A single-swept flying wing and horizontal tail fusion aerodynamic layout aircraft

Abstract

The present application belongs to the field of aircraft aerodynamic layout design, and particularly relates to a single-swept flying wing and horizontal tail integrated aerodynamic layout aircraft. The aircraft comprises a flying wing (1) and a horizontal tail (2), the trailing edge of the flying wing (1) comprises a first trailing edge and a second trailing edge respectively parallel to the left and right leading edges of the flying wing, the horizontal tail (2) is directly behind the central axis of the flying wing and symmetrically arranged on both sides of the central axis; a drag rudder (7) and an outer flaperon (8) are arranged on the first trailing edge, an inner flaperon (9) is arranged on the second trailing edge, and an elevator (10) is arranged on the side close to the leading edge of the horizontal tail at the trailing edge (22) of the horizontal tail; the flying wing (1) and the horizontal tail (2) adopt the same leading and trailing edge sweep angles, the tail of the flying wing (1) overlaps the front of the horizontal tail (2), and the upper and lower surfaces at the junction of the flying wing (1) and the horizontal tail (2) are smoothly transitioned. The present application improves the longitudinal static stability and maneuverability of the aircraft while taking into account higher structural efficiency and aerodynamic efficiency.

Description

Technical Field

[0001] The present application belongs to the field of aircraft aerodynamic layout design, and in particular relates to a single-swept flying wing and horizontal tail fusion aerodynamic layout aircraft. Background Art

[0002] With the rapid development of detection technology, guidance technology and strike technology, the new generation of military aircraft such as bombers, fighters and reconnaissance aircraft are facing increasingly severe challenges in survivability. Flying wing layout aircraft adopts an integrated design of wings and fuselage, with excellent stealth performance, high structural efficiency and aerodynamic efficiency. The flying wing layout has become the preferred aerodynamic layout for these military aircraft, but the longitudinal static stability and maneuverability of flying wing layout aircraft are insufficient, generally showing static instability or neutral stability. After stalling, the pitch control rudder is located in the flow separation zone, the rudder fails or is inefficient, and it is difficult to recover in time and effectively. At present, it is mainly solved by the design of the flight control system, but it relies too much on the flight control system to achieve stability enhancement and control, and the safety and reliability of the aircraft need to be further improved. On the other hand, it relies on subsystems such as sensors, flight control software, actuation systems, and control rudders, and is constrained by conditions such as rudder deflection rate, rudder efficiency, and deflection authority. Overall, the complexity of the system is greatly increased, and the safety and reliability of the aircraft are reduced.

[0003] Due to the high stealth requirement, the flying wing layout aircraft needs to bury the relatively long engine and its intake and exhaust system into the fuselage, and take into account the shielding of the air inlet and exhaust port, which causes the size of the middle fuselage to be lengthened. The single-swept flying wing layout with the best stealth effect will result in too large a wing area and too low a wing load, making it difficult to achieve good high-speed cruise flight performance. The use of double-swept flying wing layouts to lengthen the middle fuselage will lead to a significant decrease in the stealth performance of the aircraft, a decrease in the maximum lift coefficient, and the inflection point of the longitudinal moment coefficient curve will appear too early and pitch up, making it difficult for the overall performance of the aircraft to meet expectations.

[0004] The improved design of the flying wing aerodynamic layout that has high stealth performance, high structural efficiency and aerodynamic efficiency, meets the requirements of the intake and exhaust system layout, improves longitudinal static stability and maneuverability, and can promptly and effectively recover from stall has become a difficult point in the research of the new generation of military aircraft. Summary of the invention

[0005] In order to solve at least one of the above technical problems, the present application designs a single-swept flying wing and horizontal tail fusion aerodynamic layout aircraft, which mainly includes:

[0006] A flying wing and a horizontal tail, wherein the flying wing is a single-swept flying wing, and is symmetrically designed along the central axis. On either side of the central axis, the trailing edge of the flying wing includes a first trailing edge and a second trailing edge which are respectively parallel to the leading edges on the left and right sides. The first trailing edge extends forward from the wing tip to the wing inflection point in parallel with the leading edge of the flying wing on that side, and the second trailing edge extends from the wing inflection point in parallel with the leading edge of the flying wing on the other side in the direction of the central axis to the intersection point connected with the horizontal tail. The horizontal tail is directly behind the central axis of the flying wing and is symmetrically arranged on both sides of the central axis. The leading edge of the horizontal tail on either side extends backward in parallel with the first trailing edge of the flying wing on that side, and the trailing edge of the horizontal tail on either side extends in the direction of the central axis in parallel with the second trailing edge of the flying wing on that side, and the trailing edges of the horizontal tail on both sides of the central axis meet at the central axis.

[0007] Wherein, a drag rudder and an outer flaperon are arranged on the first trailing edge, an inner flaperon is arranged on the second trailing edge, and an elevator is arranged on the trailing edge of the horizontal tail near the leading edge of the horizontal tail; the flying wing and the horizontal tail adopt the same leading and trailing edge sweep angles, the tail of the flying wing overlaps the front of the horizontal tail, and the upper and lower surfaces at the junction of the flying wing and the horizontal tail are smoothly transitioned;

[0008] The engine of the aircraft is arranged inside the aircraft along the central axis, with an engine air inlet on the front side and an engine exhaust pipe extending to the trailing edge of the horizontal tail on the rear side.

[0009] Preferably, the center of gravity of the aircraft is arranged at a position of the engine close to the engine air intake.

[0010] Preferably, the dihedral angle of the horizontal tail is set within the range of -5° to 5°.

[0011] Preferably, the drag rudder is arranged at a position of the first trailing edge close to the wing tip, and the outer flaperon is arranged at a position of the first trailing edge close to the wing inflection point.

[0012] Preferably, the engine exhaust port at the rear side of the engine exhaust pipe is located between the elevators on both sides of the horizontal tail.

[0013] Preferably, the multiple airfoils of the flying wing with different span directions are connected and transitioned smoothly in the span direction, and the multiple airfoils of the horizontal tail with different span directions are connected and transitioned smoothly in the span direction.

[0014] The present application enables the aircraft to obtain high stealth performance, meet the requirements of the intake and exhaust system layout, improve longitudinal static stability and maneuverability, while taking into account higher structural efficiency and aerodynamic efficiency, enhancing the stall recovery capability, and improving the overall comprehensive performance of the aircraft, reducing the dependence on the flight control system, system complexity and development costs, and improving the safety and reliability of the aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1It is a top view of a preferred embodiment of the single-swept flying wing and horizontal tail fusion aerodynamic layout aircraft of the present application.

[0016] Figure 2 It is a cross-sectional airfoil diagram at the symmetry plane of the flying wing after the flying wing and horizontal tail are integrated into one design.

[0017] Figure 3 It is a cross-sectional airfoil diagram of the horizontal tail before and after the intersection of the horizontal tail and the flying wing.

[0018] Figure 4 Airfoil diagram of the wing cross section at the inflection point of the wing.

[0019] Figure 5 It is a schematic diagram of the cross-section airfoil at the wingtip of a flying wing.

[0020] Among them, 1-flying wing, 2-horizontal tail, 3-center of gravity of the whole aircraft, 4-engine, 5-engine air inlet, 6-engine exhaust pipe, 7-drag rudder, 8-outer flaperon, 9-inner flaperon, 10-elevator, 11-engine exhaust port, 12-flying wing inflection point, 13-junction point, 14-wingtip, 21-horizontal tail leading edge, 22-horizontal tail trailing edge. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the implementation of this application will be described in more detail in combination with the drawings in the implementation of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described implementation is a part of the implementation of this application, not all of the implementations. The implementation described below with reference to the drawings is exemplary and is intended to be used to explain this application, and cannot be understood as a limitation on this application. Based on the implementation in this application, all other implementations obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The implementation of this application is described in detail below in combination with the drawings.

[0022] The present application provides a single-swept flying wing and horizontal tail fusion aerodynamic layout aircraft, such as Figure 1 As shown, it mainly includes:

[0023] A flying wing 1 and a horizontal tail 2, wherein the flying wing is a single-swept flying wing, and is symmetrically designed along the central axis. On either side of the central axis, the trailing edge of the flying wing 1 includes a first trailing edge and a second trailing edge which are respectively parallel to the leading edges on the left and right sides, the first trailing edge extending forward from the wing tip 14 in parallel with the leading edge of the flying wing on that side to the flying wing inflection point 12, the second trailing edge extending from the flying wing inflection point 12 in parallel with the leading edge of the flying wing on the other side in the direction of the central axis to the intersection point 13 connected with the horizontal tail 2, the horizontal tail 2 is directly behind the central axis of the flying wing, and is symmetrically arranged on both sides of the central axis, the leading edge 21 of the horizontal tail on either side extends backward in parallel with the first trailing edge of the flying wing on that side, the trailing edge 22 of the horizontal tail on either side extends in the direction of the central axis in parallel with the second trailing edge of the flying wing on that side, and the trailing edges of the horizontal tails on both sides of the central axis meet at the central axis;

[0024] The first trailing edge is provided with a drag rudder 7 and an outer flaperon 8, the second trailing edge is provided with an inner flaperon 9, and the trailing edge 22 of the horizontal tail is provided with an elevator 10 on a side close to the leading edge of the horizontal tail; the flying wing 1 and the horizontal tail 2 adopt the same leading and trailing edge sweep angles, the tail of the flying wing 1 overlaps the front of the horizontal tail 2, and the upper and lower surfaces at the junction of the flying wing 1 and the horizontal tail 2 are smoothly transitioned;

[0025] The engine 4 of the aircraft is arranged inside the aircraft along the central axis, with an engine air inlet 5 at the front side and an engine exhaust pipe 6 extending to the trailing edge 22 of the horizontal tail at the rear side.

[0026] like Figure 1 As shown, it is different from the existing single-swept aerodynamic layout aircraft, double-swept aerodynamic layout aircraft, or other aerodynamic layout aircraft with a separate horizontal tail design. Specifically, the single-swept flying wing and horizontal tail are integrated into a single-swept flying wing, and the leading and trailing edges of the flying wing, the wingtip edge of the wing, the leading and trailing edges of the horizontal tail, and the edges of all control surfaces have equal sweep angles, ranging from 20° to 70°. Figure 2 As shown, the front part of the horizontal tail 2 overlaps with the tail part of the flying wing 1, with a smooth transition and a fusion design, which provides sufficient layout space for the intake and exhaust systems.

[0027] The single-swept flying wing and horizontal tail fusion aerodynamic layout provided by the present application fully utilizes the high stealth, high structural efficiency and high aerodynamic efficiency characteristics of the single-swept flying wing aerodynamic layout and the characteristics of the horizontal tail's "mid-fuselage" lengthening, improved longitudinal static stability and maneuverability, and enhanced stall recovery capability through an integrated design in which the edges of the flying wing and the horizontal tail are parallel and fused. The flying wing and the horizontal tail provide aerodynamic force as a whole, and when the horizontal tail is trimmed, the adverse interference to the aerodynamic force of the flying wing is smaller, and the lift loss of the entire aircraft is smaller, which solves the problems existing in single-swept flying wing layout aircraft, double-swept flying wing layout aircraft, and other aerodynamic layout aircraft that adopt a separate horizontal tail design.

[0028] The single-swept flying wing and horizontal tail are integrated into a single-swept flying wing. The flying wing and horizontal tail are integrated as a whole. Their stealth performance, lift characteristics, lateral stability and maneuverability are equivalent to those of a single-swept flying wing. The longitudinal static stability increases by about 10% to 120% with the increase of the angle of attack, the longitudinal maneuverability increases by about 60%, and the maximum lift-to-drag ratio decreases by less than 5%. This allows the aircraft to obtain high stealth performance, meet the requirements of the intake and exhaust system layout, improve longitudinal static stability and maneuverability, while taking into account higher structural efficiency and aerodynamic efficiency, enhancing the ability to recover from stall, improving the overall comprehensive performance of the aircraft, reducing the dependence on the flight control system, system complexity and development costs, and improving the safety and reliability of the aircraft.

[0029] In some optional embodiments, reference Figure 1 The center of gravity 3 of the aircraft is arranged at a position of the engine 4 close to the engine air intake 5 .

[0030] In some optional embodiments, the dihedral angle of the horizontal tail 2 is set within a range of -5° to 5°.

[0031] In some optional embodiments, reference Figure 1 The drag rudder 7 is arranged at a position of the first trailing edge close to the wing tip 14, and the outer flaperon 8 is arranged at a position of the first trailing edge close to the wing inflection point 12.

[0032] In some optional embodiments, the engine exhaust port 11 at the rear side of the engine exhaust pipe 6 is located between the elevators 10 on both sides of the horizontal tail 2. Specifically, the engine 4, the engine air intake 5, and the engine exhaust pipe 6 are embedded in the fuselage, and the engine exhaust port 11 extends to the rear of the upper surface of the tail.

[0033] In some optional embodiments, multiple airfoils of different span directions of the flying wing are connected and transitioned smoothly in the span direction, and multiple airfoils of different span directions of the horizontal tail are connected and transitioned smoothly in the span direction.

[0034] In this embodiment, when designing the single-swept flying wing and horizontal tail fusion aerodynamic layout aircraft of the present application, firstly, according to the length of the engine 4, the engine air inlet 5, the engine exhaust pipe 6 and the required front and rear wing surface lengths, the total length from the leading edge point of the flying wing 1 to the trailing edge point of the horizontal tail 2 is calculated, the area, leading and trailing edge sweep angles, span, dihedral angle, installation angle, torsion angle and spanwise position of the flying wing inflection point 12 of the flying wing 1 are determined, and a top view plan view of the flying wing 1 is drawn. Then, the leading and trailing edge sweep angles that are the same as those of the flying wing 1 are selected, the area, span, installation angle, torsion angle and longitudinal position of the horizontal tail and the wing intersection 13 of the horizontal tail 2 are determined, the dihedral angle within the range of -5° to 5° is selected, and a top view plan view of the horizontal tail 2 is drawn. First, 1 to 8 spanwise airfoils are configured for the flying wing 1, and a three-dimensional model of the flying wing 1 is designed through spanwise and segmented smooth connection and transition. Figure 4 and Figure 5 The airfoil diagrams of two parts are given; then 1 to 4 spanwise airfoils are configured for the horizontal tail 2, and the three-dimensional models of the horizontal tail 2 are designed respectively through spanwise smooth connection and transition; finally, the horizontal tail 2 is moved to the longitudinal position of the intersection point 13 of the horizontal tail and the flying wing, and the upper surface of the rear part of the flying wing 1 and the upper part of the horizontal tail 2 are connected and blended through a smooth curved surface. Similarly, the lower surface of the rear part of the flying wing 1 and the lower part of the horizontal tail 2 are connected and blended through a smooth curved surface to form an integrated design, such as Figure 2-Figure 3 shown.

[0035] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A single-swept flying wing and horizontal tail fusion aerodynamic layout aircraft, It is characterized in that The invention comprises a flying wing (1) and a horizontal tail (2), wherein the flying wing is a single-swept flying wing and is symmetrically designed along a central axis. On either side of the central axis, the trailing edge of the flying wing (1) comprises a first trailing edge and a second trailing edge which are respectively parallel to the left and right leading edges. The first trailing edge extends forward from the wing tip (14) in a direction parallel to the leading edge of the flying wing on that side to a flying wing inflection point (12). The second trailing edge extends from the flying wing inflection point (12) in a direction parallel to the leading edge on the other side in a direction toward the central axis to a junction point (13) connected with the horizontal tail (2). The horizontal tail (2) is directly behind the central axis of the flying wing and is symmetrically arranged on both sides of the central axis. The leading edge (21) of the horizontal tail on either side extends backward in a direction parallel to the first trailing edge of the flying wing on that side. The trailing edge (22) of the horizontal tail on either side extends in a direction parallel to the second trailing edge of the flying wing on that side in a direction toward the central axis. The trailing edges of the horizontal tail on both sides of the central axis meet at the central axis. Wherein, a drag rudder (7) and an outer flaperon (8) are arranged on the first trailing edge, an inner flaperon (9) is arranged on the second trailing edge, and an elevator (10) is arranged on the trailing edge (22) of the horizontal tail near the leading edge of the horizontal tail; the flying wing (1) and the horizontal tail (2) adopt the same leading and trailing edge sweep angles, the tail of the flying wing (1) overlaps the front of the horizontal tail (2), and the upper and lower surfaces at the junction of the flying wing (1) and the horizontal tail (2) are smoothly transitioned; The engine (4) of the aircraft is arranged inside the aircraft along the central axis, and has an engine air inlet (5) on the front side and an engine exhaust pipe (6) extending to the trailing edge (22) of the horizontal tail on the rear side; The dihedral angle of the horizontal tail (2) is set within a range of -5° to 5°; The drag rudder (7) is arranged at a position of the first trailing edge close to the wing tip (14), and the outer flaperon (8) is arranged at a position of the first trailing edge close to the wing inflection point (12).

2. The single-swept flying wing and horizontal tail fusion aerodynamic layout aircraft according to claim 1, It is characterized in that The center of gravity (3) of the aircraft is arranged at a position of the engine (4) close to the engine air intake (5).

3. The single-swept flying wing and horizontal tail fusion aerodynamic layout aircraft according to claim 1, It is characterized in that The engine exhaust port (11) at the rear side of the engine exhaust pipe (6) is located between the elevators (10) on both sides of the horizontal tail (2).

4. The single-swept flying wing and horizontal tail fusion aerodynamic layout aircraft according to claim 1, It is characterized in that The multiple airfoils of the flying wing with different span directions are connected and transitioned smoothly in the span direction; the multiple airfoils of the horizontal tail with different span directions are connected and transitioned smoothly in the span direction.

Images