A full-slot flap lift-increasing and drag-reducing system and construction method thereof

Abstract

The present invention provides a full-slot flap lift-increasing and drag-reducing system and a construction method thereof. The system is arranged on both sides of an aircraft fuselage, and includes a basic wing and a full-slot flap. The basic wing adopts a laminar airfoil with a relatively large thickness. The full-slot flap is arranged above the basic wing, close to the upper wing surface of the basic wing, and has a gap between the upper wing surface; the span direction of the full-slot flap covers the entire span length of the upper wing surface, and the curvature of the full-slot flap is the same as the curvature of the upper wing surface. The present invention comprehensively considers the lift-increasing and drag-reducing schemes of the wing, develops and designs drag-reducing equipment while constructing the lift-increasing system, and optimizes lift and drag at the same time, thereby obtaining a large lift-to-drag ratio, improving flight efficiency, and being conducive to saving energy (fuel or electricity), so that the aircraft can fly faster and farther, and stay in the air longer; making the taxiing distance shorter, saving a large amount of land resources, and achieving energy saving, emission reduction, low carbon, and green travel; and the structure is simple and reasonable, the cost is low, and it is conducive to popularization and application.

Description

Technical Field

[0001] The present invention relates to the field of aviation engineering technology, in particular, to the field of lift-increasing and drag-reducing technology; specifically, to a full-slotted flap lift-increasing and drag-reducing system and a construction method thereof. Background Art

[0002] Research on lift-enhancing technology has always been a hot topic in the aviation field. The purpose of research on lift-enhancing technology mainly includes two aspects: one is to increase the aircraft's payload, that is, to be able to carry more people or cargo; the second is to shorten the takeoff distance.

[0003] At present, many lift-enhancing devices have been developed, mainly various types of flaps or slats. Among them, the retreating flap, also known as the Fuller flap, is the most effective way to increase lift. The lift coefficient of the wing is increased by temporarily increasing the wing area and / or increasing the curvature of the wing section. Boeing has developed 1 to 6 Fuller flaps in series, which can increase the lift coefficient of the wing to more than 4-5.

[0004] However, too many tandem receding flaps will make the structure too complicated and increase the cost. At the same time, it will also increase the total weight of the aircraft and reduce the flight performance. Therefore, common aircraft usually only use a single Fuller flap, and add leading edge slats when necessary. So far, after installing the high-lift system, various aircraft can obtain a maximum lift coefficient of 2-3, which can meet the needs under normal circumstances.

[0005] However, in some special cases, a higher lift coefficient is required, and conventional flaps alone can no longer meet the demand. For example, the takeoff run distance of a normal aircraft at an ordinary airport is about 1,000 meters to 2,000 meters, while a long-range large passenger aircraft requires a runway of more than 3,000 meters. If the same type of aircraft needs to take off and land at a plateau airport, it is usually impossible to have a runway of the above length. For this reason, it is necessary to develop new lift-enhancing systems, such as adding wing strips, adsorbing or blowing off the turbulent boundary layer on the wing surface, etc. However, these lift-enhancing technologies are very complicated to implement.

[0006] The applicant's patent CN02133862.0 "A canopy wing for increasing lift and stall angle of attack" more than 20 years ago was applied to small drones, with good lift-increasing effects. Aircraft designers at home and abroad have tried to apply this patented technology to design large transport aircraft, such as the Y-8 aircraft independently developed by my country, and the "Boeing Pelican" super-large and giant military transport aircraft (take-off weight exceeding 1,200 tons) that the Boeing Aircraft Company of the United States has started to develop, but they did not get the expected results. In short, the application value of the patent CN02133862.0 for large aircraft is not ideal, and the patent implementation effect is slightly poor.

[0007] After years of analysis and research, the applicant found that there was nothing wrong with the technical idea of ​​patent CN02133862.0. It uses relatively simple processes and materials. When the aircraft takes off or lands, a "canopy wing" with the same curvature as the original wing is placed above the upper wing surface of the original wing to change the pressure distribution on the upper surface of the wing. After verification by wind tunnel blowing, it has achieved a lift-enhancing effect of about 80%, which is equivalent to the combined lift-enhancing effect of Fuller flaps plus leading edge slats. If lift-enhancing is not needed during horizontal cruising flight, the canopy wing is folded up to make the canopy wing close to the upper wing surface of the original wing, and the aerodynamic characteristics are consistent with the original airfoil. The problems mainly lie in the following two aspects:

[0008] (1) The wide adaptability of structural materials during implementation was not fully considered;

[0009] (2) The purpose of increasing the lift of the wing and its impact on the overall situation, especially the negative impact, were not comprehensively considered and no corresponding measures were taken.

[0010] Through fluid dynamics CFD simulation, it was found that when the canopy wing was opened, the pressure on the base wing structure and the canopy wing structure was unexpected. It was originally believed that the base wing should bear the main aerodynamic load, and the canopy wing should only bear a small part of the load. The calculation results are shown in Figure 1 As shown. However, it is now found that when the canopy wing is opened, the aerodynamic load acting on the canopy wing piece is almost the same as the load on the basic wing in size and distribution, and the aerodynamic load on the canopy wing piece is even slightly greater than the aerodynamic load on the basic wing. This phenomenon does not show obvious differences when applied to small drones, and there have been no problems with structural stiffness and strength. However, if this form of structure is applied to large or super-large aircraft, it will not be able to withstand a load equivalent to half the weight of the entire aircraft if structural reinforcement measures are not taken on the thin shell structure of the canopy wing. Therefore, all large-sized aircraft, especially manned aircraft, need to use materials with sufficient strength and stiffness to make thin wings with thickness and airfoil to serve as the upper wing surface of the full-slotted flap; routine tests of structural strength, stiffness and fatigue strength must be carried out during the manufacturing process.

[0011] It was also found that the lift-to-drag ratio decreased while the lift increased. Figure 2 As shown in the figure, the data in the first row are the data of the basic wing without the lift-enhancing device installed. The lift-to-drag ratio of the basic wing is 7.5 (thin airfoil). Figure 2 The lift-to-drag ratio K in the 7th column on the figure shows that as long as the flaps are installed, the lift-to-drag ratio K always decreases. Moreover, the better the lift-increasing effect, the more the lift-to-drag ratio decreases. The minimum is reduced to 3, which is only 60% of the original basic wing, and the lift-to-drag ratio is lost by half. The decrease in lift-to-drag ratio means a decrease in flight efficiency. Reducing the lift-to-drag ratio to improve the lift-increasing effect is too costly to increase lift, and the loss outweighs the gain. Summary of the invention

[0012] In view of this, the purpose of the present invention is to propose a full-slotted flap lift-increasing and drag-reducing system and a construction method thereof, comprehensively consider the lift-increasing and drag-reducing schemes of the wing, solve the problem of a decrease in lift-to-drag ratio caused by lift-increasing from a global and overall perspective, and simultaneously develop and design the drag-reducing equipment of the wing when constructing the lift-increasing system, so that the lift as the numerator is increased and the drag as the denominator is reduced, and the lift and drag are optimized at the same time to obtain a large lift-to-drag ratio, improve flight efficiency, and help save energy (fuel or electricity), so that the aircraft can fly faster and farther and stay in the air longer; shorten the taxiing distance, save land resources, and achieve energy saving, emission reduction, low carbon, and green travel.

[0013] The present invention provides a full-slot flap lift-increasing and drag-reducing system, which is arranged on both sides of an aircraft fuselage and comprises: a basic wing and a full-slot flap (canopy wing). The basic wing adopts a relative thickness (relative thickness t / c refers to the length of a straight line segment between the upper and lower surfaces of the airfoil perpendicular to the chord, and the maximum thickness t of the airfoil is max The laminar flow airfoil has a large ratio of the length of the base wing to the chord length c, the full-slotted flap is arranged above the basic wing, close to the upper wing surface of the basic wing, and has a gap between the full-slotted flap and the upper wing surface; the full-slotted flap covers the entire span length of the upper wing surface in the span direction, and the curvature of the full-slotted flap is the same as the curvature of the upper wing surface; the full-slotted flap is a thin wing with an airfoil section and a small thickness, which is made of a light specific gravity, high strength and high rigidity material.

[0014] The lift-enhancing effect of the full-slot flap (canopy wing) does not exist in isolation, but is related to other dynamic principles of the aircraft. Figure 2 As shown in the results given in , the greater the increase in lift, the greater the decrease in lift-to-drag ratio. The lift-to-drag ratio is the ratio of lift to drag, where drag consists of zero-lift drag and induced drag. The percentage of these two parts of drag in the total drag is very different in low-speed flight and high-speed horizontal flight. Induced drag accounts for the main part when flying at low speeds; zero-lift drag accounts for the main percentage when flying at high speeds. In general, the zero-lift drag coefficient does not change much during flight and can be considered a constant. The applicant's prior patent 202410659554.6 "A method for reducing the drag of the entire aircraft" analyzed the induced drag and concluded that, unlike zero-lift drag, the essence of induced drag is the projection of the aerodynamic resultant force (aerodynamic force vector) acting on the wing in the X-axis direction of the track coordinate system.

[0015] According to the orientation of the aerodynamic force vector (i.e. the angle and orientation between the resultant aerodynamic force and the Y axis of the track coordinate system), the projection has three results: positive, negative and zero. Among them, negative is drag, positive is thrust, and zero is no drag. Therefore, when designing the wing structure, the final result of the induced drag can be changed in the desired direction by controlling or changing the vector direction of the aerodynamic force.

[0016] Figure 7 The embodiment of the present invention adopts a design structure of full-slot flaps (canopy wings) to increase lift and reduce drag. Compared with the applicant's prior patent CN02133862.0 "a canopy wing for increasing lift and stall angle of attack", the chord length of the upper wing surface covered by the full-slot flap of the present invention is changed from the 67% layout of the prior patent CN02133862.0 to the 100% layout of the present invention (i.e., the full-slot flap covers 100% of the chord of the upper wing surface), and the gap between the full-slot flap and the upper wing surface of the basic wing is shortened from the 30% aerodynamic chord length of the prior patent CN02133862.0 to the 5% - 10% aerodynamic chord length of the present invention. After experimental verification, although the zero-lift drag of the whole machine is slightly increased, the induced drag of the whole machine is greatly eliminated.

[0017] The basic wing uses a laminar airfoil with a relatively large thickness to obtain a larger lift coefficient. Preferably, the relative thickness of the wing of a low-speed aircraft is approximately 12-18%, the relative thickness of the wing of a subsonic aircraft is approximately 10-15%, and the relative thickness of the wing of a supersonic aircraft is approximately 3-5%.

[0018] Furthermore, a retractable and movable lift-enhancing and drag-reducing leading edge slat is connected to the leading edge of the basic wing. The moving direction of the lift-enhancing and drag-reducing leading edge slat is to translate forward along the average aerodynamic chord of the airfoil of the basic wing, then move downward relative to the average aerodynamic chord of the airfoil, then rotate at an angle β relative to the average aerodynamic chord of the airfoil, and finally adjust the vertical distance between the trailing edge of the lift-enhancing and drag-reducing leading edge slat and the upper wing surface of the leading edge of the basic wing; the basic wing, the lift-enhancing and drag-reducing leading edge slat and the full-slotted flap together constitute an integral wing.

[0019] Specifically, the lift-enhancing and drag-reducing leading edge slats can be retracted and extended relative to the leading edge of the base wing. When the aircraft flies at a small angle of attack, the aerodynamic force (pressure at this time) presses it against the wing, and it is in a closed state. If the angle of attack increases, the aerodynamic force (suction at this time) at the leading edge of the wing sucks it open. This is because the leading edge of the wing is pressure at a small angle of attack, but becomes suction at a large angle of attack. The lift-enhancing and drag-reducing leading edge slats form a gap with the leading edge of the base wing by moving, and the size and position of the gap change with the flight state.

[0020] The shape of the lift-enhancing and drag-reducing leading edge slat of the present invention is similar to that of the conventional leading edge slat, but the shape and relative orientation of the lift-enhancing and drag-reducing leading edge slat are different from those of the conventional leading edge slat. Figure 4 As shown. When the traditional leading edge slat is opened, it forms a gap with the leading edge surface of the basic wing. This gap forms an airflow channel. The airflow with higher pressure on the lower wing surface is accelerated through this gap and flows to the upper wing surface, allowing the airflow to accelerate and blow away the turbulent boundary layer on the upper wing surface of the front part of the airfoil to delay airflow separation, increase the attachment energy of the airflow in the boundary layer of the upper wing surface, reduce the pressure difference between the upper and lower wing, increase the critical stall angle of attack of the aircraft, avoid stalling at large angles of attack, and improve the lift coefficient. However, the traditional leading edge slat only increases the stall angle of attack and improves lift, but does not reduce drag. The lift-enhancing and drag-reducing leading edge slat of the present invention has a dual role. On the one hand, it can increase lift, and on the other hand, it can reduce induced drag. The lift-enhancing and drag-reducing leading edge slat changes the relative position (displacement and angle) between the leading slit and the basic wing, so that the pressure distribution on the upper wing surface has a significant change. The position and direction of the lift-enhancing and drag-reducing leading edge slat relative to the leading edge of the basic wing are very important. As shown Figure 5 As shown in the figure, the values ​​of parameters a, b, C and β determine the pressure distribution of air flow when it passes through the gap, which directly affects the lift increase and drag reduction effect. Therefore, it is necessary to obtain optimized and appropriate parameters through CFD simulation and wind tunnel tests.

[0021] The parameters of the relative position of the lift-enhancing and drag-reducing leading edge slats and the basic wing when the leading edge slats are in operation are selected as follows:

[0022] The procedure for establishing the correct relative orientation includes:

[0023] (1) The average aerodynamic chord (chord) of the basic wing is moved forward by a;

[0024] (2) downward translation b relative to the chord;

[0025] (3) Angle β rotation relative to the chord;

[0026] (4) Adjust the vertical distance C between the trailing edge of the lift-enhancing and drag-reducing leading edge slat and the leading edge upper wing surface of the basic wing.

[0027] The empirical numerical ranges of the four parameters a, b, C and β are as follows:

[0028] b / a = 0.25–0.40;

[0029] C / a = 0.15–0.35;

[0030] β = 0 – 35°;

[0031] Preferably, the present invention provides a set of empirical data for reference in calculation: b / a = 0.31; C / a = 0.28; β = 16°. After using the parameters of the above empirical data, a relatively satisfactory result is obtained: the aerodynamic force on the leading edge of the lift-increasing and drag-reducing leading edge slat points forward (in the direction of aircraft movement), and this force pointing forward is combined with the aerodynamic force of the basic wing, so that the aerodynamic vector of the entire wing is biased toward the front compared to the original basic wing, thereby reducing the induced drag of the entire wing.

[0032] like Figure 4 As shown in the figure, the leading edge slats for increasing lift and reducing drag increase lift, and at the same time change the aerodynamic force vector θ generated by the basic wing. After force vector synthesis, the resultant force vector R is close to the Y axis (Yh), which is 13.5 degrees less than when there is only a basic wing. The projection of the aerodynamic force on the X axis (Xh) of the track coordinate system (the first induced drag factor) is reduced by 0.24, and the effect of reducing induced drag is considerable. Figure 6 The figure shows the comparison of lift lines and polar curves before and after the basic wing is installed with and without the lift-increasing and drag-reducing leading edge slats. It can be seen that the lift-increasing and drag-reducing effect after the lift-increasing and drag-reducing leading edge slats are installed is very significant.

[0033] When the lift-enhancing and drag-reducing leading edge slats are opened, the high-speed inlet airflow is turned into a low-speed airflow, and the generated airflow flows out from the lift-enhancing and drag-reducing leading edge slats to form an upward airflow, thereby increasing the lift of the wing. During the takeoff and landing phases, the lift-enhancing and drag-reducing leading edge slats are opened to provide greater lift, making the takeoff and landing of the aircraft safer and more stable.

[0034] Furthermore, wingtip trapped vortex generators for active lift increase are installed at the wingtips of the integral wing. When viewed from the cockpit, the wingtip trapped vortex generators on the left wing side are in a counterclockwise direction, and the wingtip trapped vortex generators on the right wing side are in a clockwise direction.

[0035] Specifically, a wing tip trapped vortex generator is installed at the end of the integral wing (main wing). By properly installing a propeller power unit near the wing tip, the wing tip trapped vortex generator can be transformed into an active wing tip trapped vortex generator, which can further actively increase lift. In addition, the active wing tip trapped vortex generator increases the effective aspect ratio of the wing, further reduces the induced drag (the second induced drag, which is proportional to the square of the lift coefficient), increases the efficiency of the airflow conversion from two dimensions to three dimensions, and thus increases lift. 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), preventing the airflow on the lower wing surface of the basic wing from flowing to the upper wing surface of the basic wing.

[0036] Furthermore, a pair of auxiliary wings are arranged on both sides of the aircraft, the trailing edge of the auxiliary wing's airfoil faces forward, and the leading edge of the auxiliary wing's airfoil faces backward (reverse airfoil layout), and the aerodynamic force vector of the auxiliary wing is inclined toward the front of the movement; the auxiliary wing adopts a laminar airfoil with a relatively large thickness; the lift surface area of ​​the auxiliary wing is the same as the lift surface area of ​​the horizontal tail; the installation angle of the auxiliary wing is larger than the installation angle of the integral wing and is adjustable; the airfoil profiles of the auxiliary wing and the integral wing are different.

[0037] Preferably, the present invention installs an auxiliary wing on the basis of the existing configuration, and the auxiliary wing adopts a reverse airfoil, that is, the trailing edge of the auxiliary wing airfoil faces forward, and the leading edge of the auxiliary wing airfoil faces backward. The installation angle of the auxiliary wing is larger than the installation angle of the overall wing (main wing) and is adjustable; the auxiliary wing and the overall wing (main wing) have different airfoil profiles, and the auxiliary wing constitutes the offset wing of the basic wing. The aerodynamic force vector of the offset wing is inclined toward the front of the movement, offsetting and eliminating most of the induced drag generated by the lift, so that the pointing direction of the total force vector of the whole machine is as close as possible to the vertical track axis, so as to achieve the best effect of reducing induced drag.

[0038] Furthermore, the auxiliary wing is arranged behind the integral wing (main wing) along the direction of the fuselage, and the auxiliary wing, the integral wing (main wing) and the horizontal tail constitute a three-tandem wing lifting surface layout; the plane shapes of the integral wing (main wing), the auxiliary wing and the horizontal tail all adopt trapezoidal swept wings, and the lifting surface area of ​​the integral wing (main wing) is the sum of the lifting surface areas of the auxiliary wing and the horizontal tail.

[0039] The three-tandem wing lifting surface layout is composed of a normal wing and tail wing layout with a horizontal rear wing added (i.e. main wing + horizontal rear wing + horizontal tail wing). Therefore, the three-tandem wing lifting surface layout combines the advantages of the normal and canard layouts, and can obtain better aerodynamic characteristics, especially control and balancing characteristics, and the maneuverability can be significantly improved.

[0040] Furthermore, a baffle is provided at the outer end of the upper wing surface of the full-slot flap along the span direction.

[0041] The baffles can optimize aerodynamic performance and further reduce the negative effects of wingtip regurgitation.

[0042] The present invention also provides a method for constructing a full-slot flap lift-increasing and drag-reducing system, which is used to realize the full-slot flap lift-increasing and drag-reducing system as described above, comprising:

[0043] A laminar airfoil with a relatively large thickness is selected to configure the basic wing, and the lift-enhancing and drag-reducing leading edge slat is added to the leading edge of the basic wing; when the lift-enhancing and drag-reducing leading edge slat is at an angle of attack less than 8°, the aerodynamic force vector generated points to the rear, and the magnitude of the aerodynamic force vector is small at this time; when the angle of attack of the lift-enhancing and drag-reducing leading edge slat is increased to greater than 8°, the angle of the aerodynamic force vector points to the front by 45°, and the magnitude of the aerodynamic force vector is large, which is one third of the aerodynamic force vector of the basic wing;

[0044] Specifically, Figure 4 As shown in the figure, the magnitude and direction of the aerodynamic force (aerodynamic force vector) generated by the leading edge slats for increasing lift and reducing drag are different at different angles of attack α. When the angle of attack α is less than 8 degrees, the magnitude of the aerodynamic force vector is small and points to the rear. When the angle of attack α increases, the aerodynamic force vector points to the front at about 45° and the magnitude is also large, about one-third of the basic wing. Figure 4 It can be seen that the role of the leading edge slats for increasing lift and reducing drag increases lift on the one hand, and also changes the aerodynamic force vector azimuth θ generated by the basic wing. After force vector synthesis, the resultant force vector is close to the Y axis (Yh), which is 13.5 degrees smaller than when there is only a basic wing.

[0045] The fully slotted flap completely covers the upper wing surface of the basic wing, so that the fully slotted flap is 100% arranged above the upper wing surface of the basic wing; the gap between the fully slotted flap and the upper wing surface of the basic wing is set to 5% - 10% of the aerodynamic chord length; the fully slotted flap is a thin wing with an airfoil section and a small thickness, which is made of a light specific gravity, high strength and high rigidity material;

[0046] The present invention sets the full-slot flap to cover the upper wing surface with a 100% layout and a gap of 5%-10% of the aerodynamic chord length. After experimental verification, an extremely high lift coefficient more than 3 times higher than the basic airfoil lift coefficient is obtained. Although the zero-lift drag of the whole machine is slightly increased, the induced drag of the whole machine is basically eliminated.

[0047] A pair of auxiliary wings with a reverse airfoil layout are installed in series behind the integral wing (main wing) of the aircraft fuselage, a laminar airfoil with a relatively large thickness is selected to configure the auxiliary wing, a trapezoidal swept wing is used to construct the plane shape of the integral wing (main wing), the auxiliary wing and the horizontal tail, and the lift surface area ratio of the integral wing (main wing), the auxiliary wing and the horizontal tail is set to 2:1:1; the lift-to-drag ratio is increased from 10 to more than 30;

[0048] Specifically, auxiliary wings are provided to form a three-tandem wing lifting surface layout, thereby eliminating induced drag.

[0049] In one embodiment, the total area of ​​the three pairs of lifting surfaces of the integral wing (main wing), the auxiliary wing and the horizontal tail is 2500 square meters.

[0050] Preferably, both the integral wing (main wing) and the auxiliary wing adopt airfoils with high lift coefficients.

[0051] Wing tip trapped vortex generators are installed at the wing tips of the basic wing, and lift is actively increased by the wing tip trapped vortex generators while reducing induced drag, thereby obtaining a higher lift coefficient than that of the basic wing.

[0052] In one embodiment, installing wingtip trapped vortex generators obtains a lift that is more than three times higher than the lift coefficient of the basic wing, and significantly reduces the induced drag of the entire aircraft, increases the lift-to-drag ratio, and shortens the takeoff run distance, which is nearly half the distance of the original run distance with only the basic wing.

[0053] The present invention also provides a computer-readable storage medium having a computer program stored thereon, and when the program is executed by a processor, the method for constructing the full-slot flap lift-increasing and drag-reducing system as described above is implemented.

[0054] The present invention also provides a computer device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the method for constructing the full-slot flap lift-increasing and drag-reducing system as described above is implemented.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] The full-slotted flap lift-increasing and drag-reducing system and the construction method thereof provided by the present invention comprehensively consider the lift-increasing and drag-reducing schemes of the wing, solve the problem of lift-increasing leading to a decrease in lift-to-drag ratio from a global and overall perspective, and develop and design drag-reducing equipment while constructing the lift-increasing system, so that the lift as the numerator is increased and the drag as the denominator is reduced, and the lift and the drag are optimized at the same time, thereby obtaining a large lift-to-drag ratio, improving flight efficiency, and being beneficial to energy saving (fuel saving or electricity saving), so that the aircraft can fly faster and farther and stay in the air longer; the taxiing distance is shortened, a large amount of land resources are saved, and energy saving, emission reduction, low carbon and green travel are achieved; and the full-slotted flap lift-increasing and drag-reducing system has a simple and reasonable structure and a low cost, which is conducive to popularization and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the following detailed description of the preferred embodiment.The drawings are only for the purpose of illustrating the preferred embodiments and are not to be construed as limiting the invention.

[0058] In the attached picture:

[0059] Figure 1 The lift coefficient comparison chart for different angles of attack;

[0060] Figure 2 The data diagram of lift-increasing effect and lift-to-drag ratio of different airfoils;

[0061] Figure 3 It is a schematic diagram of the installation structure of a full-slotted flap and a lift-enhancing and drag-reducing leading edge slat according to an embodiment of the present invention;

[0062] Figure 4 Schematic diagram of the magnitude and direction of the aerodynamic force vector generated at different angles of attack;

[0063] Figure 5 A diagram for selecting relative position parameters of the lift-increasing and drag-reducing leading edge slat and the integral wing (main wing) of the present invention;

[0064] Figure 6 A comparison diagram of lift lines and polar curves before and after the basic wing is installed with and without the lift-enhancing and drag-reducing leading edge slats;

[0065] Figure 7 It is a schematic structural diagram of a full-slotted flap lift-increasing and drag-reducing system according to an embodiment of the present invention;

[0066] Figure 8 The figure is a schematic diagram of the structure of a computer device according to an embodiment of the present invention.

[0067] The symbols in the accompanying drawings are:

[0068] 1. Basic wing; 2. Leading edge slats for increasing lift and reducing drag; 3. Fully slotted flaps; 4. Wing tip trapped vortex generators; 5. Baffles. DETAILED DESCRIPTION

[0069] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and products consistent with some aspects of the present disclosure as detailed in the appended claims.

[0070] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. The singular forms of "a", "said" and "the" used in this disclosure and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0071] It should be understood that although the terms first, second, third, etc. may be used in the present disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present disclosure, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0072] The embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0073] Example

[0074] This embodiment is a super-large transport aircraft equipped with a full-slot flap lift-enhancing and drag-reducing system (full-slot flaps for lift-enhancing and drag-reducing). The full-slot flap lift-enhancing and drag-reducing system is arranged on both sides of the super-large transport aircraft fuselage, such as Figure 3 As shown, it includes: a basic wing 1 and a full-slotted flap 3. The basic wing 1 adopts a laminar airfoil with a relatively large thickness. The full-slotted flap 3 is arranged above the basic wing 1, close to the upper wing surface of the basic wing 1, and has a gap between the upper wing surface; the full-slotted flap 3 covers the entire span length of the upper wing surface in the span direction, and the curvature of the full-slotted flap 3 is the same as the curvature of the upper wing surface; the full-slotted flap 3 is a thin wing with an airfoil section and a small thickness, which is made of a light specific gravity, high strength and high stiffness material.

[0075] Figure 3 Part 3a shows the state when the full slot flap 3 and the lift-enhancing and drag-reducing leading edge slat 2 are not opened, and part 3b shows the state when the full slot flap 3 and the lift-enhancing and drag-reducing leading edge slat 2 are opened.

[0076] The main parameters and basic performance of the super-large transport aircraft are as follows:

[0077] Maximum take-off weight: 1,500 tons (for comparison: the US Boeing Pelican is 1,270 tons; the Russian AN-225 is 600 tons);

[0078] Commercial payload: 1,042 tons (equivalent to 22 20-ton fighter planes; or 10,000 fully armed soldiers);

[0079] Fuel: 450 tons;

[0080] Power: turbofan engine, maximum thrust is 375,000 kg;

[0081] Cruising altitude: 11 km;

[0082] Cruising speed: Mach 0.7 (680 km / h);

[0083] Maximum range: 11769 km;

[0084] The original model of this super-large transport aircraft has a normal aerodynamic layout. In order to increase the lift-to-drag ratio from 10 to 30, this embodiment adopts the latest patented technology of full-slot flap lift increase. In addition to the flaps, a pair of auxiliary wings with a reverse airfoil layout are installed in series behind the integral wing (main wing) on ​​the fuselage to completely eliminate induced drag. From front to back, the lifting surface area ratio of the integral wing (main wing), auxiliary wing and horizontal tail is configured to be 2:1:1. The total area of ​​the three pairs of lifting surfaces of the integral wing (main wing), auxiliary wing and horizontal tail is 2,500 square meters. Their plane shapes are all trapezoidal swept wings, which are suitable for high subsonic flight. The geometric dimensions of the three pairs of lifting surfaces are as follows:

[0085] Overall wing (main wing): wingspan: 130 meters; chord: 9.63 meters; aspect ratio: 13.52; area: 1250 square meters;

[0086] Auxiliary wing: wingspan: 86 meters; chord: 7.27 meters; aspect ratio: 11.83; area: 625 square meters;

[0087] Horizontal tail: wingspan: 86 meters; chord: 7.27 meters; aspect ratio: 11.83; area: 625 square meters.

[0088] Fuselage length: 156 meters;

[0089] Airfoil: Both the integral wing (main wing) and the auxiliary wing use laminar airfoils with a larger relative thickness to obtain a larger lift coefficient.

[0090] The method of using the combined effects of aerodynamic vectors to offset each other can achieve the goal of eliminating or substantially eliminating the induced drag of the entire aircraft.

[0091] Lift-enhancing technology: Adopting high lift coefficient airfoil (QYX-5), full slotted flap configuration with lift-enhancing and drag-reducing leading edge slot 2;

[0092] A three-tandem wing lifting surface system is used, such as Figure 7 As shown, a wing tip trapped vortex generator 4 (wing tip trapped vortex lift-increasing and drag-reducing device) is installed at the wing tip, and multiple aspects work together to send the super-large transport aircraft into the sky. A baffle 5 is set at the outer end of the full-slot flap 3 along the wingspan direction. The baffle 5 can optimize the aerodynamic performance and further reduce the wing tip backflow. The baffle 5 adjusts the airflow path and pressure distribution, reduces the occurrence of vortices and turbulence, and reduces flight resistance; and the baffle 5 can separate the air flow of the wing, help reduce aerodynamic resistance, and improve flight efficiency.

[0093] One beneficial effect of this embodiment is that an extremely high lift coefficient of 3.164 times higher than that of the basic wing is obtained. Although the zero-lift drag of the whole aircraft is slightly increased, the induced drag of the whole aircraft is basically eliminated. Another beneficial effect is that the take-off run distance is greatly shortened from 5,000 meters when there is only a basic wing to 2,762 meters. Considering the carrying capacity of the runway, the length of the airport runway (usually 2,000-3,000 meters) of the current large transoceanic passenger aircraft is completely sufficient.

[0094] The embodiment of the present invention further provides a computer device, Figure 8 is a schematic diagram of the structure of a computer device provided by an embodiment of the present invention; see the accompanying drawings Figure 8 As shown, the computer device includes: an input device 23, an output device 24, a memory 22 and a processor 21; the memory 22 is used to store one or more programs; when the one or more programs are executed by the one or more processors 21, the one or more processors 21 implement the construction method of the full-slot flap lift-increasing and drag-reducing system provided in the above embodiment; wherein the input device 23, the output device 24, the memory 22 and the processor 21 can be connected by a bus or other means, Figure 8 The example of connecting through bus is taken in the following.

[0095] The memory 22 is a readable and writable storage medium of a computing device, which can be used to store software programs and computer executable programs, such as program instructions corresponding to the construction method of the full-slot flap lift-increasing and drag-reducing system described in the embodiment of the present invention; the memory 22 can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system and at least one application required for a function; the data storage area can store data created according to the use of the device, etc.; in addition, the memory 22 can include a high-speed random access memory, and can also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device; in some instances, the memory 22 can further include a memory remotely arranged relative to the processor 21, and these remote memories can be connected to the device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0096] The input device 23 may be used to receive input digital or character information, and to generate key signal input related to user settings and function control of the device; the output device 24 may include a display device such as a display screen.

[0097] The processor 21 executes various functional applications and data processing of the device by running the software programs, instructions and modules stored in the memory 22, that is, realizes the construction method of the full-slotted flap lift-enhancing and drag-reducing system mentioned above.

[0098] The computer device provided above can be used to execute the construction method of the full-slotted flap lift-increasing and drag-reducing system provided in the above embodiment, and has corresponding functions and beneficial effects.

[0099] The embodiment of the present invention also provides a storage medium containing computer executable instructions, which are used to execute the construction method of the full-slot flap lift-increasing and drag-reducing system provided in the above embodiment when executed by a computer processor. The storage medium is any of various types of memory devices or storage devices, and the storage medium includes: installation media, such as CD-ROM, floppy disk or tape device; computer system memory or random access memory, such as DRAM, DDRRAM, SRAM, EDORAM, Rambus RAM, etc.; non-volatile memory, such as flash memory, magnetic media (such as hard disk or optical storage); registers or other similar types of memory components, etc.; the storage medium may also include other types of memory or a combination thereof; in addition, the storage medium may be located in the first computer system in which the program is executed, or may be located in a different second computer system, the second computer system is connected to the first computer system via a network (such as the Internet); the second computer system may provide program instructions to the first computer for execution. The storage medium includes two or more storage media that can reside in different locations (for example, in different computer systems connected via a network). The storage medium can store program instructions (for example, specifically implemented as a computer program) that can be executed by one or more processors.

[0100] Of course, the computer executable instructions of a storage medium containing computer executable instructions provided in an embodiment of the present invention are not limited to the method for constructing a full-slotted flap lift-enhancing and drag-reducing system as described in the above embodiment, and can also execute related operations in the method for constructing a full-slotted flap lift-enhancing and drag-reducing system provided in any embodiment of the present invention.

[0101] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0102] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A full-slot flap lift-increasing and drag-reducing system, characterized in that: The invention is arranged on both sides of the aircraft fuselage, and comprises: a basic wing and a full-slot flap, wherein the basic wing adopts a laminar airfoil with a relatively large thickness, and the full-slot flap is arranged above the basic wing, close to the upper wing surface of the basic wing, and has a gap between the full-slot flap and the upper wing surface; the full-slot flap covers the entire span length of the upper wing surface in the span direction, and the curvature of the full-slot flap is the same as the curvature of the upper wing surface; the full-slot flap is a thin wing with an airfoil section and a small thickness, which is made of a light specific gravity, high strength and high rigidity material; The leading edge of the basic wing is connected with a retractable and movable lift-enhancing and drag-reducing leading edge slat; the extending and moving direction of the lift-enhancing and drag-reducing leading edge slat is to translate forward along the average aerodynamic chord of the airfoil of the basic wing, then move downward relative to the average aerodynamic chord of the airfoil, then rotate at an angle β relative to the average aerodynamic chord of the airfoil, and finally adjust the vertical distance between the trailing edge of the lift-enhancing and drag-reducing leading edge slat and the upper wing surface of the leading edge of the basic wing; the basic wing, the lift-enhancing and drag-reducing leading edge slat and the full-slotted flap together constitute an integral wing; The parameters of the relative position of the lift-enhancing and drag-reducing leading edge slats and the basic wing when the leading edge slats are in operation are selected as follows: The procedure for establishing the correct relative orientation includes: (1) Move forward a along the mean aerodynamic chord of the basic wing; (2) Downward translation b relative to the mean aerodynamic chord of the airfoil; (3) Angle β relative to the mean aerodynamic chord of the airfoil; (4) Adjust the vertical distance C between the trailing edge of the lift-enhancing and drag-reducing leading edge slat and the upper wing surface of the leading edge of the basic wing; The empirical numerical ranges of the four parameters a, b, C and β are as follows: b / a = 0.25–0.40; C / a = 0.15–0.35; β= 0 – 35°； The wing tip of the integral wing is provided with a wing tip trapped vortex generator for active lift increase. When viewed from the cockpit, the wing tip trapped vortex generator on the left wing is in a counterclockwise direction, and the wing tip trapped vortex on the right wing is in a clockwise direction. A pair of auxiliary wings are also arranged on both sides of the aircraft, the trailing edge of the airfoil of the auxiliary wing faces forward, the leading edge of the airfoil of the auxiliary wing faces backward, and the aerodynamic force vector of the auxiliary wing is inclined toward the front of the movement; the auxiliary wing adopts a laminar airfoil with a relatively large thickness; the lifting surface area of ​​the auxiliary wing is the same as the lifting surface area of ​​the horizontal tail; the installation angle of the auxiliary wing is larger than the installation angle of the integral wing and is adjustable; the airfoil profiles of the auxiliary wing and the integral wing are different; The auxiliary wing is arranged behind the integral wing along the fuselage direction, and the auxiliary wing, the integral wing and the horizontal tail constitute a three-tandem wing lifting surface layout; the plane shapes of the integral wing, the auxiliary wing and the horizontal tail all adopt a trapezoidal swept wing, and the lifting surface area of ​​the integral wing is the sum of the lifting surface areas of the auxiliary wing and the horizontal tail; The outer end of the upper wing surface of the full-slot flap along the wingspan direction is provided with a baffle.

2. A method for constructing a full-slot flap lift-increasing and drag-reducing system, used to realize the full-slot flap lift-increasing and drag-reducing system as claimed in claim 1, characterized in that: include: A laminar airfoil with a relatively large thickness is selected to configure the basic wing, and the lift-enhancing and drag-reducing leading edge slat is added to the leading edge of the basic wing; when the lift-enhancing and drag-reducing leading edge slat is at an angle of attack less than 8°, the aerodynamic force vector generated points to the rear, and the magnitude of the aerodynamic force vector is small at this time; when the angle of attack of the lift-enhancing and drag-reducing leading edge slat is increased to greater than 8°, the angle of the aerodynamic force vector points to the front by 45°, and the magnitude of the aerodynamic force vector is large, which is one third of the aerodynamic force vector of the basic wing; The fully slotted flap completely covers the upper wing surface of the basic wing, so that the fully slotted flap is 100% arranged above the upper wing surface of the basic wing; the gap between the fully slotted flap and the upper wing surface of the basic wing is set to 5%-10% of the aerodynamic chord length; the fully slotted flap is a thin wing with an airfoil section and a small thickness, which is made of a light specific gravity, high strength and high rigidity material; A pair of auxiliary wings with a reverse airfoil layout are installed in series behind the integral wing of the aircraft fuselage, a laminar airfoil with a relatively large thickness is selected to configure the auxiliary wing, a trapezoidal swept wing is used to construct the plane shape of the integral wing, the auxiliary wing and the horizontal tail, and the lift surface area ratio of the integral wing, the auxiliary wing and the horizontal tail is set to 2:1:1; the lift-to-drag ratio is increased from 10 to more than 30; Wing tip trapped vortex generators are installed at the wing tips of the basic wing, and lift is actively increased by the wing tip trapped vortex generators while reducing induced drag, thereby obtaining a higher lift coefficient than that of the basic wing.

3. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method for constructing a full-slotted flap lift-increasing and drag-reducing system according to claim 2 is implemented.

4. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the method for constructing the full-slotted flap lift-enhancing and drag-reducing system as claimed in claim 2 is implemented.

Images