Wing end standing vortex high lift device

Abstract

The invention discloses a wing end standing vortex lift augmentation device which comprises a device upper surface, a device lower surface, a leading edge surface and a wing profile, a wing upper wing surface extends outwards to form the device upper surface, a wing lower wing surface extends outwards to form the device lower surface, and the extension length of the device upper surface is larger than that of the device lower surface. A distance exists between the upper surface and the lower surface of the device, and wingtips do not coincide with each other; the device upper surface, the device lower surface, the front edge surface and the airfoil profile jointly form a semi-closed cavity, when incoming flow exists in the semi-closed cavity, a wing end standing vortex rotating in the direction away from the central axis of the fuselage is formed in the semi-closed cavity, and the rotating direction of the wing end standing vortex is opposite to that of a wingtip vortex. According to the three-dimensional wing, airflow on the lower wing surface of the wing is prevented from flowing to the upper wing surface of the wing through the wing end standing vortex in the semi-closed cavity, so that the trend that the airflow on the lower wing surface of the wing is reversed upwards can be inhibited under the condition of not depending on physical obstruction, the lift force of the three-dimensional wing is effectively increased, and the induced resistance is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of aircraft wings, and in particular to a wing tip trapped vortex lift-increasing device. Background Art

[0002] When the aerodynamic performance of a two-dimensional airfoil is applied to a three-dimensional wing, the lift decreases and the induced drag increases. For wings with a small aspect ratio, the impact is extremely serious. The reason is that the airflow on the lower wing surface at the wing tip will be reflected to the upper wing surface due to the wing tip effect, reducing the pressure difference between the upper and lower wing surfaces. Due to the change in the airflow field, the lift of the wing decreases, and at the same time, the induced drag also increases accordingly, and the lift-to-drag ratio decreases. Theory and practice have proved that the slope of the lift line and the aspect ratio are inversely proportional to each other. The simplified expression of the slope of the lift coefficient is: C L α(3D)=Cα(2D)*R;R=A / (A+2),δR / δA=2 / (A+2) 2 (Where A is the aspect ratio, and R is the lift line slope reduction coefficient). In the design of related aircraft wings, some aircraft have to adopt a small aspect ratio aerodynamic shape in order to obtain good performance in the supersonic flight range. For example, the aspect ratio A of carrier-based aircraft is only about 3, which leads to a reduction of more than 40% in lift in the subsonic range, a significant increase in induced drag, and a very small lift-to-drag ratio, making it extremely difficult for the aircraft to take off from an aircraft carrier in a short distance. The take-off and landing speeds are too high, so take-off and landing can only be achieved through catapults and arresting cables, and the requirements for pilots are extremely strict, posing great safety risks. Even for large civil passenger aircraft with a large aspect ratio, this three-dimensional negative effect will lead to increased fuel consumption, reduced operating economic efficiency, and increased costs.

[0003] For this reason, aviation engineers put a lot of thought into the design of wingtip structures when designing aircraft wings. Since the advent of aircraft more than 100 years ago, aviation scientists around the world have come up with many methods to improve the aerodynamic characteristics of wingtips, and many technologies or devices have emerged. Among them, the more famous design is the concept of winglets first proposed by Whitcomb of the United States in 1976, which increases the effective aspect ratio of the wing, improves lift, reduces drag, and increases the lift-to-drag ratio. For example, Boeing 747-400, Airbus A310-A340 and Soviet Il-96 are all equipped with winglets. The lift-increasing and drag-reducing mechanism of this configuration adopts the physical isolation method, which is similar to the initial wing end partition. However, the wingtip winglet only achieves an improvement in aerodynamic performance of about 3%-8%. If the weight increase and drag increase caused by the installation of the winglet are taken into account, the net benefit will be greatly reduced. Therefore, some aircraft are no longer even equipped with winglets. To date, the wingtip structure design has not been well solved and has become a difficult problem that needs to be solved urgently in the industry. Summary of the invention

[0004] The purpose of the present invention is to provide a wing tip trapped vortex lift-increasing device for increasing lift and reducing drag of a wing, which can solve the problem that the aerodynamic performance of the currently used wing tip winglets is not significantly improved.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] The present invention discloses a wing tip trapped vortex lift-increasing device, comprising an upper surface of the device, a lower surface of the device, a leading edge surface and an airfoil section, wherein the upper wing surface of the wing extends outward to form the upper surface of the device, and the lower wing surface of the wing extends outward to form the lower surface of the device, the span of the upper surface of the device is greater than the span of the lower surface of the device, there is a distance between the upper surface of the device and the lower surface of the device, and the upper surface of the device and the lower surface of the device do not overlap at the wing tip; the upper surface of the device, the lower surface of the device, the leading edge surface and the airfoil section jointly form a semi-enclosed cavity, and the semi-enclosed cavity is When there is incoming flow in the semi-enclosed cavity, a wingtip trapped vortex is formed inside the semi-enclosed cavity, which rotates away from the center axis of the fuselage. The rotation direction of the wingtip trapped vortex is opposite to that of the wingtip vortex, and is used to prevent the airflow on the lower surface of the wing from flowing to the upper surface of the wing.

[0007] In an optional embodiment, during flight, the air pressure inside the semi-enclosed cavity is greater than the air pressure on the upper surface of the wing and the air pressure on the lower surface of the wing, and the air pressure on the upper surface of the wing is lower than the air pressure on the lower surface of the wing.

[0008] In an optional embodiment, the spanwise depth h of the semi-enclosed cavity is the geometric chord C of the airfoil section. t 10%-40% of the length.

[0009] In an optional embodiment, the curvature of the upper surface of the device is the same as the curvature of the upper surface of the wing, and the curvature of the lower surface of the device is the same as the curvature of the lower surface of the wing.

[0010] In an optional embodiment, when observed from the position of the aircraft cabin, the wingtip trapped vortex on the left wing side is in a counterclockwise direction, and the wingtip trapped vortex on the right wing side is in a clockwise direction.

[0011] In an optional embodiment, the wingtip trapped vortex lift-enhancing device is a fixed structure and is fixed to the wingtip.

[0012] In an optional embodiment, the wingtip trapped vortex lift-enhancing device is a retractable structure, which can slide toward the wingtip and be deployed, or be retracted and stored inside the wing.

[0013] According to another aspect of the present invention, there is provided a wing, wherein the wing adopts the wingtip trapped vortex lift-increasing device described in the above aspect.

[0014] According to another aspect of the present invention, an aircraft is provided, wherein the aircraft adopts the wing described in the above aspect.

[0015] Compared with the prior art, the beneficial technical effects of the present invention are:

[0016] The wingtip trapped vortex lift-increasing device of the present invention prevents the airflow on the lower surface of the wing from flowing to the upper surface of the wing by means of the wingtip trapped vortex in a semi-enclosed cavity, thereby suppressing the upward tendency of the airflow on the lower surface of the wing without relying on physical barriers, effectively increasing the lift of the three-dimensional wing and reducing the induced drag. The present invention is suitable for the field of aircraft wing design. For wings with a small aspect ratio, if the wingtip trapped vortex lift-increasing device is installed, the lift-increasing and drag-reducing effects are particularly significant. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 Schematic diagram of the structure of the wing tip trapped vortex lift-enhancing device according to Embodiment 1 of the present invention;

[0019] Figure 2 Schematic diagram of the structure of a wing tip trapped vortex lift-enhancing device according to Embodiment 2 of the present invention;

[0020] Figure 3 This is a simplified diagram for analyzing the lift-enhancing effect of the wing tip trapped vortex lift-enhancing device according to Embodiment 3 of the present invention;

[0021] Figure 4 This is a schematic diagram of a small aspect ratio wing carrier-based fighter aircraft equipped with a ZWTA according to Embodiment 4 of the present invention;

[0022] Figure 5 This is a schematic diagram of a flying car equipped with a ZWTA according to Embodiment 5 of the present invention;

[0023] Figure 6 This is a schematic diagram of a flying motorcycle equipped with a ZWTA according to Embodiment 6 of the present invention;

[0024] Figure 7 This is a schematic diagram of a disc-shaped wing aircraft equipped with a ZWTA according to Example 7 of the present invention.

[0025] Explanation of the reference numerals: 11. upper surface of the device; 12. lower surface of the device; 13. upper wing surface; 14. lower wing surface; 15. leading edge surface; 16. airfoil section; 17. semi-enclosed cavity. DETAILED DESCRIPTION

[0026] Embodiments of the present invention 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 invention, and cannot be understood as limiting the present invention.

[0027] In the description of the present invention, it should be understood that the terms "length", "width", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] It should be noted that in order to simplify the description of the wing tip trapped vortex lift enhancement device, the term "wing tip trapped vortex lift enhancement device" is replaced by "ZWTA" below. ZWTA is the abbreviation of "Z-TYPE WING TIPASSEMBLY", i.e., the Z-shaped wing tip configuration (i.e., the wing tip trapped vortex lift enhancement device of the present invention).

[0030] Example 1

[0031] Please refer to Figure 1 , Figure 1 A schematic structural diagram of a wingtip trapped vortex lift-enhancing device according to an embodiment of the present invention is given, which can be recorded as a 3.5-face semi-enclosed wingtip trapped vortex lift-enhancing device.

[0032] The wing tip trapped vortex lift enhancement device includes an upper surface 11, a lower surface 12, a leading edge surface 15 and an airfoil section 16; in addition, h is the depth of the wing tip trapped vortex lift enhancement device, C t is the geometric chord length of the airfoil section 16 .

[0033] In this embodiment, if Figure 1As shown, the wing tip trapped vortex lift enhancement device is closely connected by a total of 3.5 curved surfaces, namely, the upper surface 11, the lower surface 12, the leading edge surface 15 and the airfoil section 16, to form a semi-enclosed cavity 17. Figure 1 It can be seen that the upper surface 11 of the device extends to the upper wing surface 13 of the wing, and the lower surface 12 of the device extends to the lower wing surface 14 of the wing. the extension of the upper surface 11 of the device is greater than the extension of the lower surface 12 of the device, and there is a distance between the upper surface 11 and the lower surface 12 of the device, and they do not overlap at the wing tip.

[0034] Furthermore, the upper surface 11, the lower surface 12, the leading edge surface 15 and the airfoil section 16 of the device serve as the side of the wing tip trapped vortex lift-enhancing device, forming a semi-enclosed cavity 17. The wing tip trapped vortex lift-enhancing device is used to generate a wing tip trapped vortex through the semi-enclosed cavity 17. The rotation direction of the wing tip trapped vortex is opposite to that of the wing tip vortex (the wing tip vortex is a vortex formed by the upward reverse airflow), and is used to prevent the airflow of the lower wing surface 14 from flowing to the upper wing surface 13. Among them, since the right wing tip trapped vortex shown in the figure rotates clockwise, the airflow of the lower wing surface 14 cannot flow to the upper wing surface 13.

[0035] In summary, in the embodiment of the present invention, the airflow on the lower surface of the wing is prevented from flowing to the upper surface of the wing by the wing tip trapped vortex in the semi-enclosed cavity, thereby achieving "vortex control vortex". Since the rotation direction of the wing tip trapped vortex is opposite to that of the wing tip vortex, the upward trend of the airflow on the lower surface of the wing can be basically suppressed without relying on hardware physical barriers. It is suitable for the field of aircraft wing design. For wings with small aspect ratios, if a wing tip trapped vortex lift-enhancing device is installed, the lift-enhancing and drag-reducing effects are particularly significant.

[0036] Example 2

[0037] Please refer to Figure 2 , Figure 2 A schematic structural diagram of another wingtip trapped vortex lift-enhancing device according to an embodiment of the present invention is given, which can be recorded as a three-sided semi-enclosed wingtip trapped vortex lift-enhancing device.

[0038] Different from the first embodiment, the lower surface 12 of the device in this embodiment is a part of the extension of the lower wing surface 14 of the wing, that is, compared with the 3.5-sided semi-enclosed wing tip trapped vortex lift-enhancing device, the lower surface 12 of the device does not exist. Figure 2 As shown, in the embodiment of the present invention, the wing tip trapped vortex lift-enhancing device includes a device upper surface 11, a leading edge surface 15 and an airfoil section 16, forming a three-surface semi-enclosed wing tip trapped vortex lift-enhancing device. Figure 2 In the figure, h is the depth of the wing tip trapped vortex lift enhancement device under the current structure, C t is the geometric chord length of the airfoil section 16 .

[0039] and Figure 1 compared to, Figure 2There is no device bottom surface 12, and the rest is Figure 1 Similarly, it can be considered that Figure 2 yes Figure 1 A special case of the configuration of the wing tip trapped vortex lift enhancement device. In practice, which wing tip trapped vortex lift enhancement device to use can be determined in combination with optimizing the overall performance.

[0040] The above-mentioned Embodiments 1 and 2 illustrate two possible structures of the wing tip trapped vortex lift-increasing device. The principle and detailed structure of the wing tip trapped vortex lift-increasing device are further illustrated by the following contents:

[0041] For the wingtip trapped vortex lift-enhancing devices of Example 1 and Example 2, when the wingtip trapped vortex lift-enhancing devices are installed on an aircraft, when observed from the position of the aircraft cabin, the wingtip trapped vortex on the left wing side is in a counterclockwise direction, and the wingtip trapped vortex on the right wing side is in a clockwise direction.

[0042] When there is an incoming flow in the semi-enclosed cavity 17, the airflow in the front part of the cavity is partially blocked, causing the flow speed to slow down. According to Bernoulli's principle (pressure and flow velocity are inversely proportional), when the flow velocity of the airflow in the cavity is slower than the flow velocity of the airflow on the lower wing surface 14 of the wing, the air pressure in the semi-enclosed cavity 17 is higher than the pressures on the upper and lower wing surfaces of the wing, that is, when there is an incoming flow in the semi-enclosed cavity 17, the air pressure in the cavity is greater than the air pressure on the upper wing surface and the air pressure on the lower wing surface, and the air pressure on the upper wing surface is lower than the air pressure on the lower wing surface.

[0043] Therefore, the wing tip trapped vortex lift enhancement device forms three pressure areas in the vertical direction, from top to bottom: the air pressure on the upper wing surface (the lowest pressure), the air pressure in the cavity (the highest pressure), and the air pressure on the lower wing surface (the second highest pressure). Among them, the high-pressure airflow in the cavity will flow to the area with lower pressure than it, that is, flow upward or downward.

[0044] However, since the upper part of the semi-enclosed cavity 17 (i.e., the upper surface 11 of the device) is closed, the airflow in the cavity is prevented from flowing upward and can only flow downward. When the aircraft flies forward, a standing vortex vortex rotating away from the fuselage centerline is formed, and its rotation direction is opposite to that of the wingtip vortex, which prevents (or reduces) the negative impact of the airflow on the lower wing surface 14 of the wing flowing upward.

[0045] In addition, the curvature of the upper surface 11 of the device is the same as the curvature of the upper surface 13 of the wing, and the curvature of the lower surface 12 of the device is the same as the curvature of the lower surface 14 of the wing. Therefore, during the production process, the upper surface 13 of the wing can be directly extended to form the upper surface 11 of the device, and the lower surface 14 of the wing can be directly extended to form the lower surface 12 of the device, so as to simplify the production process.

[0046] In this embodiment, from the perspective of whether it can be retracted or not, the structural design of the wing tip trapped vortex lift-enhancing device can be adaptively designed according to different aircraft models.

[0047] For example, when the aircraft is a subsonic or high subsonic aircraft, the wingtip trapped vortex lift-enhancing device is designed as a fixed structure, and the wingtip trapped vortex lift-enhancing device is fixed to the wingtip; or, during the entire flight of the aircraft, all lift surfaces are in a subsonic leading edge state, then the wingtip trapped vortex lift-enhancing device can also be designed as a fixed structure.

[0048] For another example, when the aircraft is a transonic or supersonic aircraft, the wing tip vortex lift-enhancing device is designed to be a retractable structure. When the aircraft takes off and lands, the wing tip vortex lift-enhancing device slides toward the wing tip and unfolds; when the aircraft is in transonic or supersonic flight, the wing tip vortex lift-enhancing device is retracted and stored inside the wing.

[0049] When designing a ZWTA structure, one will encounter the problem of how to choose the spanwise depth h of the cavity. In the preliminary design, h can be selected to be approximately equal to the geometric chord C of the airfoil section 16. t 10%-40% of the length. In practical application, the h parameter should be optimized through experiments so that the wing tip trapped vortex lift enhancement device can achieve the best effect.

[0050] Example 3

[0051] Attached Figure 3 Wind tunnel test data are provided to illustrate the effectiveness of the "vortex-controlling-vortex" approach.

[0052] Figure 3 This is a simplified diagram of the lift effect analysis after the data of a typical low aspect ratio wing section (three-dimensional) in a low-speed wind tunnel was collated after the ZWTA configuration was used. Among them, curves 1 and 3 are the data measured in the wind tunnel test; curve 2 is the data calculated according to the theoretical formula after considering that the wingspan is doubled after the installation of ZWTA, that is, A = 0.72; curve 4 is the lift line slope of the two-dimensional wing section (supercritical airfoil).

[0053] At present, advanced aerodynamic design technology is very advanced. Supercritical two-dimensional airfoil design has achieved excellent wing aerodynamic characteristics. The slope of the two-dimensional lift line exceeds the classical theoretical value of 2π (0.11 / degree). However, due to the influence of the three-dimensional effect, the aerodynamic efficiency is greatly reduced in practical applications. For a wing with the same airfoil section of 16, when the wingspan is A=0.36, the three-dimensional lift coefficient C L Only 17.9% of the two-dimensional lift coefficient is lost, 82.1%; even if the wingspan is doubled, A = 0.72, the three-dimensional lift coefficient C LThere is an increase, but it is only 23.4% of the two-dimensional one, and a loss of 76.6%; after the installation of ZWTA, the aspect ratio A of the aircraft body is still very small (A = 0.36), but the effect is very significant, changing from curve 1 to curve 3, which is 3.3 times the lift coefficient of the configuration without ZWTA, that is, an increase of 2.3 times. It is equivalent to an increase in the effective aspect ratio to 8.2 times the original. However, the increase in the slope of the lift coefficient from curve 1 to curve 3 is not entirely contributed by the ZWTA device, because it includes the gain of 0.0076 obtained by the increase in geometric wingspan. Therefore, in the future, when calculating the lift-enhancing effect obtained by installing ZWTA on different aircraft wings, a rough estimation method is to only calculate the lift increment caused by the wing tip vortex. That is, the concept of equivalent aspect ratio is introduced, and the amplified aspect ratio data is used to estimate the lift line coefficient slope of the new wing.

[0054] It should be noted that the lift increment caused by ZWTA has basically nothing to do with the aspect ratio of the wing, while the basic lift of the wing is closely related to the aspect ratio. Because the trapped vortex generated by ZWTA leads to increased lift, it is only related to the effectiveness of the upward backflow of the wing tip that can be blocked and the local airflow pattern of the wing tip. Of course, the proportion of this part of the increment in the entire lift of the wing is related to the aspect ratio. The smaller the aspect ratio, the greater the proportion. In wings with large aspect ratios, the lift increase ratio of ZWTA is very small. As an approximate estimate, in future applications, if the ZWTA device of the present invention is adopted, when estimating the lift increment, it can be considered that the increase in the slope of the lift line is due to the increase in the effective aspect ratio to 8.2 times the original. After deducting the influence of the increase in geometric span, the amplification factor of the effective aspect ratio is reduced to 6, and then the effective aspect ratio after the installation of ZWTA is calculated, and the effective wingspan is used to calculate the lift of the wing. The scope of application of this estimation method should be limited to aircraft with wings of smaller aspect ratio (A=0.3-6). This estimation method is very useful in preliminary design. Of course, in formal design, real and more accurate aerodynamic data should be obtained through wind tunnel tests or flight tests as the design basis.

[0055] Example 4

[0056] The application of ZWTA technology to a hypothetical small aspect ratio wing carrier-based fighter aircraft. Figure 4 And Table 1, Table 1 gives the basic data of the small aspect ratio wing carrier-based fighter.

[0057] Table 1

[0058]

[0059]

[0060] Analysis: Assuming the runway is 105 meters long, the calculated rolling time is 5 seconds, and the speed reached is V = 42 meters per second. Aspect ratio A = L 2 / S = 15*15 / 73 = 3.08, which is a small aspect ratio wing. Assuming it is a supercritical wing, the lift line slope of the two-dimensional wing section is C L α =0.126, three-dimensional lift coefficient slope C L1 α =0.6063*0.126=0.0764. After adding ZWTA, the effective aspect ratio is about 18.5. The lift coefficient slope increment is about 0.040. The total lift coefficient slope is C L2 α =0.12, C L1 / C L2 =C L1 α / C L2 α=0.636.

[0061] If we consider the aircraft carrier operation regulations: running at 20 knots, obtaining an initial speed of 10 m / s, sailing against the wind, with a wind speed of about 10 m / s, a total initial speed of 20 m / s can be obtained, plus the energy provided by the power unit, a total runway terminal speed of 66 m / s, which cannot meet the take-off speed requirement of 81 m / s. It can be seen that according to the current aircraft design level, the catapult on the aircraft carrier is indispensable.

[0062] If ZWTA is installed on the aircraft, the total lift of the aircraft during takeoff can be increased. As a rough estimate, as long as the effect of ZWTA on the ground speed is estimated, in order to make the aircraft's lift equal to the total lift of the aircraft during takeoff, L = 1 / 2*r*V 2 *C L *S=W0, where r and S are constants, and W0 is also a constant. When changing the lift coefficient or lift-off speed, the relationship between speed and lift coefficient should keep their product unchanged. That is, V 2 1*C L1 =V 2 2*C L2 , The speed is reduced by 17 m / s. After the ZWTA is used, the aircraft can take off from the ship on a 105 m runway without the aid of a catapult.

[0063] Example 5

[0064] ZWTA lift-enhancing technology is used to design a flying car with an ultra-short wingspan. Figure 5 and Table 2.

[0065] Table 2 gives the basic data of the flying car.

[0066] Table 2

[0067]

[0068] Analysis: The flying car of this embodiment is a wing-body integrated (or wingless) ground-to-air amphibious aircraft. The body (fuselage) is similar to that of an ordinary car, with a V-shaped tail installed at the tail and a 200-horsepower turbofan engine installed at the tail. Due to airworthiness restrictions, the span of the flying car cannot be too long. Therefore, a retractable ZWTA is used. When the car is driving on the ground, the left and right winglets of the ZWTA are folded (sliding to the middle), and the vertical tail at the rear can also change its posture to form a back tank, and the propeller is folded (folded). This is the ground driving mode of the flying car. The aerial flight mode is to extend the left and right winglets to form a ZWTA configuration. The V-tail is installed as an aircraft tail assembly. Turn on the propeller. When the aircraft is not in the ZWTA configuration, it has an ultra-short aspect ratio wing with a lift line slope of only 0.022 / degree, which makes it impossible for it to fly. Once in the ZWTA configuration, the lift line slope is 0.0755 / degree, and the lift is increased to 3.4 times the original value, allowing it to take off horizontally, with a ground speed of 100-150 km / h, a flight altitude of 3,000 meters, a flight speed of 300 km / h, and a range of more than 1,000 km.

[0069] Example 6

[0070] ZWTA lift-enhancing technology is used to design ultra-short wingspan flying motorcycles. Please refer to the attached Figure 6 .

[0071] The flying motorcycle can be regarded as a miniaturized flying car, with the driver outside the wing. The motorcycle body is narrowed, 60 cm wide and 2 meters long, and the body adopts the QYX-5 profile shape. Similar to the flying car, the ZWTA is not installed when driving on the ground. Even if a horizontal tail assembly with a certain wingspan is installed, the total width will not exceed 2.5 meters (the width of a lane). The rear tail assembly is a normal tail, and a canopy wing lift device is installed when necessary. The two ends of the tail horizontal stabilizer are also designed to be ZWTA configurations to further increase the lift. Although the area of ​​the body is small, the main lift is insufficient, but after installing ZWTA on the body and the horizontal stabilizer, the comprehensive total lift is sufficient. The total weight of the motorcycle is 115 kg, which is an ultralight aircraft. The ground take-off speed is 50-80 km / h, the air flight speed can reach 260-300 km / h, and the range exceeds 800 kilometers.

[0072] Example 7

[0073] ZWTA lift-enhancing technology is used in the design of disc-shaped wing aircraft, see Figure 7 .

[0074] This is a special aircraft with a very different appearance from existing aircraft. The top view is a disc, with no distinction between the fuselage and the wing, and the wing and body are integrated. The circular wing has its special properties, good stability, and is not easy to stall at a large angle of attack. It has a closed thin shell structure, no cantilever beams, and a reasonable stress state. It has a large volume space. There are many advantages. However, its aerodynamic shape has a fatal weakness: the aspect ratio is too small and the aerodynamic efficiency is very low. People have found many ways to try to solve this problem and put it into use. For example: install a propeller engine on each side of the disc wing. Make the left and right blades rotate in opposite directions. Others have tried to use the winglet method to prevent the airflow from the lower wing from flowing back to the upper wing, but the results are not ideal. We can use ZWTA to apply to disc-shaped disc-shaped wing aircraft to improve its aerodynamic efficiency, so that it can fly normally and has good flight performance.

[0075] First, let's look at the aerodynamic geometry parameters of the circular wing and set the disk diameter D. At the same time, select a suitable airfoil similar to the Liebeck airfoil with large thickness, high lift-to-drag ratio, and large lift to construct a larger effective space. Along the span of the disk, the dimensionless airfoil is exactly the same from inside to outside. A ZWTA configuration is constructed at 1 / 16D-1 / 8D on the left and right sides, which is 1 / 16D-1 / 8D away from the farthest point of the outer circle. By preventing the airflow on the lower wing surfaces on both sides from flowing back from the bottom to the upper wing surface, the purpose of increasing lift and reducing induced drag is achieved. The flight performance of the aircraft can be greatly improved. Use the method of adding a V-shaped tail to the rear of the aircraft (a normal tail assembly can also be used). Achieve the purpose of control. For example, take a diameter of D = 8 meters. Its wing area is S = / 4*D 2 =50.2656m 2 , the wingspan or diameter D = 8 meters; so the aspect ratio is A = D 2 / S=1.2732, which is an ultra-short aspect ratio wing aircraft.

[0076] The three-dimensional aerodynamic efficiency coefficient of the wing is R = 38.9%. The lift loss is 61.1%. The slope of the two-dimensional lift line of the supercritical airfoil is C L α = 0.126. Based on this, it can be estimated that the slope of the three-dimensional lift coefficient of the disc wing is C L α = 0.04901. Assume that the zero lift angle is -7.8 degrees. At takeoff, the angle of attack is 16 degrees and the lift coefficient is 1.1664. The disc wing area is 50.2 square meters. C L*S=58.5533. When the takeoff speed is 200 km / h, the lift is 11097 kg. Below this speed, the flying saucer with a total weight of 11 tons cannot take off. At this time, the takeoff runway must be at least 3846 meters. If ZWTA is installed, a 0.05 lift line slope increment can be obtained. Therefore, at the same takeoff angle of attack, the maximum lift coefficient is 2.24, almost twice the original. It can be estimated that when the takeoff speed is 150 km / h, the lift reaches 11960 kg, which is enough to make the aircraft with a total weight of 11 tons take off. The speed at this time is 41.6667 meters / second. The runway distance is 2163 meters. If the composite lift-increasing technology is adopted, including blowing air at 70% of the aerodynamic chord of the wing trailing edge, the separation point of the airflow trailing edge is moved backward (it does not increase lift much, but reduces induced drag and increases the lift-to-drag ratio by about 70%). The combined effect can increase the lift coefficient to more than 3.8. Further reduce the takeoff speed and the taxiing distance, and ordinary small airports can take off. The runway is not shorter than 1,200 meters. The total lift-to-drag ratio (cruise) can reach more than 20. Assuming the cruising speed is 650 kilometers per hour, the fuel consumption rate is 0.55. In addition to the structural characteristics of the disc wing This can save weight and load more fuel, so that the fuel efficiency can reach about 0.8. Therefore, the cruising range can reach: L = (650*20 / 0.55)*0.8 = 18,909 kilometers, catching up with the performance of the US Global Hawk UAV. But there is one performance that exceeds the Global Hawk: in the same area as a Global Hawk, about ten disc-shaped wing aircraft can be placed. In addition, the special shape and circular top (bottom) view are conducive to the installation of phased array radar (early warning or command), becoming a large radar antenna that can fly autonomously.

[0077] The present invention discloses a wing provided with a wingtip trapped vortex lift-increasing device, and an aircraft having the wing. The above-mentioned subjects are all within the protection scope of the present invention, including an airplane equipped with the wing, a flying car equipped with the wing, a flying motorcycle, a disc-shaped wing aircraft, etc.

[0078] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A wing tip trapped vortex lift-enhancing device, characterized in that: The invention comprises an upper surface (11), a lower surface (12), a leading edge surface (15) and an airfoil section (16); the upper wing surface (13) of the wing extends outward to form the upper surface (11) of the device; the lower wing surface (14) of the wing extends outward to form the lower surface (12) of the device; the span of the upper surface (11) of the device is greater than the span of the lower surface (12); there is a distance between the upper surface (11) of the device and the lower surface (12) of the device, and the upper surface (11) of the device and the lower surface (12) of the device do not overlap at the wing tip; the upper surface (11), the lower surface (12), the leading edge surface (15) and the airfoil section (16) together form a semi-enclosed cavity (17); the semi-enclosed cavity (17) is The semi-enclosed cavity (17) is shaped such that when there is incoming flow, a wing tip trapped vortex is formed inside the semi-enclosed cavity (17) and rotates away from the center axis of the fuselage. The rotation direction of the wing tip trapped vortex is opposite to that of the wing tip vortex, and is used to prevent the airflow on the lower wing surface (14) from flowing toward the upper wing surface (13).

2. The wing tip trapped vortex lift-increasing device according to claim 1, characterized in that: During flight, the air pressure inside the semi-enclosed cavity (17) is greater than the air pressure on the upper wing surface (13) and the air pressure on the lower wing surface (14), and the air pressure on the upper wing surface (13) is lower than the air pressure on the lower wing surface (14).

3. The wing tip trapped vortex lift-increasing device according to claim 1, characterized in that: The spanwise depth h of the semi-enclosed cavity (17) is equal to the geometric chord C of the airfoil section (16). t 10%-40% of the length.

4. The wing tip trapped vortex lift-increasing device according to claim 1, characterized in that: The curvature of the upper surface (11) of the device is the same as the curvature of the upper wing surface (13) of the wing, and the curvature of the lower surface (12) of the device is the same as the curvature of the lower wing surface (14) of the wing.

5. The wing tip trapped vortex lift-increasing device according to claim 1, characterized in that: Observing from the position of the aircraft cockpit, the wingtip trapped vortex on the left wing side is in a counterclockwise direction, and the wingtip trapped vortex on the right wing side is in a clockwise direction.

6. The wing tip trapped vortex lift-enhancing device according to any one of claims 1 to 5, characterized in that: The wing tip trapped vortex lift-enhancing device is a fixed structure and is fixed to the wing tip.

7. The wing tip trapped vortex lift-enhancing device according to any one of claims 1 to 5, characterized in that: The wing tip trapped vortex lift-enhancing device is a retractable structure, which can slide toward the wing tip and be unfolded or be retracted and stored inside the wing.

8. A wing, characterized in that: The wing tip of the wing is provided with a wing tip trapped vortex lift-increasing device as described in any one of claims 1 to 7.

9. An aircraft, characterized in that: The aircraft has a wing as claimed in claim 8.

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