A winglet vortex generator for improving the effectiveness of a flying wing rudder at high angles of attack

Abstract

The present disclosure provides a wing-sail type vortex generator for improving the rudder effect of a flying wing at a large attack angle, the wing of the flying wing comprising a leading edge, a wing root arranged with a body protruding surface, and a trailing edge arranged with a deflected flap, the leading edge, the wing root and the trailing edge being sequentially connected, the wing-sail type vortex generator comprising a wing-sail type vortex generator body, the wing-sail type vortex generator body being arranged on the leeward surface of the wing and close to the leading edge; wherein when at a large attack angle, the wing-sail type vortex generator body is used to combine with the protruding surface of the wing root to form a local area of a close-to-leeward surface partial nozzle, so that the local flow field of the deflected flap surface of the trailing edge changes from a separation state to an attached state. In the wing-sail type vortex generator for improving the rudder effect of a flying wing at a large attack angle, the arrangement of the wing-sail type vortex generator body on the wing can effectively improve the rudder effect of the flap and achieve the effect of reducing the lifting moment.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of aircraft technology, and in particular to a wing-slit vortex generator for improving the control surface effect of a flying wing at high angles of attack. BACKGROUND

[0002] When a tailless flying wing aircraft makes a high angle of attack maneuver, the leading edge vortex of the vortex lift generated by the flow will usually break early, 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, and the lift-drag and pitch moment enter the nonlinear section with the change of the angle of attack; the control device such as the elevator and the flap reduces the control surface effect, making it difficult to suppress the aircraft's tendency to lift its head, and the longitudinal stability of the aircraft is difficult to control.

[0003] For control problems at high angles of attack, there are generally two solutions: one is to use engine vectoring nozzles for direct control, and to directly adjust the aerodynamic performance by adjusting the thrust direction; the second is to control the separated flow field and vortex, and to 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 there are difficulties in practical application: the difficulties of vectoring nozzles include control accuracy, response delay, and thrust loss; the difficulties of active control methods such as blowing and suction, ionization control include complex structure, large energy demand, and engine air intake limitation; passive control methods such as the use of V-tail, Guney wing and other control devices can achieve good control effect, but such large-scale components will damage the stealth effect of the fuselage, which is contrary to the original design of the aircraft. SUMMARY

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

[0006] To this end, the purpose of the present disclosure is to provide a wing-slit vortex generator for improving the control surface effect of a flying wing at high angles of attack.

[0007] To achieve the above object, the present disclosure provides a wing-slit vortex generator for improving the effectiveness of a flying wing at a large attack angle, the wing of the flying wing comprising a leading edge, a wing root arranged with a body bulge profile, and a trailing edge arranged with a deflected flap, the leading edge, the wing root and the trailing edge being connected in sequence, the wing-slit vortex generator comprising a wing-slit vortex generator body, the wing-slit vortex generator body being arranged on the leeward surface of the wing and close to the leading edge; wherein, when at a large attack angle, the wing-slit vortex generator body is used to jointly form a local nozzle region close to the leeward surface with the bulge profile of the wing root, so as to accelerate the flow of the leeward surface, and further change the local flow field of the deflected flap surface of the trailing edge from a separation state to an attached state.

[0008] Optionally, the wing-slit vortex generator body comprises a flat plate, the flat plate being arranged on the leeward surface of the wing and close to the leading edge; wherein, the length of the flat plate along the flow direction of 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 distance between the flat plate and the wing root and the span length of the wing are in a third preset ratio; and the flat plate and the wing root form a preset included angle.

[0009] Optionally, the height of the flat plate is greater than the vortex core height 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 flow direction of the leeward surface and the length of the wing root ranges from 1% to 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 ranges from 0.5% to 2%.

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

[0014] Optionally, the preset included angle between the flat plate and the wing root ranges from -10° to 10°.

[0015] The technical solution provided by the present disclosure can include the following beneficial effects:

[0016] The winglet vortex generator body is arranged on the leeward surface of the wing, and is arranged close to the leading edge, so that when the flying wing is in a large attack angle state, the winglet vortex generator body can combine with the convex surface of the wing root to form a local close-to-leeward surface nozzle area between the winglet vortex generator body and the convex surface of the wing root, thereby accelerating the flow on the leeward surface, and changing the local flow field of the deflected flap surface of the trailing edge from a separation state to an attached state. Therefore, by arranging the winglet vortex generator body on the wing, the steering effect of the flap can be effectively improved, the lifting moment can be reduced, and the passive geometric shape improvement on the leeward surface of the wing can improve the flight stability, is compatible with the stealth design of the aircraft, and has low processing difficulty.

[0017] Additional aspects and advantages of the present disclosure will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

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

[0019] Figure 1 is a structural schematic diagram of a winglet vortex generator for improving the steering effect of a flying wing in a large attack angle state according to an embodiment of the present disclosure;

[0020] Figure 2 is a structural schematic diagram of a winglet vortex generator for improving the steering effect of a flying wing in a large attack angle state according to an embodiment of the present disclosure (airflow distribution when the winglet vortex generator body is not arranged);

[0021] Figure 3 is a structural schematic diagram of a winglet vortex generator for improving the steering effect of a flying wing in a large attack angle state according to an embodiment of the present disclosure (airflow distribution when the winglet vortex generator body is arranged);

[0022] Figure 4 is a structural schematic diagram of a flying wing according to 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 surface,

[0024] 2, winglet vortex generator body. DETAILED DESCRIPTION

[0025] Embodiments of the present disclosure are described below in detail with reference to examples shown in the drawings, wherein the same or similar notations are used to denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary only, and are for the purpose of explanation only, and are not to be taken as limiting of the present disclosure. On the contrary, the embodiments of the present disclosure encompass all changes, modifications and equivalents that fall within the spirit and scope of the appended claims.

[0026] As shown in Figure 1 The present embodiment proposes a wing-sail type vortex generator for improving the rudder effect of a flying wing in a high angle of attack state. The wing of the flying wing 1 comprises a leading edge 11, a wing root 12 arranged with a body protruding surface, and a trailing edge 13 arranged with a deflected flap. The leading edge 11, the wing root 12 and the trailing edge 13 are sequentially connected. The wing-sail type vortex generator comprises a wing-sail type vortex generator body 2. The wing-sail type vortex generator body 2 is arranged on the leeward surface 14 of the wing 1 and is arranged close to the leading edge 11. When in the high angle of attack state, the wing-sail type vortex generator body 2 is used to combine with the protruding surface of the wing root 12 to form a local nozzle region close to the leeward surface 14, so as to accelerate the body airflow of the leeward surface 14, and further change the local flow field of the deflected flap surface of the trailing edge 13 from a separation state to a body state.

[0027] It can be understood that, since the wing-sail type vortex generator body 2 is arranged on the leeward surface 14 of the wing 1 and is arranged close to the leading edge 11, when the flying wing is in the high angle of attack state, the wing-sail type vortex generator body 2 can combine with the protruding surface of the wing root 12 to form a local nozzle region close to the leeward surface 14 between the wing-sail type vortex generator body 2 and the protruding surface of the wing root 12, so as to accelerate the body airflow of the leeward surface 14, and further change the local flow field of the deflected flap surface of the trailing edge 13 from a separation state to a body state.

[0028] Thus, by arranging the wing-sail type vortex generator body 2 on the wing 1, the rudder effect of the flap can be effectively improved, the lifting moment can be reduced, and the passive geometric shape improvement on the leeward surface 14 of the wing 1 can improve the flight stability while being compatible with the stealth design of the aircraft, and has a low processing difficulty.

[0029] It should be noted that the wing-sail type vortex generator body 2 arranged near the leading edge injects energy into the boundary layer of the downstream flow field, changes the local flow field of the upper surface of the deflected flap from a separation state to a body state, thereby improving the rudder effect to achieve control effect. Specifically, the wing-sail type vortex generator body 2 not only limits the spanwise flow of the leading edge part to produce an acceleration effect, but also forms a new flow direction vortex on the outside to improve the pressure distribution on the outside.

[0030] The wing-sail vortex generator body 2 can not only improve the effectiveness of the flap, but also reduce the drag, and can be compatible with the stealth design and structure design, and is easy to process and install.

[0031] Through wind tunnel experiment and numerical calculation verification, the wing-sail vortex generator body 2 can reduce the lift moment by about 20%±5% in the case of low-speed flight when the flying wing is in a large attack angle state.

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

[0033] The wing-sail vortex generator body 2 is used in combination with the convex surface of the wing root 12 to form a local nozzle area close to the wall surface (the surface close to the leeward surface 14), and the specific type of the wing-sail vortex generator body 2 can be set according to actual needs, which is not limited.

[0034] Unlike conventional wing-sail devices, the improvement effect of the wing-sail vortex generator body 2 on the outside pressure distribution is limited in the case of medium-scale geometry, which is not the main control effect source of the present embodiment; unlike conventional vortex generators, the wing-sail vortex generator body 2 injects energy into the downstream flow field, which is not through rolling up the wing tip vortex at the side edge to transfer energy to the downstream boundary layer, because the main vortex broken at a large attack angle dominates the flow in this area, and therefore for the wing 1 of the wing-sail vortex generator body 2, only one is needed on each side of the symmetry plane.

[0035] Figure 2 The wing 1 in Figure 2 It can be seen from Figure 3 The wing 1 in Figure 3 It can be seen from

[0036] In some embodiments, the winglet vortex generator body 2 comprises a flat plate arranged on the leeward surface 14 of the wing 1 and close to the leading edge 11. The length of the flat plate along the flow direction of the body surface flow 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 distance 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 form a preset included angle.

[0037] It can be understood that, due to the first preset ratio between the length of the flat plate along the flow direction of the body surface flow on the leeward surface 14 and the length of the wing root 12, the second preset 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 third preset ratio between the distance between the flat plate and the wing root 12 and the span length of the wing 1, and the preset included angle between the flat plate and the wing root 12, 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 jointly form a local nozzle region close to the leeward surface 14 between the flat plate and the convex surface of the wing root 12, thereby accelerating the body surface flow on the leeward surface 14, and further changing the local flow field of the deflected flap surface of the trailing edge 13 from a separation 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 close to the leading edge, and the specific type of the flat plate can be set according to actual needs, which is not limited herein. For example, the flat plate is a medium-scale plate structure, and the flat plate 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 body surface flow on the leeward surface 14 and the length of the wing root 12, which can be set according to actual needs, which is not limited herein.

[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, which can be set according to actual needs, which is not limited herein.

[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, which can be set according to actual needs, which is not limited herein.

[0042] The preset included angle is the included angle between the flat plate and the wing root 12, which can be set according to actual needs, which is not limited herein.

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

[0044] It can be understood that the height of the flat plate is greater than the vortex core height of the leading edge vortex at the flat plate, which can ensure that the local nozzle region close to the leeward surface 14 is stably and efficiently constructed between the flat plate and the convex surface of the wing root 12, so as to improve the rudder effect of the flap by using the accelerated body airflow, and then realize the function of reducing the lifting moment.

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

[0046] In some embodiments, the distance between the flat plate and the leading edge 11 is not greater than the height of the flat plate normal to the leeward surface 14.

[0047] It can be understood that the distance between the flat plate and the leading edge 11 is not greater than the height of the flat plate normal to the leeward surface 14, which can ensure that the local nozzle region close to the leeward surface 14 is stably and efficiently constructed between the flat plate and the convex surface of the wing root 12, so as to improve the rudder effect of the flap by using the accelerated body airflow, and then realize the function of reducing the lifting moment.

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

[0049] In some embodiments, the first preset proportion range between the length of the flat plate along the flow direction of the body airflow on the leeward surface 14 and the length of the wing root 12 is 1%-10%.

[0050] It can be understood that the first preset proportion range between the length of the flat plate along the flow direction of the body airflow on the leeward surface 14 and the length of the wing root 12 is 1%-10%, which can ensure that the local nozzle region close to the leeward surface 14 is stably and efficiently constructed between the flat plate and the convex surface of the wing root 12, so as to improve the rudder effect of the flap by using the accelerated body airflow, and then realize the function of reducing the lifting moment.

[0051] It should be noted that the proportion between the length of the flat plate along the flow direction of the body 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., which is not limited. Under the condition of being higher than 1% of the length of the wing root 12, the floating of the pitch moment control effect with the length of the flat plate flow direction is within 10%.

[0052] In some embodiments, the second preset proportion range between the height of the flat plate normal to the leeward surface 14 and the length of the wing root 12 is 0.5%-2%.

[0053] It can be understood that the second preset proportion range between the height of the plate along the normal direction of the leeward surface 14 and the length of the wing root 12 is 0.5%-2%, which can ensure that the local nozzle region close to the leeward surface 14 is stably and efficiently constructed between the plate and the convex surface of the wing root 12, so as to improve the rudder effect of the flap by using the accelerated body airflow, and then realize the function of reducing the lifting moment.

[0054] It should be noted that the proportion between the height of the plate along the normal direction of 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., which is not limited.

[0055] In some embodiments, the third preset proportion between the distance between the plate and the wing root 12 and the span length of the wing 1 is 50%.

[0056] It can be understood that the third preset proportion between the distance between the plate and the wing root 12 and the span length of the wing 1 is 50%, which can ensure that the local nozzle region close to the leeward surface 14 is stably and efficiently constructed between the plate and the convex surface of the wing root 12, so as to improve the rudder effect of the flap by using the accelerated body airflow, and then realize the function of reducing the lifting moment.

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

[0058] In some embodiments, the preset included angle between the plate and the wing root 12 ranges from -10° to 10°.

[0059] It can be understood that the preset included angle between the plate and the wing root 12 ranges from -10° to 10°, which can ensure that the local nozzle region close to the leeward surface 14 is stably and efficiently constructed between the plate and the convex surface of the wing root 12, so as to improve the rudder effect of the flap by using the accelerated body airflow, and then realize the function of reducing the lifting moment.

[0060] It should be noted that the included angle between the plate and the wing root 12 can be -10°, -8°, -5°, -3°, 0°, 3°, 6°, 10°, etc., which is not limited. Among them, the included angle between the plate and the wing root 12 in the range of -10° to 10° will have about 9% of the control effect floating.

[0061] In summary, the wing knife type vortex generator based on the present embodiment can include the following beneficial effects:

[0062] 1. The wing flying layout aircraft can effectively control the flight stability at large attack angle. Specifically, by arranging the medium scale wing knife vortex generator body 2 near the leading edge, the flap rudder effect at large attack angle is effectively improved, and the lifting moment at large attack angle is significantly reduced.

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

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

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

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

[0067] Any process or method descriptions in flow charts or otherwise described herein, represent embodiments which can be understood as a sequence of steps of executable instructions for computing devices or processing means associated with performing specific logic functions or steps in the processes, and the scope of embodiments of the present disclosure includes additional implementations that can not be precisely shown or described in the figures or otherwise described herein, including implementations involving the performance of one or more steps in a different order, including substantially concurrently, and / or implementations involving the performance of one or more steps in reverse order, and / or involving the performance of one or more steps in an alternative manner, as will be understood by persons skilled in the art of the embodiments described herein.

[0068] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like 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 the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can 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 can be understood that the above embodiments are exemplary and cannot be understood as limiting the present disclosure, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present disclosure.

Claims

1. A winglet vortex generator for improving the effectiveness of a flying wing rudder at high angles of attack, the winglet vortex generator comprising: The wing of the flying wing includes a leading edge, a wing root arranged with a convex surface of the fuselage, and a trailing edge arranged with a deflected flap, the leading edge, the wing root and the trailing edge being connected in sequence, and the wing-slat vortex generator includes: a wing-slat vortex generator body arranged on the leeward surface of the wing and close to the leading edge; wherein, when in a large angle of attack state, the wing-slat vortex generator body is used to combine with the convex surface of the wing root to form a local nozzle area close to the leeward surface, so as to accelerate the flow of the leeside surface, and then change the local flow field of the deflected flap surface of the trailing edge from separation state to attachment state. The wing-slat vortex generator body includes a flat plate arranged on the leeward surface of the wing and close to the leading edge; wherein the length of the flat plate along the flow direction of 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 distance between the flat plate and the wing root and the span length of the wing are in a third preset ratio, and the flat plate and the wing root are at a preset angle. The height of the flat plate is greater than the vortex core height of the leading edge vortex at the flat plate. 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.

2. The winglet vortex generator of claim 1, wherein, The first preset ratio between the length of the flat plate along the flow direction of the leeward surface and the length of the wing root ranges from 1% to 10%.

3. The winglet vortex generator of claim 1, wherein, 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 ranges from 0.5% to 2%.

4. The winglet vortex generator of claim 1, wherein, The third preset ratio between the distance between the flat plate and the wing root and the span length of the wing is 50%.

5. The winglet vortex generator of claim 1, wherein, The preset angle between the flat plate and the wing root ranges from -10° to 10°.

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