CN114476020B - Lift-increasing device for wings and aircraft - Google Patents

Abstract

The invention relates to a high lift device for a wing and an airplane, wherein the high lift device for the wing comprises a fixed wing, a leading edge slat and a rotating body, wherein the fixed wing is used for generating lift force for the airplane to fly; the leading edge slat is connected with the fixed wing and can move between a recovery position and a deployment position relative to the fixed wing, and is used for controlling the separation of the air flow at the leading edge of the fixed wing and improving the stall attack angle and the maximum lift coefficient; the rotator is coupled to the slats and is rotatable to fill a cavity formed by the slats in a deployed position. The invention can reduce the aerodynamic noise of the front edge slat in the take-off or landing stage of the aircraft, simultaneously reduce the differential pressure resistance of the aircraft generated by the slat concave cavity, improve the aerodynamic performance, and has simple structure and stronger feasibility.

Description

Lift-increasing device for wings and aircraft

Technical field

The invention relates to the field of high-lift aircraft, and in particular to a lift-increasing device for wings with low noise characteristics and an aircraft.

Background technique

The external noise level of large passenger aircraft is a core indicator of "environmental protection" and an important evaluation criterion for airworthiness certification. ICAO's Noise Airworthiness Regulations stipulate noise control standards for aircraft approach and takeoff. Since December 2017, Europe and the United States have begun to implement the fifth stage of civil aircraft noise airworthiness regulations, requiring the cumulative noise margin to be further reduced by 7EPNdB compared with the fourth stage standard. This provision applies to aircraft types that apply for airworthiness certificates after December 31, 2017, and puts forward more stringent requirements for the airworthiness certification of my country's C919 large passenger aircraft and CR929 long-range wide-body passenger aircraft. The external noise of the aircraft mainly comes from the engine and the aircraft body. Especially during the landing stage of the aircraft, the magnitude of the aircraft body noise has exceeded the magnitude of the engine noise and has become the main aircraft noise source. The leading edge slat noise of an aircraft is one of the important components of the aircraft body noise.

Nowadays, the leading edge device of the high-lift system of large civil aircraft usually takes the form of slats. The traditional leading edge slat shape matches the leading edge of the aircraft's fixed wing so that the leading edge slats can be retracted by a high-lift mechanism to form a clean airfoil during cruising. For this reason, the rear surface of the designed leading edge slat usually forms a cavity area. When the leading edge slats are open, the incoming flow will form a low-speed backflow area in this cavity area. This low-speed recirculation area is mainly composed of a strong large-scale vortex, and the flow structure in this cavity area is very unstable, causing the leading edge slat to produce strong radiation noise.

In order to reduce the radiation level of the aerodynamic noise of the leading edge slats, researchers proposed the slat cavity filling technology (SlatCove Filler, SCF), which is to form a filled slat (SCF slat). However, in order to ensure that the aerodynamic performance of the high-lift system is not weakened, the shape of the leading edge of the fixed wing must remain unchanged. However, this will cause the shape of the rear surface of the leading edge slats to not match the shape of the leading edge of the fixed wing, causing the leading edge slats to be in the cruise device. Can't be folded down.

Contents of the invention

The purpose of the present invention is to solve the shortcomings existing in the prior art. The present invention aims to provide a lift-increasing device for wings and an aircraft to solve the above-mentioned problems existing in the prior art.

The above technical objectives of the present invention will be achieved through the technical solutions described below.

A lift-increasing device for an aircraft wing, which is used for an aircraft. The lift-increasing device for an airfoil includes a fixed wing, a leading edge slat and a rotating body.

Wherein, the fixed wing is used to generate lift for aircraft flight;

The leading edge slats are connected to the fixed wing and can move between the retracted position and the deployed position relative to the fixed wing to control airflow separation at the leading edge of the fixed wing and increase the stall angle of attack and maximum lift coefficient;

The rotary body is connected to the leading edge slat, and the rotary body is rotatable for filling the cavity formed by the leading edge slat in the deployed position.

Based on the above aspect and any possible implementation, an implementation is further provided, in which the leading edge slat is connected to the fixed wing through a guide rail, and the leading edge slat is recovered and deployed through the guide rail action.

According to the above aspect and any possible implementation, an implementation is further provided, the fixed wing includes a leading edge upper surface and a leading edge lower surface; the leading edge slat includes a slat upper surface and a slat rear surface. The upper surface of the slat and the rear surface of the slat form a continuous contour surface with the upper surface of the fixed wing leading edge and the lower surface of the fixed wing leading edge respectively when the leading edge slat is in the retracted position.

According to the above aspects and any possible implementation, an implementation is further provided, which further includes an actuating component, the actuating component is disposed inside the rear surface of the slat, and the rotary body is in the actuating part. It rotates driven by moving parts.

According to the above aspect and any possible implementation, an implementation is further provided. The rotating body includes an upper surface, a lower surface and a rear surface. The upper surface and the lower surface are in contact with the position of the rotating body. The slat upper surface and the slat rear surface have the same curvature respectively, and the rear surface and the slat rear surface form a continuous surface when the leading edge slat is in the retracted position.

According to the above aspect and any possible implementation, an implementation is further provided, which also includes a hinge provided on the slat rear surface of the leading edge slat, and the rotating body is connected to the slat through the hinge. Leading edge slat connection.

Based on the above aspects and any possible implementation, an implementation is further provided, in which the actuating component is a spring mechanism or a hydraulic mechanism.

According to the above aspects and any possible implementation, an implementation is further provided, in which the hinge is connected at the junction of the rear surface and the lower surface of the rotating body, and the rotating body rotates counterclockwise around the hinge. Rotate outward.

The invention also provides an aircraft, which includes the lift-increasing device for wings according to the invention.

Based on the above aspects and any possible implementation, an implementation is further provided. When the aircraft is in the take-off or landing stage, the leading edge slats are in the open position, and at the same time, the rotating body rotates outward to open, forming a pair of slats. Filling of the leading edge slat cavity; when the aircraft is in the cruise stage, the rotary body is recovered inwardly into the leading edge slat, and at the same time, the leading edge slat is recovered to the leading edge of the fixed wing .

Beneficial technical effects of the present invention

An embodiment of the present invention provides a lift-increasing device for an airfoil, which is used on an aircraft. The lift-increasing device for an airfoil includes a fixed wing, a leading edge slat and a rotating body. The leading edge slat is connected to the fixed wing, and The fixed wing can move between a retracted position and a deployed position relative to the fixed wing; the rotating body is connected to the leading edge slat, and the rotating body can rotate to fill the leading edge slat formed in the deployed position. cavity. The rotary body of the present invention forms a continuous curved surface with the slat in the retracted position, so that it can completely match the leading edge of the fixed wing when the slat is retracted. During the take-off or landing phase of the aircraft, the rotating body opens inward to fill the slat cavity to achieve a noise reduction effect. Compared with the existing technology, the technical solution of the present invention is more feasible.

Description of the drawings

Below, the embodiments of the present invention are described in detail with reference to the accompanying drawings, wherein:

Figure 1 is a schematic structural diagram of a lift-increasing device for an airfoil in an embodiment of the present invention;

Figure 2 is a schematic structural diagram of the leading edge slats in the unfolded position when the aircraft is taking off or landing in an embodiment of the present invention;

Figure 3 is a schematic structural diagram of the leading edge slat rotating body retracted in the embodiment of the present invention;

Figure 4 is a schematic diagram of the wing during the cruise stage of the aircraft in the embodiment of the present invention;

Figure 5 is a schematic diagram of the geometric comparison between the 30P30N basic type and the slat configuration of the present invention;

Figure 6 is a schematic diagram comparing the speed cloud distribution of the 30P30N basic type and the slat configuration of the present invention when the angle of attack AoA=8 degrees;

Figure 7 is a schematic diagram comparing the pressure cloud distribution of the 30P30N basic type and the slat configuration of the present invention when the angle of attack AoA=8 degrees;

Figures 8(a), 8(b) and 8(c) are schematic diagrams comparing the surface pressure coefficients of the 30P30N basic type and the slat configuration of the present invention when the angle of attack is 4 degrees, 8 degrees and 12 degrees;

Figure 9 is a schematic diagram comparing the lift curves of the 30P30N basic type and the slat configuration of the present invention;

Figure 10 is a schematic diagram comparing the resistance curves of the 30P30N basic type and the slat configuration of the present invention;

Figure 11 is a schematic diagram comparing the radiation noise spectrum of the 30P30N basic type and the slat configuration of the present invention.

Detailed ways

In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, a detailed description will be given below with reference to the drawings and specific embodiments, but the implementation of the present invention is not limited thereto.

As shown in Figure 1, the wing lift device of the present invention includes a fixed wing 10, a leading edge slat 30 and a rotating body 20.

Wherein, the fixed wing 10 is used to generate lift for aircraft flight;

The leading edge slat 30 is connected to the fixed wing 10 and can move between the retracted position and the deployed position relative to the fixed wing 10, and is used to control the leading edge airflow separation of the fixed wing 10, improve the stall angle of attack and Maximum lift coefficient;

The rotary body 20 is connected to the leading edge slat 30, and the rotary body 20 can rotate to fill the cavity formed by the leading edge slat 30 in the deployed position.

The rotating body in the present invention is implemented by the rotatable body 20 .

Preferably, the leading edge slat 30 described in the embodiment of the present invention has a leading edge upper surface 31, a rear surface 35, a lower arc surface 33, a first lower surface 37 and a second lower surface 39. A rotatable body 20 is provided at the lower tip of the slat leading edge 30 . The rotatable body 20 has three surfaces: an upper surface 25, a lower surface 21 and a rear surface 23. The lower arc surface 33 of the leading edge slat 30 is tangent to the lower surface 21 of the rotating body 20. The rotating body 20 is recovered into the cavity of the leading edge slat 30. The cavity is formed by the The leading edge slat 30 is composed of a lower arc surface 33 , a first lower surface 37 and a second lower surface 39 , and the cavity is used to accommodate the rotating body 20 . The rear surface 23 of the rotating body and the rear surface 35 of the leading edge slat 30 form a continuous contour surface. There is a small space between the second lower surface 39 of the leading edge slat 30 and the upper surface 21 of the rotary body 20 and they do not completely overlap, mainly to increase the reliability of the rotary body 20 .

Preferably, the lower arc surface 21 and the rear surface 23 of the rotary body 20 are respectively the same as the curvatures of the slat upper surface 31 and the slat rear surface 35 at the position of the rotary body. The rear surface 23 of the rotating body 20 is a part of the leading edge slat rear surface 35, and the lower arc surface 21 of the rotating body is tangent to the leading edge slat upper surface 31.

Preferably, the fixed wing 10 includes a leading edge upper surface 11 and a leading edge lower surface 13. Different fluids flow through the leading edge upper surface 11 and the lower surface 13, and the flow speeds are also different, thus generating different pressures. The leading edge The pressure difference between the upper surface 11 and the lower surface 13 of the leading edge is the lift required for aircraft flight. The leading edge slat 30 has two different positions relative to the fixed wing 10, namely a retracted position and a deployed position. The leading edge slat 30 is operably connected to the fixed wing 10 through guide rails (not shown). When the aircraft takes off or lands, the leading edge slat 30 unfolds forward to form a gap with the fixed wing 10, and a gap will be formed in the gap. The high-speed airflow suppresses flow separation at the leading edge of the fixed wing 10 and increases the stall angle of attack and maximum lift coefficient; when the aircraft is cruising, the leading edge slat 30 is recovered to the fixed wing 10, and the rear surface 35 of the leading edge slat 30 is in contact with the fixed wing The leading edge upper surface 11 of 10 and the leading edge lower surface 13 are completely matched to form a clean wing, and the recovery and deployment of the leading edge slats 30 are realized through guide rails.

The slat upper surface 31 and the slat rear surface 35 of the leading edge slat 30 are arranged to form a continuous contour curved surface with the fixed wing leading edge upper surface 11 and leading edge lower surface 13 respectively in the retracted position.

Preferably, the rotatable element 20 is fixed on the rear surface 35 of the leading edge slat 30 through a hinge 61 . The hinge 61 is provided at the junction of the rear surface 25 and the lower surface 23 of the rotatable element 20 , and the rotatable element 20 rotates outward around the hinge 61 . The connection is movable and not fixed. The rotatable element 20 rotates inwardly to the slat rear surface 35 thereby configuring the cavity to fill the slat. An actuating component is provided inside the rear surface 35 of the leading edge slat 30 , and the rotatable element 20 rotates driven by the actuating component. Among them, the actuating component includes a spring mechanism or a hydraulic mechanism.

Specifically, as shown in Figures 2 and 3, when the aircraft is in the take-off or landing state, the rotatable element 20 at the lower tip of the leading edge slat 30 can use actuating components such as a spring mechanism or a hydraulic mechanism (not shown) Automatically rotates outward to the deployed position to form a complete cavity filling shape, which meets the cavity filling leading edge slat shape contour, thereby reducing noise and reducing drag; as shown in Figure 4, when the aircraft is in cruising state, The leading edge slat 31 moves from the deployed position to the retracted position. The rotatable element 20 at the lower tip of the leading edge slat 30 automatically rotates inward through the actuating mechanism and is recovered into the leading edge slat 30. At the same time, the leading edge slat 30 is recovered. To the leading edge of the wing main wing 10, the rear surface 35 of the leading edge slat 30 and the rear surface 25 of the rotatable element 20 form a continuous curved surface. This continuous curved surface seamlessly matches the leading edge surface 11 of the wing main wing, and the outline is complete. high speed cruising wing. The actuating components for retracting and deploying the rotatable element 20 move together with the leading edge slat 30 .

In order to verify the technical effect of the slat configuration of the present invention (i.e., the lift-increasing device for wings), the present invention takes the 30P30N type as the basic configuration and compares it with the lift-increasing device for wings proposed by the present invention. Figure 5 shows a geometric comparison diagram between the 30P30N basic type and the slat configuration of the present invention. It can be seen that the two configurations have very different geometric configurations in the slat cavity. Compared with the 30P30N basic type, the cavity of the slat configuration of the present invention is more streamlined. Therefore, from an aerodynamic point of view, it is shown that the slat configuration of the present invention can reduce aerodynamic resistance and the aerodynamic noise generated.

In order to compare the aerodynamic performance of the slats of the two configurations (the basic type and the slat configuration of the present invention), the present invention conducts computational fluid dynamics numerical simulation on the two configurations.

Since the distribution of velocity clouds and pressure clouds is similar at all angles of attack, the present invention only provides results when the outflow angle of attack is 8 degrees. Figures 6 and 7 show the comparison of the velocity distribution nephogram and pressure distribution nephogram near the slat of the two configurations when the angle of attack is 8 degrees. It can be seen from Figure 6 that the flow separation area in the slat cavity of the slat configuration of the present invention is smaller, and the flow speed in the gap between the fixed wing and the leading edge slat is greater. Therefore, the slat of the present invention The configuration has a greater ability to inhibit fluid separation. It can be seen from Figure 7 that the pressure in the cavity of the slat configuration of the present invention is larger, so the pressure difference resistance of the leading edge slat is smaller.

Figure 8(a), Figure 8(b) and Figure 8(c) compare the surface pressures of the two configurations at three different angles of attack (including 4 degrees of attack angle, 8 degrees of attack angle and 12 degrees of attack angle). coefficient curve. It can be seen that under these three different angles of attack, the pressure of the slat configuration of the present invention on the suction surface of the fixed wing is smaller, which is mainly due to the greater flow speed of the slat configuration of the present invention on the suction surface. , thus generating greater lift.

Figures 9 and 10 compare the lift coefficient and drag coefficient of the two slat configurations respectively. It can be clearly seen that compared with the basic leading edge slat, the new leading edge slat configuration has a higher lift coefficient and a smaller drag coefficient. Therefore, the lift-drag ratio of the slat configuration of the present invention is larger, and the aerodynamics Performance is better. Figure 11 compares the far-field noise spectrum curves of the two slat configurations. It can be seen that the slat configuration of the present invention can reduce the overall slat noise by about 3dB.

The above description shows and describes several preferred embodiments of the present invention, but as mentioned above, it should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various embodiments. other combinations, modifications and environments, and can be modified through the above teachings or technology or knowledge in related fields within the scope of the application concept described in the present invention. Any modifications and changes made by those skilled in the art that do not depart from the spirit and scope of the present invention shall be within the protection scope of the appended claims of the present invention.

Claims (8)

1. A lift-increasing device for an airfoil, characterized in that the lift-increasing device for an airfoil includes a fixed wing, a leading edge slat and a rotating body, wherein the fixed wing is used to generate lift for aircraft flight; The leading edge slat is connected to the fixed wing and can move between a retracted position and a deployed position relative to the fixed wing, and is used to control the leading edge airflow separation of the fixed wing; The rotary body is connected to the leading edge slat, and the rotary body is rotatable for filling the cavity formed by the leading edge slat in the deployed position; The fixed wing includes a leading edge upper surface and a leading edge lower surface; the leading edge slat includes a slat upper surface and a slat rear surface, and the slat upper surface and the slat rear surface are located on the leading edge slat. In the retracted position, a continuous contour surface is formed with the upper surface of the fixed wing leading edge and the lower surface of the fixed wing leading edge respectively; The rotating body includes an upper surface, a lower surface and a rear surface. The upper surface and the lower surface have the same curvature as the upper surface of the slat and the rear surface of the slat at the position of the rotating body. The rear surface A continuous surface is formed with the rear surface of the slat when the leading edge slat is in the retracted position. 2. The wing lift device according to claim 1, wherein the leading edge slat is connected to the fixed wing through a guide rail, and the recovery and deployment operations are performed through the guide rail. 3. The lift-increasing device for an airfoil according to claim 1, further comprising an actuating component, the actuating component being disposed inside the rear surface of the slat, and the rotating body is in the actuating position. It rotates driven by moving parts. 4. The wing lift device according to claim 1, further comprising a hinge provided on the slat rear surface of the leading edge slat, and the rotating body is connected to the slat through the hinge. Leading edge slat connection. 5. The wing lift device according to claim 3, wherein the actuating component is a spring mechanism or a hydraulic mechanism. 6. The lift-increasing device for an airfoil according to claim 4, wherein the hinge is connected at the junction of the rear surface of the rotary body and the lower surface of the slat, and the rotary body revolves around the The hinge rotates outward. 7. An aircraft, characterized in that the aircraft includes the wing lift device according to any one of claims 1 to 6. 8. The aircraft according to claim 7, characterized in that when the aircraft is in the take-off or landing stage, the leading edge slats are in an open position, and at the same time, the rotating body rotates outward to open, forming a gap between the leading edge slats and the leading edge slats. Filling of the wing cavity; when the aircraft is in the cruising stage, the rotary body is retracted inwardly to the inside of the leading edge slat, and at the same time, the leading edge slat is retracted to the leading edge of the main wing of the aircraft.