A high-lift coefficient configuration aircraft and method of use thereof

Abstract

The application belongs to the technical field of aircraft design, and particularly relates to a high-lift-coefficient layout aircraft and a use method thereof. The aircraft comprises a fuselage, a hump arranged on an upper middle part of the fuselage, a lower wing connected to the hump, an upper wing located above the lower wing and detachably connected to the lower wing, the upper wing being connected to the lower wing through an actuator and a four-bar linkage mechanism, the separation or adhesion of the upper wing relative to the lower wing being controlled by the actuator, a trailing edge flap and aileron arranged on a trailing edge of the lower wing, a V-tail stabilizer connected to a rear part of the fuselage and a V-tail control surface connected to a tail part of the V-tail stabilizer, and an engine connected to the fuselage. The application can greatly increase wing area and effective angle of attack, and significantly improve take-off and landing lift.

Description

Technical Field

[0001] This application belongs to the field of aircraft design technology, and specifically relates to a high lift coefficient layout aircraft and its usage method. Background Technology

[0002] An aircraft's lift coefficient has a decisive impact on its takeoff and landing performance. During takeoff and landing, to shorten the takeoff and landing distance, the aircraft needs the highest possible maximum lift coefficient. Currently, the mainstream solutions for increasing an aircraft's lift coefficient mainly rely on lift-enhancing devices. Specifically, this involves adding movable wing surfaces, such as leading-edge slats, leading-edge flaps, and Kruger flaps, to the leading and trailing edges of the wings.

[0003] Current technologies primarily rely on altering airfoil camber to increase lift coefficient, but this effect has a physical limit. Excessive camber can lead to airflow separation, causing stall and limiting further increases in maximum lift coefficient. While partially recessed flaps can increase wing area to a limited extent, this increase is localized and linear, failing to achieve a significant leap in total wing area. Constrained by the fixed wing structure, existing configurations cannot provide a substantial increase in effective lift area during takeoff and landing. Summary of the Invention

[0004] To address the aforementioned issues, this application provides a high lift coefficient layout aircraft and its usage method, which overcomes the technical bottlenecks of limited lift enhancement and inability to effectively increase wing area through a more significant aerodynamic shape reconstruction.

[0005] The first aspect of this application provides a high lift coefficient configuration aircraft, mainly comprising:

[0006] body;

[0007] A bulge located in the upper middle section of the fuselage;

[0008] The lower wing connected to the bulge;

[0009] An upper wing located above the lower wing and detachably connected to the lower wing, the upper wing and the lower wing being connected by an actuator and a four-bar linkage, the actuator controlling the separation or attachment of the upper wing relative to the lower wing;

[0010] Trailing edge flaps and ailerons are located on the trailing edge of the lower wing;

[0011] The V-tail stabilizer connected to the rear section of the fuselage and the V-tail control surface connected to the rear of the V-tail stabilizer;

[0012] And the engine connected to the fuselage.

[0013] Preferably, the upper wing is a straight wing with a blunt leading edge and a sharp trailing edge, forming a high lift coefficient airfoil; the lower wing has a sharp leading edge; when the actuator retracts and drives the upper wing and lower wing to fit together, the lower surface of the upper wing and the upper surface of the lower wing fit tightly together, forming a complete streamlined airfoil.

[0014] Preferably, the four-bar linkage includes a front rocker arm, a frame, a rear rocker arm, and a connecting rod. The frame is fixed to the lower wing, with a front lower pivot shaft at the front end along the flight direction and a rear lower pivot shaft at the rear end. The connecting rod is fixed to the upper wing, with a front upper pivot shaft at the front end along the flight direction and a rear upper pivot shaft at the rear end. The front rocker arm is hinged between the front lower pivot shaft and the front upper pivot shaft, and the rear rocker arm is hinged between the rear lower pivot shaft and the rear upper pivot shaft. The fixed end and the telescopic end of the actuator are respectively hinged to the front lower pivot shaft and the rear upper pivot shaft.

[0015] Among the four links of the four-bar linkage, the front rocker arm is the longest, followed by the rear rocker arm, then the connecting rod, and the frame is the shortest.

[0016] Preferably, the lower surface of the upper wing is provided with an upper channel groove in the direction of airflow, and the upper surface of the lower wing is provided with a lower channel groove in the direction of airflow, so as to provide space for the movement of the four-bar linkage.

[0017] Preferably, the chord-direction starting position of the trailing edge flap and aileron is located at the trailing edge point of the upper wing when the upper wing and lower wing are in contact.

[0018] Preferably, the engine is symmetrically connected to the left and right sides of the rear section of the fuselage via a mounting bracket.

[0019] Preferably, the front landing gear is connected to the symmetrical plane of the front section of the fuselage, and the main landing gear is connected to the belly section of the middle section of the fuselage.

[0020] The second aspect of this application provides a method for using a high lift coefficient configuration aircraft as described above, mainly including:

[0021] During takeoff or landing, the actuator is extended to drive the four-bar linkage, causing the upper wing to separate from the lower wing, thereby increasing the total wing area and effective angle of attack and obtaining a high lift coefficient.

[0022] After the aircraft enters the cruise phase, the actuator is controlled to retract, driving the four-bar linkage to rotate and retract the upper wing, which then fits tightly against the lower wing to form a complete streamlined airfoil, thereby reducing flight drag.

[0023] This application can significantly increase the wing area and effective angle of attack, significantly improve takeoff and landing lift, and conform to a streamlined airfoil during cruise, while taking into account both high speed and low drag. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the upper and lower wings fitting together in a preferred embodiment of the high lift coefficient layout aircraft of this application.

[0025] Figure 2 This application Figure 1 The illustrated embodiment shows a schematic diagram of the four-bar linkage in the fitted state.

[0026] Figure 3 This is a schematic diagram showing the separation of the upper and lower wings of a preferred embodiment of the high lift coefficient layout aircraft of this application.

[0027] Figure 4 This application Figure 3 The illustrated embodiment shows a schematic diagram of the four-bar linkage in the disassembled state.

[0028] Figure 5 This is a bottom view of an aircraft according to a preferred embodiment of the high lift coefficient layout aircraft of this application.

[0029] Among them, 1-upper wing, 2-lower wing, 3-bulge, 4-fuselage, 5-nose landing gear, 6-main landing gear, 7-engine, 8-V-tail stabilizer, 9-V-tail control surface, 10-leading edge flap, 11-aileron, 12-front rocker arm, 13-front lower pivot, 14-frame, 15-rear lower pivot, 16-rear rocker arm, 17-actuator, 18-rear upper pivot, 19-linkage, 20-front upper pivot, 21-lower channel slot, 22-hardboard, 23-upper channel slot. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0031] The first aspect of this application provides an aircraft with a high lift coefficient configuration, such as... Figures 1-5 As shown, it mainly includes:

[0032] Fuselage 4;

[0033] The bulge 3 is located on the upper part of the middle section of the body 4;

[0034] The lower wing 2 is connected to the bulge 3;

[0035] An upper wing 1 is located above the lower wing 2 and is detachably connected to the lower wing 2. The upper wing 1 and the lower wing 2 are connected by an actuator 17 and a four-bar linkage. The actuator 17 controls the separation or attachment of the upper wing 1 relative to the lower wing 2.

[0036] Trailing edge flaps 10 and ailerons 11 are located on the trailing edge of the lower wing 2;

[0037] The V-tail stabilizer 8 is connected to the rear section of the fuselage 4, and the V-tail control surface 9 is connected to the rear of the V-tail stabilizer 8;

[0038] And the engine 7 connected to the fuselage 4.

[0039] This application, by configuring an upper wing and a lower wing, allows for takeoffs and landings requiring high lift, such as... Figure 3 As shown, by separating the two wings, the lift coefficient of the aircraft is significantly increased by increasing the wing area, thereby improving the aircraft's takeoff and landing performance. However, in cruise conditions where drag reduction is required, such as... Figure 1 As shown, the upper and lower bases fit together to form a streamlined airfoil.

[0040] The two wings of this application are separated and controlled by actuator 17, and the connection stability between the upper and lower wings is provided by a four-bar linkage mechanism together with actuator 17. The linkage mechanism is driven by actuator 17, and can extend or retract after being driven. When actuator 17 extends, as... Figure 3 and Figure 4 As shown, the upper wing 1 separates from the lower wing 2. When the actuator 17 retracts, as... Figure 1 and Figure 2 As shown, the upper wing 1 and the lower wing 2 are attached together.

[0041] The engine 7 of this application provides power to the aircraft, the trailing edge flap 10 mounted on the lower wing 2 provides lift for takeoff and landing, the aileron 11 provides lateral control for the aircraft, the V-tail stabilizer 8 is connected to the rear section of the fuselage 4, and the V-tail control surface 9 is connected to the trailing edge of the V-tail stabilizer 8 to provide pitch and yaw control for the aircraft.

[0042] In some alternative embodiments, the upper wing 1 is a straight wing with a blunt leading edge, a large airfoil camber, and a sharp trailing edge, forming a high lift coefficient airfoil; the lower wing 2 has a sharp leading edge and a small airfoil camber; when the actuator 17 retracts, driving the upper wing 1 and the lower wing 2 to fit together, the lower surface of the upper wing 1 and the upper surface of the lower wing 2 fit tightly together, combining to form a complete streamlined airfoil.

[0043] like Figure 2 As shown, when the two wings are attached, the attachment surface is streamlined. The starting point of the attachment surface is located at the leading edge of the lower wing 2, and the ending point of the attachment surface is located at the trailing edge of the upper wing 1. After the upper wing 1 and the lower wing 2 are combined, they are naturally attracted by the Bernoulli effect and remain tightly attached.

[0044] In some optional embodiments, the four-bar linkage includes a front rocker arm 12, a frame 14, a rear rocker arm 16, and a connecting rod 19. The frame 14 is fixed to the lower wing 2, with a front lower pivot 13 at the front end along the flight direction and a rear lower pivot 15 at the rear end. The connecting rod 19 is fixed to the upper wing 1, with a front upper pivot 20 at the front end along the flight direction and a rear upper pivot 18 at the rear end. The front rocker arm 12 is hinged between the front lower pivot 13 and the front upper pivot 20, and the rear rocker arm 16 is hinged between the rear lower pivot 15 and the rear upper pivot 18. The fixed end and the telescopic end of the actuator 17 are respectively hinged to the front lower pivot 13 and the rear upper pivot 18.

[0045] Among the four links of the four-bar linkage, the front rocker 12 is the longest, followed by the rear rocker 16, then the link 19, and the frame 14 is the shortest.

[0046] By limiting the dimensions of the aforementioned linkage mechanism, this application enables the aircraft's angle of attack to become adjustable. When the actuator extends, the upper wing 1 separates from the lower wing 2, increasing the effective angle of attack of the upper wing 1. Furthermore, the distance between the upper wing 1 and the lower wing 2 after separation is larger, which is beneficial for obtaining the maximum lift coefficient.

[0047] In some alternative embodiments, the lower surface of the upper wing 1 is provided with an upper channel groove 23 in the direction of airflow, and the upper surface of the lower wing 2 is provided with a lower channel groove 21 in the direction of airflow, to provide space for the movement of the four-bar linkage. In this embodiment, the two channel grooves are vertically opposite each other, both are elongated in shape, and extend in the direction of airflow.

[0048] In some alternative embodiments, the chord-direction starting position of the trailing edge flap 10 and aileron 11 is located at the trailing edge point of the upper wing 1 when the upper wing 1 and lower wing 2 are in contact. For example... Figure 2 As shown, the rear end of the upper surface of the lower wing 2 and the end point of the mating surface of the upper wing 1 are obtuse angle transitions. After the trailing edge of the upper wing 1 falls down, it is located at the obtuse angle transition point, so that the trailing edges of the upper and lower wings are smoothly connected, reducing aerodynamic impact.

[0049] In some alternative implementations, such as Figure 5 As shown, the engine 7 is symmetrically connected to the left and right sides of the rear section of the fuselage 4 via the mounting bracket 22.

[0050] In some alternative embodiments, the front landing gear 5 is connected to the front symmetrical plane of the fuselage 4, and the main landing gear 6 is connected to the mid-section belly of the fuselage 4.

[0051] The second aspect of this application provides a method for using a high lift coefficient configuration aircraft as described above, mainly including:

[0052] During the takeoff or landing phase of the aircraft, the actuator 17 is extended to drive the four-bar linkage, causing the upper wing 1 to separate from the lower wing 2, thereby increasing the total wing area and effective angle of attack and obtaining a high lift coefficient.

[0053] After the aircraft enters the cruise phase, the actuator 17 is controlled to retract, driving the four-bar linkage to rotate and retract the upper wing 1, which then fits tightly with the lower wing 2 to form a complete streamlined airfoil, thereby reducing flight drag.

[0054] The high lift coefficient configuration aircraft provided in this application, during takeoff or landing, is in a... Figure 3 or Figure 4 In its initial state, the upper and lower wings are separated. The lower wing is connected to the fuselage via the wing-fuselage blending bulge, while the upper wing is connected to the lower wing via a four-bar linkage. After experiencing rearward aerodynamic drag, it will balance at the maximum stroke of the actuators. At this time, both the nose landing gear and main landing gear are in the extended position. After takeoff, both the nose and main landing gear retract, the actuators retract, and the upper wing rotates and retracts via the linkage mechanism, engaging with the lower wing to achieve the aircraft's cruise state. Figures 1-2 As shown.

[0055] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A high lift coefficient aircraft, characterized in that, include: fuselage (4); The bulge (3) is located on the upper part of the middle section of the fuselage (4); The lower wing (2) is connected to the bulge (3); An upper wing (1) is located above the lower wing (2) and is detachably connected to the lower wing (2). The upper wing (1) and the lower wing (2) are connected by an actuator (17) and a four-bar linkage. The actuator (17) controls the separation or attachment of the upper wing (1) relative to the lower wing (2). Trailing edge flaps (10) and ailerons (11) are located on the trailing edge of the lower wing (2). The V-tail stabilizer (8) is connected to the rear section of the fuselage (4) and the V-tail control surface (9) is connected to the rear of the V-tail stabilizer (8). And the engine (7) connected to the fuselage (4).

2. The high lift coefficient layout aircraft according to claim 1, characterized in that, The upper wing (1) is a straight wing with a blunt leading edge and a sharp trailing edge, forming a high lift coefficient airfoil; the lower wing (2) has a sharp leading edge; when the actuator (17) retracts and drives the upper wing (1) and the lower wing (2) to fit together, the lower surface of the upper wing (1) and the upper surface of the lower wing (2) fit together tightly, forming a complete streamlined airfoil.

3. The high lift coefficient layout aircraft according to claim 1, characterized in that, The four-bar linkage includes a front rocker arm (12), a frame (14), a rear rocker arm (16), and a connecting rod (19). The frame (14) is fixed to the lower wing (2), with a front lower pivot (13) at the front end along the flight direction and a rear lower pivot (15) at the rear end. The connecting rod (19) is fixed to the upper wing (1), with a front upper pivot (20) at the front end along the flight direction and a rear upper pivot (18) at the rear end. The front rocker arm (12) is hinged between the front lower pivot (13) and the front upper pivot (20), and the rear rocker arm (16) is hinged between the rear lower pivot (15) and the rear upper pivot (18). The fixed end and the telescopic end of the actuator (17) are respectively hinged to the front lower pivot (13) and the rear upper pivot (18). Among the four links of the four-bar linkage, the front rocker (12) is the longest, followed by the rear rocker (16), then the connecting rod (19), and the frame (14) is the shortest.

4. The high lift coefficient layout aircraft according to claim 3, characterized in that, The lower surface of the upper wing (1) is provided with an upper channel groove (23) in the direction of airflow, and the upper surface of the lower wing (2) is provided with a lower channel groove (21) in the direction of airflow, which provides space for the movement of the four-bar linkage.

5. The high lift coefficient layout aircraft according to claim 1, characterized in that, The trailing edge flap (10) and aileron (11) are located at the trailing edge point of the upper wing (1) when the upper wing (1) and the lower wing (2) are in contact.

6. The high lift coefficient layout aircraft according to claim 1, characterized in that, The engine (7) is symmetrically connected to the left and right sides of the rear section of the fuselage (4) via a mounting bracket (22).

7. The high lift coefficient layout aircraft according to claim 1, characterized in that, The front landing gear (5) is connected to the front symmetrical plane of the fuselage (4), and the main landing gear (6) is connected to the middle belly of the fuselage (4).

8. A method of using a high lift coefficient configuration aircraft as described in any one of claims 1-7, characterized in that, include: During the takeoff or landing phase of the aircraft, the actuator (17) is extended to drive the four-bar linkage, causing the upper wing (1) to separate from the lower wing (2) in order to increase the total wing area and effective angle of attack and obtain a high lift coefficient. After the aircraft enters the cruise phase, the actuator (17) is controlled to retract, driving the four-bar linkage to rotate and retract the upper wing (1), which then fits tightly with the lower wing (2) to form a complete streamlined airfoil, thereby reducing flight drag.

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