown, the rear landing gear 4 includes a rear wheel 41 and a rear support rod 42; the vertical tail 23 includes an aileron plate 231 and a vertical wing rib 232; the rear wheel 41 is rotatably connected to one end of the rear support rod 42, and the other end of the rear support rod 42 is connected and fixed to the engine compartment 29; multiple vertical wing ribs 232 are installed along the length direction of the rear support rod 42; the aileron plate 231 is installed on the trailing edge 7 of the vertical tail 23, and the aileron plate 231 is connected and fixed to the vertical wing rib 232; the skin 25 wraps the aileron plate 231 and the vertical wing rib 232; the aileron 3 is rotatably installed on the aileron plate 231; the main beam 1 is also equipped with a front landing gear 5, and the front landing gear 5 is installed under the front wing 21; the front landing gear 5 includes a front wheel 51 and a front support rod 52; the front wheel 51 is rotatably connected to one end of the front support rod 52, and the other end of the front support rod 52 is connected and fixed to the main beam 1.

[0065] When in use, the rear support rod 42 is inserted into the engine compartment 29, and the rear support rod 42 is connected and fixed to the engine compartment 29; the vertical tail 23 is integrated with the rear landing gear 4;

[0066] Beneficial effects: The integrated design of the vertical tail 23 and the rear landing gear 4 can share the function of the vertical stabilizer, reduce structural redundancy, lower the requirements for the structural strength and stiffness of the aircraft, reduce the structural weight and cost of the aircraft, and improve the load ratio.

[0067] In particular, the trailing edges 7 of the front wing 21, the rear wing 22 and the vertical tail 23 are all equipped with swingable ailerons 3, and the ailerons 3 include front wing ailerons 31, rear wing ailerons 32 and vertical tail ailerons 33; therefore, the front wing 21 is equipped with the front wing aileron 31, the rear wing 22 is equipped with the rear wing aileron 32, and the vertical tail 23 is equipped with the vertical tail aileron 33;

[0068] Among them, the front wing aileron 31 and the rear wing aileron 32 have a connecting rod mechanism, and the front wing aileron 31 and the rear wing aileron 32 are rotatably connected with the front wing aileron beam 271 and the rear wing aileron beam 272 respectively through the connecting rod mechanism. By installing a servo on the front wing 21 and the rear wing 22, the connecting rod mechanism is driven, thereby driving the front wing aileron 31 and the rear wing aileron 32 to swing.

[0069] The vertical tail aileron 33 has a connecting rod mechanism, and the vertical tail aileron 33 is rotatably connected to the aileron plate 231 through the connecting rod mechanism. By installing a servo on the vertical tail 23, the connecting rod mechanism is driven, thereby driving the vertical tail aileron 33 to swing.

[0070] Beneficial effects brought about: Since the engine 222 is installed on the leading edge 6 of the rear wing 22, the vertical tail 23 is located below the rear wing 22 to receive the slipstream of the engine 222 propeller, thereby enhancing the control effect of the rudder, and the vertical stabilizer panel 221 that runs through the upper and lower surfaces of the rear wing 22 suppresses the wingtip vortex and reduces induced drag. The front wing 21 and the rear wing 22 rudder surfaces are used in combination to achieve hybrid control, thereby enhancing the rudder effect and lateral stability of the aircraft.

[0071] Design parameters of the front wing 21, rear wing 22 and vertical tail 23 are as follows:

[0072] 1. The wing difference angle between the front wing 21 and the rear wing 22 is 0.5°-3°;

[0073] 2. The height difference between the leading edge 6 points of the front wing 21 and the rear wing 22 is 4%-10% of the span of the rear wing 22;

[0074] 3. The wingspan difference between the front wing 21 and the rear wing 22 is 40%-46% of the wingspan of the rear wing 22;

[0075] 4. Both the front wing 21 and the rear wing 22 are straight wings;

[0076] 5. The wing area of ​​the main wing 2 is 0.3m 2 -1m 2 ;

[0077] 6. The wing area of ​​the vertical tail 23 is 0.03m 2 -0.1m 2 ;

[0078] 7. The installation angle of the front wing 21 is 2°-5°, the installation angle of the rear wing 22 is 2°-5°, and the installation angle of the vertical tail 23 is 0°;

[0079] 8. The aspect ratios of the front wing 21, the rear wing 22 and the vertical tail 23 are 2-3, 2.5-3.5 and 0.5-1 respectively;

[0080] 9. The tip-to-root ratios of the front wing 21, the rear wing 22 and the vertical tail 23 are 0.3-0.8, 0.2-0.6 and 0.4-0.8 respectively;

[0081] 10. The vertical distance between the chord line of the vertical tail 23 and the main beam 1 is 36%-40% of the single-side wingspan.

[0082] It should be noted that

[0083] When applied, the optimal parameters selected for the aircraft actually manufactured by this scheme are:

[0084] 1.1. The wing difference angle between the front wing 21 and the rear wing 22 is 1°;

[0085] 2.1. The height difference between the leading edge of the front wing 21 and the rear wing 22 at six points is 7% of the span of the rear wing 22;

[0086] 3.1. The wingspan difference between the front wing 21 and the rear wing 22 is 43.3% of the wingspan of the rear wing 22;

[0087] 5.1. Wing area of ​​main wing 2: 0.6m 2 ;

[0088] 6.1. The wing area of ​​the vertical tail 23 is 0.06m 2 ;

[0089] 7.1. The installation angle of the front wing 21 is 4°, the installation angle of the rear wing 22 is 3°, and the installation angle of the vertical tail 23 is 0°;

[0090] 8.1, the aspect ratios of the front wing 21, the rear wing 22 and the vertical tail 23 are 2.79, 3.1 and 0.87 respectively;

[0091] 9.1, the tip-to-root ratios of the front wing 21, the rear wing 22 and the vertical tail 23 are 0.6, 0.44 and 0.65 respectively;

[0092] 10.1. The vertical distance between the chord line of the vertical tail 23 and the main beam 1 is 38% of the single-side wingspan.

[0093] Explanation of nouns:

[0094] Wing difference angle: A design indicator for tandem layout aircraft, which refers to the difference in the installation angles of the front and rear wings. For a positive tail, the installation angle of the front wing is greater than that of the rear wing.

[0095] Leading edge point height difference: a design indicator of a tandem layout aircraft, which refers to the distance between the leading edge points of the airfoil of the wing root planing surface of the front and rear wings projected in the vertical direction of the aircraft, representing the relative height of the front and rear wings. If the height difference is positive, the front wing is higher than the rear wing.

[0096] Wingspan difference: A design indicator of a tandem layout aircraft, which characterizes the span of the front and rear wings and is the difference between the span of the front and rear wings.

[0097] Straight wing: A wing without sweep angle. The plan projection shape of this type of wing is symmetrical along the centerline of the wing.

[0098] Installation angle: an aerodynamic design indicator of an aircraft, which refers to the angle between the root chord of the aircraft wing and the center axis of the fuselage. If it is positive, the leading edge of the wing will be tilted directly above the aircraft.

[0099] Aspect ratio: An aerodynamic design indicator of an aircraft, which is the ratio of the wingspan of the aircraft to the average chord length. The larger the aspect ratio, the more slender the fuselage.

[0100] Tip-to-root ratio: An aerodynamic design indicator of an aircraft, which is the ratio of the chord length of the aircraft wing tip to the chord length of the wing root.

[0101] Chord line: In the airfoil shape of the wing cross section, the auxiliary line connecting the leading edge point and the trailing edge point of the airfoil profile is the chord line.

[0102] Beneficial effects:

[0103] (1) By utilizing a tandem wing layout, the load center of gravity of the aircraft is controlled between the front wing 21 and the rear wing 22, thereby widening the cargo mounting point position of the aircraft, making full use of the fuselage space, meeting the demand for large-volume and high-load cargo transportation, and effectively solving the problem of low load efficiency of existing load-carrying aircraft; at the same time, by controlling parameters, the aspect ratio and span of the aircraft are reduced without reducing the lift-to-drag ratio and load capacity of the aircraft.

[0104] (2) In conventional tandem-wing layout load-carrying aircraft, the lift of the rear wing 22 is reduced due to the downwash of the front wing 21.

[0105] The present invention, through design, places the front wing 21 and the rear wing 22 in a spatial position that is favorable for airflow interference, thereby increasing the lift of the aircraft and effectively improving the problem of low load-bearing efficiency of existing load-bearing aircraft.

[0106] (3) Existing tandem wing layout aircraft usually adopts a structural design in which the rear landing gear 4 and the vertical tail 23 are independent, which is complex in structure.

[0107] The present invention integrates the vertical tail 23 on both sides with the rear landing gear 4, installs the vertical tail 23 at the rear and lower part of the engine compartment 29, and integrates the vertical tail 23 with the rear landing gear 4. While receiving the propeller slipstream of the engine 222 to enhance the rudder control effect, it can also serve as a buffer mechanism to reduce the damage to the body structure caused by the impact during the landing phase, greatly reduce the structural weight, and can effectively solve the problems of bloated structure and insufficient structural strength of existing load-bearing aircraft.

[0108] (4) Existing tandem wing layout aircraft achieves aircraft balance by using the front and rear wing angle difference. Usually, due to the balancing requirements, the final wing installation angle is not in a state that can provide maximum lift.

[0109] The present invention utilizes the spatial position configuration of the front wing 21 and the rear wing 22 to achieve zero lift moment balancing of the aircraft, greatly reducing the balancing resistance without changing the optimal installation angles of the front wing 21 and the rear wing 22 or reducing the lift-to-drag ratio of the entire aircraft.

[0110] In addition, the present invention has been subjected to experimental verification flight, and before the experimental flight, an aerodynamic simulation analysis has been performed using fluid analysis software.

[0111] After software analysis, the optimal installation angle of the front and rear wings 22 is obtained. Without changing the optimal installation angle of the wings, the relative spatial position of the front wing 21 and the rear wing 22 is adjusted, and the balancing is verified by software.

[0112] Software calculation verification: Figure 8 As shown in the figure, it can be seen that the upper surfaces of the front wing 21 and the rear wing 22 are low-pressure areas, blue in color, generating suction, and the lower surfaces are reddish, high-pressure areas, generating pressure, and the combined effect generates lift for the aircraft;

[0113] There is a more dramatic color change near the leading edge 6 of the upper surface of the front wing 21, and the blue area is evenly distributed in the span direction, while the color change of the leading edge 6 of the upper surface of the rear wing 22 is not obvious, which shows that the downwash of the front wing 21 suppresses the upper surface of the rear wing 22, increases the pressure, reduces the lift of the rear wing 22, and thus achieves the effect of reducing the nose-down moment trim; the rear wing 22 has an obvious blue area near the wingtip, which is affected by the wingtip vortex of the front wing 21, and the high-energy vortex blows and accelerates the airflow. After software calculation verification, the designed tandem wing layout of the spatial installation position of the front wing 21 and the rear wing 22 has a significant effect on improving the wing lift.

[0114] Test flight verification: The test flight results were successful. The aircraft successfully completed takeoff, conventional route flight, aerobatics, low-altitude pass and landing. The overall flight performance of the aircraft was normal, the flight attitude was stable, and it was able to cruise according to the route. Therefore, it can be proved that the aircraft's balancing plan can be implemented, and it also verifies that the results calculated by the fluid analysis software are basically correct. There were basically no special circumstances in the lateral attitude of the aircraft, verifying that the winglets can improve lateral stability. The successful landing can also prove that the design strength of the aircraft's landing gear and vertical tail meet actual needs.

[0115] The above are preferred embodiments of the present invention. It should be noted that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A high-efficiency and high-maneuverability tandem-wing layout load-carrying aircraft, characterized in that: It includes the main beam, main wing and vertical tail; The main wing is mounted on the main beam; The main wing comprises a front wing and a rear wing, and the front wing and the rear wing are respectively mounted on two ends of the main beam; The two vertical tails are symmetrically mounted on the left and right ventral surfaces of the rear wing, and a rear landing gear is also mounted on the vertical tail; Both ends of the rear wing are equipped with vertical stabilizing panels; the side surfaces of the vertical stabilizing panels are vertically connected and fixed to the length direction of the rear wing; Engines are installed on both single-sided leading edges of the rear wing, and the propellers of the engines are aligned with the vertical tail; The front wing, the rear wing and the trailing edge of the vertical tail are all equipped with swingable ailerons; The wing difference angle between the front wing and the rear wing is 0.5°-3°; The height difference between the leading edge points of the front wing and the rear wing is 4%-10% of the span of the rear wing; The wingspan difference between the front wing and the rear wing is 40%-46% of the wingspan of the rear wing; The front wing and the rear wing are both straight wings; The wing area of ​​the main wing is 0.3 m 2 -1 m 2 ; The wing area of ​​the vertical tail is 0.03 m 2 -0.1 m 2 ; The installation angle of the front wing is 2°-5°, the installation angle of the rear wing is 2°-5°, and the installation angle of the vertical tail is 0°; The aspect ratios of the front wing, the rear wing and the vertical tail are 2-3, 2.5-3.5 and 0.5-1 respectively; The tip-to-root ratios of the front wing, the rear wing and the vertical tail are 0.3-0.8, 0.2-0.6 and 0.4-0.8 respectively.

2. The tandem wing layout load-carrying aircraft according to claim 1, characterized in that: The main beam is installed between the ventral surface of the front wing and the back surface of the rear wing.

3. The tandem wing layout load-carrying aircraft according to claim 1, characterized in that: The main beam is installed between the back surface of the front wing and the ventral surface of the rear wing.

4. The tandem wing layout load-carrying aircraft according to claim 1, characterized in that: The vertical distance between the chord line of the vertical tail and the main beam is 36%-40% of the single-side wingspan.

5. The tandem wing layout load-carrying aircraft according to claim 1, characterized in that: The wing of the main wing includes a spar and a skin; A plurality of wing ribs are evenly installed in the length direction of the spar; The skin wraps the wing spar and the wing rib; At the leading edge of the main wing, the spar, the wing ribs and the skin form a closed D-shaped box; At the center of the main wing in the length direction, the main wing is provided with a lug, and the lug is connected and fixed to the main beam; The trailing edge of the main wing is provided with an aileron spar, the aileron spar is connected and fixed to the wing rib, and the aileron is rotatably mounted on the aileron spar; An engine compartment is provided on the rear wing, the engine compartment is connected and fixed to the wing beam, and the engine is installed on the engine compartment.

6. The tandem wing layout load-carrying aircraft according to claim 5, characterized in that: The rear landing gear includes a rear wheel and a rear support rod; the vertical tail includes an aileron plate and a vertical wing rib; The rear wheel is rotatably connected to one end of the rear support rod, and the other end of the rear support rod is fixedly connected to the engine compartment; The vertical wing ribs are installed in plurality along the length direction of the rear support rod; the aileron plate is installed at the trailing edge of the vertical tail, and the aileron plate is connected and fixed to the vertical wing ribs; the skin wraps the aileron plate and the vertical wing ribs; the aileron is rotatably installed on the aileron plate; A front landing gear is also installed on the main beam, and the front landing gear is installed under the front wing; The front landing gear includes a front wheel and a front support rod; The front wheel is rotatably connected to one end of the front support rod, and the other end of the front support rod is fixedly connected to the main beam.

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