Wing knife type vortex generator for improving flying wing steering effect in large attack angle state

Abstract

The invention provides a wing knife type vortex generator for improving the steering effect of a flying wing in a large attack angle state, a wing of the flying wing comprises a leading edge, a wing root for arranging a convex molded surface of a fuselage and a trailing edge for arranging a deflection flap, the leading edge, the wing root and the trailing edge are connected in sequence, and the wing knife type vortex generator comprises a wing knife type vortex generator body, the winged knife type vortex generator body is arranged on the leeside of a wing, and the winged knife type vortex generator body is arranged close to the front edge; wherein in a large attack angle state, the wing knife type vortex generator body is used for being combined with a convex molded surface of a wing root to construct a local spray pipe-like area close to a leeside, so that a local flow field on the surface of a deflection flap at a tail edge is changed into an appendage state from a separation state. According to the wing knife type vortex generator for improving the steering effect of the flying wing in the large attack angle state, the wing knife type vortex generator body is arranged on the wing, so that the steering effect of the wing flap can be effectively improved, and the effect of reducing the head-up torque is achieved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of aircraft, and in particular to a wing-shaped vortex generator for improving the rudder effect of a flying wing at a large angle of attack. Background Art

[0002] When a tailless flying wing aircraft performs high angle of attack maneuvers, the leading edge flow vortex that generates vortex lift usually breaks up in advance, causing a large area of ​​flow separation on the leeward side. Large-scale flow separation brings two adverse effects: the lift of the fuselage decreases and the drag increases, while the lift, drag and pitch moment enter a nonlinear section with the change of the angle of attack; the rudder effect of control devices such as elevators and flaperons is reduced, making it difficult to suppress the aircraft's tendency to lift up, and the longitudinal stability of the aircraft is difficult to control.

[0003] There are generally two solutions to the control problem at large angles of attack: one is to use the engine vector nozzle for direct control, and directly adjust the aerodynamic performance by adjusting the thrust direction; the other is to control the separation flow field and vortex, and improve the aerodynamic performance by improving the flow field quality, which is divided into active control methods of injecting energy into the flow field and passive control methods of changing the geometric shape.

[0004] At present, the above three methods have been widely studied, but difficulties have arisen in practical applications: the difficulties of vector nozzles include control accuracy, response delay, thrust loss, etc.; the difficulties of active control methods such as blowing and suction, and ionization control include complex structure, large energy requirements, and engine intake volume restrictions; passive control methods such as the use of V-tail, Guney wing and other control devices can achieve better control effects, but such large-scale components will destroy the stealth effect of the fuselage, which is contrary to the original design intention of the aircraft. Summary of the invention

[0005] The present disclosure aims to solve one of the technical problems in the related art at least to some extent.

[0006] To this end, the purpose of the present disclosure is to provide a wing-type vortex generator that improves the rudder effect of a flying wing at a large angle of attack.

[0007] To achieve the above-mentioned purpose, the present disclosure provides a wing-type vortex generator for improving the rudder effect of a flying wing under a large angle of attack state, wherein the wing of the flying wing comprises: a leading edge, a wing root on which a convex profile of a fuselage is arranged, and a trailing edge on which a deflection flap is arranged, wherein the leading edge, the wing root, and the trailing edge are connected in sequence, and the wing-type vortex generator comprises: a wing-type vortex generator body, wherein the wing-type vortex generator body is arranged on the leeward side of the wing, and the wing-type vortex generator body is arranged close to the leading edge; wherein, when the angle of attack is large, the wing-type vortex generator body is used to combine with the convex profile of the wing root to construct a local nozzle-like area close to the leeward side, so as to accelerate the attached airflow of the leeward side, thereby changing the local flow field on the deflection flap surface of the trailing edge from a separated state to an attached state.

[0008] Optionally, the blade-type vortex generator body includes: a flat plate, which is arranged on the leeward side of the wing and is arranged close to the leading edge; wherein the length of the flat plate along the direction of the attached airflow on the leeward side and the length of the wing root are in a first preset ratio; the height of the flat plate along the normal to the leeward side and the length of the wing root are in a second preset ratio; the spacing between the flat plate and the wing root and the span-wise length of the wing are in a third preset ratio; and the flat plate and the wing root are in a preset angle.

[0009] Optionally, the height of the flat plate is greater than the height of the vortex core of the leading edge vortex at the flat plate.

[0010] Optionally, the distance between the flat plate and the leading edge is not greater than the height of the flat plate along the normal direction of the leeward surface.

[0011] Optionally, the first preset ratio between the length of the flat plate along the direction of the attached airflow on the leeward surface and the length of the wing root is in a range of 1%-10%.

[0012] Optionally, the second preset ratio between the height of the flat plate along the normal direction of the leeward surface and the length of the wing root is in a range of 0.5% to 2%.

[0013] Optionally, the third preset ratio between the spacing between the flat plate and the wing root and the span-wise length of the wing is 50%.

[0014] Optionally, a preset angle range between the flat plate and the wing root is -10° to 10°.

[0015] The technical solution provided by the present disclosure may have the following beneficial effects:

[0016] Since the wing-type vortex generator body is arranged on the leeward side of the wing, and the wing-type vortex generator body is arranged close to the leading edge, when the flying wing is in a state of large angle of attack, the wing-type vortex generator body can be combined with the convex profile of the wing root, and a local nozzle-like area close to the leeward side is constructed between the wing-type vortex generator body and the convex profile of the wing root, thereby accelerating the attached airflow on the leeward side, and then changing the local flow field on the deflection flap surface of the trailing edge from a separated state to an attached state. Therefore, by arranging the wing-type vortex generator body on the wing, the rudder effect of the flap can be effectively improved, and the effect of reducing the nose-up moment can be achieved. In addition, the overall passive geometric shape improvement on the leeward side of the wing can be compatible with the stealth design of the aircraft while improving the flight stability, and has a lower processing difficulty.

[0017] Additional aspects and advantages of the present disclosure will be given in part in the following description and in part will be obvious from the following description or learned through practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present disclosure will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0019] Figure 1 It is a structural schematic diagram of a wing-shaped vortex generator for improving the rudder effect of a flying wing at a large angle of attack, proposed in one embodiment of the present disclosure;

[0020] Figure 2 It is a structural schematic diagram of a wing-shaped vortex generator for improving the rudder effect of a flying wing at a large angle of attack proposed in an embodiment of the present disclosure (airflow distribution when the wing-shaped vortex generator body is not provided);

[0021] Figure 3 It is a structural schematic diagram of a wing-shaped vortex generator for improving the rudder effect of a flying wing at a large angle of attack proposed in an embodiment of the present disclosure (airflow distribution when a wing-shaped vortex generator body is provided);

[0022] Figure 4 is a schematic structural diagram of a flying wing proposed in an embodiment of the present disclosure;

[0023] As shown in the figure: 1. Wing, 11. Leading edge, 12. Wing root, 13. Trailing edge, 14. Leeward side,

[0024] 2. Wing-type vortex generator body. DETAILED DESCRIPTION

[0025] Embodiments of the present disclosure are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present disclosure, and should not be construed as limitations on the present disclosure. On the contrary, the embodiments of the present disclosure include all changes, modifications and equivalents that fall within the spirit and connotation of the appended claims.

[0026] like Figure 1 As shown, the embodiment of the present disclosure proposes a wing blade type vortex generator for improving the rudder effect of a flying wing at a large angle of attack. The wing 1 of the flying wing includes: a leading edge 11, a wing root 12 with a convex profile of the fuselage, and a trailing edge 13 with a deflection flap. The leading edge 11, the wing root 12 and the trailing edge 13 are connected in sequence. The wing blade type vortex generator includes: a wing blade type vortex generator body 2, which is arranged on the leeward side 14 of the wing 1, and the wing blade type vortex generator body 2 is arranged close to the leading edge 11. In the large angle of attack state, the wing blade type vortex generator body 2 is used to combine the convex profile of the wing root 12 to construct a local nozzle-like area close to the leeward side 14, so as to accelerate the attached airflow of the leeward side 14, thereby changing the local flow field of the deflection flap surface of the trailing edge 13 from a separated state to an attached state.

[0027] It can be understood that since the wing-type vortex generator body 2 is arranged on the leeward side 14 of the wing 1 and the wing-type vortex generator body 2 is arranged close to the leading edge 11, when the flying wing is in a large angle of attack state, the wing-type vortex generator body 2 can be combined with the convex surface of the wing root 12 to construct a local nozzle-like area close to the leeward side 14 between the wing-type vortex generator body 2 and the convex surface of the wing root 12, thereby accelerating the attached airflow on the leeward side 14, and then changing the local flow field on the deflection flap surface of the trailing edge 13 from a separated state to an attached state.

[0028] Therefore, by arranging the blade-type vortex generator body 2 on the wing 1, the rudder effect of the flap can be effectively improved, and the effect of reducing the nose-up moment can be achieved. In addition, the overall passive geometric shape improvement is adopted on the leeward side 14 of the wing 1, which can improve the flight stability while being compatible with the stealth design of the aircraft and has a lower processing difficulty.

[0029] It should be noted that the wing-type vortex generator body 2 arranged near the leading edge is used to inject energy into the boundary layer of the downstream flow field, so that the local flow field on the upper surface of the deflection flap is changed from a separated state to an attached state, thereby improving the rudder effect to achieve a control effect. Specifically, the wing-type vortex generator body 2 not only accelerates the airflow of the leading edge part by limiting the spanwise flow of the leading edge part, but also improves the pressure distribution on the outside by forming a new flow vortex on the outside.

[0030] When the wing-type vortex generator body 2 is used in an aircraft at a large angle of attack, it can not only improve the flap rudder effect, but also does not consume engine energy, is compatible with stealth design and structural design, is easy to process and install, and can also simultaneously reduce flight resistance, providing favorable conditions for control devices such as vector nozzles that require engine energy injection.

[0031] After verification by wind tunnel experiments and numerical calculations, this embodiment is based on the blade-type vortex generator body 2. When the wing is at a large angle of attack, the nose-up moment can be reduced by about 20%±5% in the case of low-speed flight.

[0032] Wing 1 is half of a tailless flying wing, that is, two wings 1 are symmetrically connected to form a complete tailless flying wing. Figure 4 As shown, the leeward side 14 of the wing 1 is the upper surface, the front end of the wing 1 is the leading edge 11, the part connected to the other wing 1 is the convex profile of the fuselage, which is also the position of the wing root 12, and the rear end of the wing 1 is arranged with a deflection flap, which is also the position of the trailing edge 13. The wing 1 as a whole can be close to a triangle, and the corner where the leading edge 11 and the trailing edge 13 are connected is the wing tip.

[0033] The blade-shaped vortex generator body 2 is used to combine with the raised surface of the wing root 12 to construct a local nozzle-like area near the wall (the surface close to the leeward surface 14). The specific type of the blade-shaped vortex generator body 2 can be set according to actual needs and is not limited to this.

[0034] Unlike conventional wing blade devices, the effect of the wing blade type vortex generator body 2 on improving the outer side pressure distribution is limited under medium-scale geometric dimensions and is not the main source of the control effect of the present embodiment; unlike conventional vortex generators, the wing blade type vortex generator body 2 injects energy into the downstream flow field not by rolling up wingtip vortices at the side edges and thereby transferring energy to the downstream boundary layer, because the main vortex that breaks up at large angles of attack dominates the flow in this area, and therefore, for the wing 1 with the wing blade type vortex generator body 2, it is only necessary to install one on each side of the symmetry plane.

[0035] Figure 2 The wing 1 in the figure is not provided with a wing-shaped vortex generator body 2, which can be obtained from Figure 2 It can be seen that the local flow field on the upper surface of the deflection flap is in a separated state. Figure 3 The wing 1 in the embodiment is provided with a wing-shaped vortex generator body 2, that is, the wing 1 of the present embodiment, which can be Figure 3 It can be seen from the figure that the local flow field on the upper surface of the deflection flap changes from a separated state to an attached state.

[0036] In some embodiments, the blade-type vortex generator body 2 includes: a flat plate, which is arranged on the leeward surface 14 of the wing 1, and the flat plate is arranged close to the leading edge 11. The length of the flat plate along the flow direction of the attached airflow on the leeward surface 14 and the length of the wing root 12 are in a first preset ratio; the height of the flat plate along the normal direction of the leeward surface 14 and the length of the wing root 12 are in a second preset ratio; the spacing between the flat plate and the wing root 12 and the span length of the wing 1 are in a third preset ratio; and the flat plate and the wing root 12 are at a preset angle.

[0037] It can be understood that, since the length of the flat plate along the leeward surface 14 in the direction of the attached airflow and the length of the wing root 12 are in a first preset ratio, the height of the flat plate along the normal direction of the leeward surface 14 and the length of the wing root 12 are in a second preset ratio, the spacing between the flat plate and the wing root 12 and the spanwise length of the wing 1 are in a third preset ratio, and the flat plate and the wing root 12 are at a preset angle, the flat plate can be accurately arranged near the leading edge of the leeward surface 14 of the wing 1, so that when the flying wing is in a large angle of attack state, the flat plate can be combined with the convex surface of the wing root 12 to construct a local nozzle-like area close to the leeward surface 14 between the convex surface of the flat plate and the wing root 12, thereby accelerating the attached airflow on the leeward surface 14, and then changing the local flow field on the deflection flap surface of the trailing edge 13 from a separated state to an attached state.

[0038] It should be noted that the flat plate is arranged on the leeward surface 14 of the wing 1 and is located near the leading edge. The specific type of the flat plate can be set according to actual needs and is not limited to this. For example, the flat plate is a medium-sized plate structure and is arranged along the normal direction of the leeward surface 14.

[0039] The first preset ratio is the ratio between the length of the flat plate along the flow direction of the attached airflow on the leeward surface 14 and the length of the wing root 12. The first preset ratio can be set according to actual needs and is not limited thereto.

[0040] The second preset ratio is the ratio between the height of the flat plate along the normal direction of the leeward surface 14 and the length of the wing root 12. The second preset ratio can be set according to actual needs and is not limited thereto.

[0041] The third preset ratio is the ratio between the distance between the flat plate and the wing root 12 and the span length of the wing 1. The third preset ratio can be set according to actual needs and is not limited thereto.

[0042] The preset angle is the angle between the flat plate and the wing root 12 . The preset angle can be set according to actual needs and there is no limitation on this.

[0043] In some embodiments, the height of the flat plate is greater than the height of the vortex core of the leading edge vortex at the flat plate.

[0044] It can be understood that setting the height of the flat plate greater than the height of the vortex core of the leading edge vortex at the flat plate can ensure that a local nozzle-like area close to the leeward surface 14 is stably and efficiently constructed between the flat plate and the convex surface of the wing root 12, thereby utilizing the accelerated attached airflow to enhance the rudder effect of the flap, thereby achieving the effect of reducing the nose-up moment.

[0045] It should be noted that the height of the flat plate may be slightly greater than the vortex core height of the leading edge vortex at the flat plate. Under the condition that the height is higher than the vortex core height, the pitch moment control effect fluctuates within 5% with the normal height.

[0046] In some embodiments, the spacing between the flat plate and the leading edge 11 is no greater than the height of the flat plate along the normal direction of the leeward surface 14 .

[0047] It can be understood that setting the distance between the flat plate and the leading edge 11 to be no greater than the height of the flat plate along the normal direction of the leeward surface 14 can ensure that a local nozzle-like area close to the leeward surface 14 is stably and efficiently constructed between the flat plate and the convex surface of the wing root 12, thereby utilizing the accelerated attached airflow to enhance the rudder effect of the flap, thereby achieving the effect of reducing the nose-up moment.

[0048] It should be noted that the distance between the flat plate and the leading edge 11 may be close to the height of the flat plate along the normal direction of the leeward surface 14 .

[0049] In some embodiments, a first preset ratio between the length of the flat plate along the leeward surface 14 in the direction of the attached airflow and the length of the wing root 12 is in a range of 1% to 10%.

[0050] It can be understood that setting the first preset ratio range between the length of the flat plate along the flow direction of the attached airflow on the leeward surface 14 and the length of the wing root 12 to be 1%-10% can ensure that a local nozzle-like area close to the leeward surface 14 is stably and efficiently constructed between the convex surface of the flat plate and the wing root 12, thereby utilizing the accelerated attached airflow to enhance the rudder effect of the flap, thereby achieving the effect of reducing the nose-up moment.

[0051] It should be noted that the ratio between the length of the flat plate along the flow direction of the attached airflow on the leeward surface 14 and the length of the wing root 12 can be 1%, 2%, 4%, 5%, 6.3%, 7%, 10%, etc., without limitation. Among them, under the condition of being higher than 1% of the length of the wing root 12, the pitch moment control effect fluctuates within 10% with the length of the flat plate in the flow direction.

[0052] In some embodiments, a second predetermined ratio between the height of the flat plate along the normal direction of the leeward surface 14 and the length of the wing root 12 is in a range of 0.5% to 2%.

[0053] It can be understood that setting the second preset ratio range between the height of the flat plate along the normal direction of the leeward surface 14 and the length of the wing root 12 to 0.5%-2% can ensure that a local nozzle-like area close to the leeward surface 14 is stably and efficiently constructed between the flat plate and the convex surface of the wing root 12, thereby utilizing the accelerated attached airflow to enhance the rudder effect of the flap, thereby achieving the effect of reducing the nose-up moment.

[0054] It should be noted that the ratio between the normal height of the flat plate along the leeward surface 14 and the length of the wing root 12 can be 0.5%, 0.6%, 0.9%, 1%, 1.5%, 1.8%, 2%, etc., and there is no limitation on this.

[0055] In some embodiments, a third predetermined ratio between the spacing between the plate and the wing root 12 and the spanwise length of the wing 1 is 50%.

[0056] It can be understood that setting the third preset ratio between the spacing between the flat plate and the wing root 12 and the span-wise length of the wing 1 to 50% can ensure that a local nozzle-like area close to the leeward side 14 is stably and efficiently constructed between the flat plate and the convex surface of the wing root 12, thereby utilizing the accelerated attached airflow to enhance the rudder effect of the flap, thereby achieving the effect of reducing the nose-up moment.

[0057] It should be noted that, for a tailless flying wing formed by two wings 1 connected symmetrically, the position of the flat plate is equivalent to being located at a quarter of the span length.

[0058] In some embodiments, the preset angle between the flat plate and the wing root 12 is in the range of -10° to 10°.

[0059] It can be understood that setting the preset angle range between the flat plate and the wing root 12 to -10° can ensure that a local nozzle-like area close to the leeward side 14 is stably and efficiently constructed between the flat plate and the convex surface of the wing root 12, thereby utilizing the accelerated attached airflow to enhance the rudder effect of the flap, thereby achieving the effect of reducing the nose-up moment.

[0060] It should be noted that the angle between the flat plate and the wing root 12 can be -10°, -8°, -5°, -3°, 0°, 3°, 6°, 10°, etc., without limitation. The angle between the flat plate and the wing root 12 has a control effect fluctuation of about 9% within the range of -10° to 10°.

[0061] In summary, the blade-type vortex generator according to this embodiment can have the following beneficial effects:

[0062] 1. It can effectively control the flight stability of flying wing layout aircraft at high angles of attack. Specifically, by arranging a medium-sized wing-shaped vortex generator body 2 near the leading edge, the flap rudder effect at high angles of attack is effectively improved, and the nose-up moment at high angles of attack is significantly reduced;

[0063] 2. Compatible with the aerodynamic design of the aircraft. Specifically, while improving the aerodynamic torque, the impact on lift and drag is small and beneficial to flight, and basically does not affect flight performance parameters other than control parameters;

[0064] 3. Compatible with the stealth design of the aircraft. Specifically, the geometric shape and installation location of the added device will not destroy the original stealth design of the aircraft;

[0065] 4. Compatible with the aircraft structural design. Specifically, it meets the feasibility requirements of the structural design, has a simple structure and is easy to process.

[0066] It should be noted that, in the description of the present disclosure, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present disclosure, unless otherwise specified, the meaning of "plurality" is two or more.

[0067] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present disclosure includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present disclosure belong.

[0068] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0069] Although the embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present disclosure. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present disclosure.

Claims

1. A wing-shaped vortex generator for improving the rudder effect of a flying wing at a large angle of attack, characterized in that: The wing of the flying wing comprises: a leading edge, a wing root with a convex profile of the fuselage, and a trailing edge with a deflection flap, wherein the leading edge, the wing root, and the trailing edge are connected in sequence, and the wing blade type vortex generator comprises: A blade-shaped vortex generator body, wherein the blade-shaped vortex generator body is arranged on the leeward side of the wing and is arranged close to the leading edge; Among them, when in a large angle of attack state, the blade-shaped vortex generator body is used to combine with the convex surface of the wing root to construct a local nozzle-like area close to the leeward surface to accelerate the attached airflow on the leeward surface, thereby changing the local flow field on the deflection flap surface of the trailing edge from a separated state to an attached state.

2. The wing-shaped vortex generator for improving the rudder effect of a flying wing at a large angle of attack according to claim 1, characterized in that: The blade-shaped vortex generator body comprises: A flat plate, the flat plate is arranged on the leeward side of the wing, and the flat plate is arranged close to the leading edge; Wherein, the length of the flat plate along the direction of the attached airflow on the leeward surface and the length of the wing root are in a first preset ratio; The height of the flat plate along the normal direction of the leeward surface and the length of the wing root are in a second preset ratio; The spacing between the flat plate and the wing root and the span length of the wing are in a third preset ratio; The flat plate and the wing root form a preset angle.

3. The wing-shaped vortex generator for improving the rudder effect of a flying wing at a large angle of attack according to claim 2, characterized in that: The height of the flat plate is greater than the height of the vortex core of the leading edge vortex at the flat plate.

4. The wing-shaped vortex generator for improving the rudder effect of a flying wing at a large angle of attack according to claim 2, characterized in that: The distance between the flat plate and the leading edge is not greater than the height of the flat plate along the normal direction of the leeward surface.

5. The wing-shaped vortex generator for improving the rudder effect of a flying wing at a large angle of attack according to claim 2, characterized in that: The first preset ratio between the length of the flat plate along the direction of the attached airflow on the leeward surface and the length of the wing root is in the range of 1%-10%.

6. The wing-shaped vortex generator for improving the rudder effect of a flying wing at a large angle of attack according to claim 2, characterized in that: The second preset ratio between the height of the flat plate along the normal direction of the leeward surface and the length of the wing root is in a range of 0.5% to 2%.

7. The wing-shaped vortex generator for improving the rudder effect of a flying wing at a large angle of attack according to claim 2, characterized in that: The third preset ratio between the spacing between the flat plate and the wing root and the span length of the wing is 50%.

8. The wing-shaped vortex generator for improving the rudder effect of a flying wing at a large angle of attack according to claim 2, characterized in that: The preset angle between the flat plate and the wing root is in the range of -10° to 10°.

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