An airfoil structure for high frequency dynamic wind tunnel testing

Abstract

The present invention discloses an airfoil structure for high-frequency dynamic wind tunnel testing, which relates to the field of airfoil performance testing, and includes: an airfoil body, with the position of one-half of the wingspan of the airfoil body as the center plane, the upper wing surface of the airfoil body having first grooves on both sides of the center plane, the first grooves having a plurality of staggered first support strips; a lightening cover plate, the lightening cover plate is used to close the opening of the first groove at the upper wing surface, and the outer side surface of the lightening cover plate is matched with the profile of the airfoil body. The adoption of this scheme can reduce the moment of inertia of the test model while meeting the strength and stiffness requirements, and is effectively applied to high-frequency dynamic wind tunnel testing of airfoils.

Description

Technical Field

[0001] The invention relates to the field of airfoil performance testing, and in particular to an airfoil structure used for high-frequency dynamic wind tunnel testing. Background Art

[0002] In order to expand the application field of helicopters and improve their comprehensive mission effectiveness, domestic research institutions have been constantly exploring high-speed helicopters. In recent years, with the development of aviation technology, research on high-speed rotorcraft has once again become a hot topic. Helicopter technology powers, led by Europe and the United States, have been constantly trying to improve the flight performance of rotorcraft, especially the flight speed, in various ways.

[0003] As the core and key component of a helicopter, the rotor system is one of the important factors that affect the overall performance of a helicopter. As the flight speed of a helicopter increases, the aerodynamic environment faced by the rotor becomes increasingly complex, such as dynamic stall of the forward blades, expansion of the separation zone of the backward blades, and many other problems. Among them, the airfoil, as the basic component of the rotor, has a direct impact on its overall performance. Therefore, airfoil design technology is one of the key technologies in the helicopter design process.

[0004] As an important means of testing aerodynamic performance, airfoil wind tunnel testing can simulate the complex environment in which the airfoil is located, obtain the aerodynamic characteristics of the airfoil under the corresponding state, and provide experimental support for the airfoil optimization design, thus laying an important foundation for improving the comprehensive performance of the rotor.

[0005] At present, the airfoil wind tunnel tests developed in China are mainly static wind tunnel tests and low-frequency dynamic wind tunnel tests, and there is little research on high-frequency dynamic wind tunnel tests. In addition, since the test frequency involved in high-frequency dynamic wind tunnel tests is relatively high, in order to reduce the moment of inertia of the airfoil model while meeting the strength and stiffness requirements, higher requirements are placed on the design and processing of the model. Summary of the invention

[0006] The present invention aims to solve the deficiencies of the prior art and to provide an airfoil structure for high-frequency dynamic wind tunnel testing. By adopting this solution, the strength and stiffness requirements can be met while reducing the rotational inertia of the test model, and the airfoil structure can be effectively applied to high-frequency dynamic wind tunnel testing of airfoils.

[0007] The present invention is achieved through the following technical solutions:

[0008] An airfoil structure for high-frequency dynamic wind tunnel testing, comprising:

[0009] An airfoil body, with the position of one-half of the wingspan of the airfoil body as the center plane, the upper wing surface of the airfoil body is provided with first grooves on both sides of the center plane, and the first grooves are provided with a plurality of staggered first support bars;

[0010] A lightening cover plate is used to close the opening of the first groove at the upper wing surface, and the outer side surface of the lightening cover plate is matched with the profile of the airfoil body.

[0011] Compared with the prior art, the airfoil wind tunnel tests developed in China are mainly based on static wind tunnel tests and low-frequency dynamic wind tunnel tests, and there is less research on high-frequency dynamic wind tunnel tests of airfoils. In addition, since the test frequency involved in high-frequency dynamic wind tunnel tests is relatively high, the design and processing of the model are required to meet the strength and stiffness requirements while reducing the moment of inertia of the airfoil model. The present invention provides an airfoil structure for high-frequency dynamic wind tunnel tests. By adopting this solution, the strength and stiffness requirements can be met while reducing the moment of inertia of the test model, and it can be effectively applied to high-frequency dynamic wind tunnel tests of airfoils. In the specific scheme, the center plane is a vertical plane from the leading edge to the trailing edge of the airfoil body at the half position of the airfoil body in the span direction; the upper wing surface of the airfoil body is provided with a first groove on both sides of the center plane, the length direction of the first groove is arranged along the span direction of the airfoil body, and the cross-sectional shape of the first groove is preferably a polygonal shape with a wide middle and narrow ends, that is, the two ends gradually shrink, and the arc is rounded at the corner to meet the strength conditions of the wing under high-frequency vibration, avoid the main load-bearing positions at the two ends and the middle of the airfoil body without sufficient strength and rigidity, and reserve the installation position of the pressure measuring hole in the middle. The two first grooves are preferably arranged symmetrically along the center plane, and the first grooves opened can greatly reduce the mass of the airfoil body, thereby reducing the moment of inertia of the test model. A number of staggered first support bars are distributed in the first groove, and the first support bars are supported in the first groove to meet the strength and rigidity requirements required for the experiment through the first support bars; wherein, the first support bars are staggered, and the first grooves are preferably divided into honeycomb grooves to further improve the strength and rigidity. In addition, in order to maintain the shape of the airfoil body, a lightening cover is provided at the opening of the first groove, which is used to close the first groove and is adapted to the profile of the upper wing surface of the airfoil body. The above scheme can reduce the mass of the model to the maximum extent while maintaining the shape of the airfoil model in the high-frequency dynamic wind tunnel test, greatly reducing the moment of inertia of the model during high-frequency oscillation; and through a number of first support bars designed internally, the strength and rigidity of the model are ensured.

[0012] As a further way to reduce the mass of the model, the inner side of the lightening cover plate is provided with a second groove matched with the first groove, and the second groove is provided with a plurality of second support bars distributed in an interlaced manner, and the second support bars correspond to the first support bars one by one;

[0013] The opening of the first groove is provided with a first sinking step, and the circumferential end of the lightening cover is used to be placed in the first sinking step and is bolted to the first sinking step. In this solution, the lightening cover needs to have a certain thickness, and a second groove is provided on the inner side of the lightening cover, so that after the lightening cover is installed on the upper wing surface of the airfoil body, the mass of the airfoil model is further reduced; a number of staggered second support bars are provided in the second groove, and when the lightening cover is installed on the airfoil body, the second support bars and the second support bars support one by one, thereby further ensuring the strength and rigidity of the airfoil model. The opening of the first groove is provided with a first sinking step to facilitate the lightening cover to sink into the first groove, so that the outer side of the lightening cover adapts to the profile of the upper wing surface of the airfoil body.

[0014] In order to realize the oscillating movement of the airfoil model, a shaft supporting end and a shaft driving end are respectively provided at both ends of the airfoil body, a lightening cover plate close to the shaft driving end is fixedly connected to the airfoil body, and a lightening cover plate close to the shaft supporting end is detachably connected to the airfoil body. In this scheme, in the wind tunnel test, the airfoil body has a rotating shaft arranged at the 1 / 4 chord line, and the two ends are a rotating shaft driving end and a rotating shaft supporting end respectively; wherein, since the rotating shaft driving end is used as the power input position, a cross keyway is arranged on the rotating shaft driving end, which is mainly used for connecting with the dynamic test device, and its functions and components are complicated and not easy to wire, so it is necessary to install components such as wires and sensors at a position close to the rotating shaft supporting end to facilitate the wires to pass through, and the rotating shaft supporting end is used to connect with the tunnel wall supporting device, and is also designed with wiring holes and other interfaces for connecting the test equipment; therefore, the measuring elements can be installed and arranged in the first groove close to the rotating shaft supporting end; in this way, the lightening cover plate close to the rotating shaft supporting end needs to be detachably connected to the airfoil body, such as by bolt connection, so as to facilitate disassembly and replacement; and the lightening cover plate close to the rotating shaft driving end, based on the process conditions, must open the first groove here before processing, so the lightening cover plate here needs to be fixedly connected to the airfoil body, such as by expansion bolts, etc., and is not easy to disassemble.

[0015] To further reduce the mass of the trailing edge of the airfoil body, a trailing edge cover is also included;

[0016] The trailing edge position of the airfoil body is provided with trailing edge notches along both sides of the center plane, and the trailing edge notches penetrate the upper and lower wing surfaces of the airfoil body;

[0017] The trailing edge cover plate is used to be installed in the trailing edge notch and is adapted to the size of the trailing edge notch; the outer side surface of the trailing edge cover plate is adapted to the profile surface of the airfoil main body;

[0018] The trailing edge cover has a chamber inside, and the chamber has a number of staggered third support bars. In this solution, a notch is provided at the trailing edge of the airfoil body to facilitate the installation of the trailing edge cover; and in order to prevent the weight reduction from causing a large deformation in the middle of the model span, notches are provided on both sides of the center plane of the airfoil body; wherein, the trailing edge cover has a chamber inside, and a number of staggered third support bars are distributed in the chamber for support, so that the rigidity and strength of the trailing edge of the airfoil body can be ensured while reducing the weight of the trailing edge of the airfoil body; in addition, since the trailing edge of the airfoil body is a weak area, the material strength of the trailing edge cover itself needs to be greater than the material strength of the airfoil body itself, so as to supplement the trailing edge of the airfoil body; and since the two materials are different, a detachable connection method with a notch is required.

[0019] In order to facilitate the processing of the internal cavity of the trailing edge cover plate and facilitate the detachable installation of the trailing edge cover plate, the trailing edge cover plate includes an upper cover plate located at the upper wing surface and a lower cover plate located at the lower wing surface, the upper cover plate and the lower cover plate can be spliced ​​with each other to form a cavity, and the upper cover plate and the lower cover plate are detachably connected;

[0020] The trailing edge notch has a second sunken step on the circumferential end of the lower wing surface, and the lower cover plate has a protruding end that matches the second sunken step on the circumferential end, and the protruding end and the second sunken step are connected by bolts. In this solution, taking one of the trailing edge cover plates as an example, the trailing edge cover plate is formed by splicing the upper cover plate and the lower cover plate together, so as to facilitate disassembly and separation, and process the internal chamber and the third support strips, wherein several third support strips also divide the internal chamber into honeycomb grooves; the circumferential ends of the upper cover plate and the lower cover plate are connected by bolts, and the circumferential end of the lower cover plate extends outward and has a protruding end, so that after the upper cover plate and the lower cover plate are spliced, the protruding end is placed in the second sunken step to achieve a detachable connection with the airfoil body, thereby forming a completed wing surface.

[0021] In order to obtain the pressure distribution of the airfoil, the airfoil body is provided with pressure measuring hole groups on both sides of the center plane, the pressure measuring hole groups are located between the center plane and the lightening cover plate, and the two pressure measuring hole groups are respectively arranged on the upper wing surface and the lower wing surface of the airfoil body; the orthographic projections of the two pressure measuring hole groups on the wing surface of the airfoil body are symmetrically arranged along the center plane;

[0022] The pressure measuring hole group is arranged obliquely relative to the center plane, and the pressure measuring hole group includes a plurality of pressure measuring holes, which are spaced in sequence from the trailing edge to the leading edge of the airfoil body and gradually move away from the center plane. In this scheme, pressure measuring hole groups are opened on both the upper and lower wing surfaces of the airfoil body to obtain the pressure distribution of the upper and lower wing surfaces of the airfoil; the positive projections of the two pressure measuring hole groups on the wing surface of the airfoil body are symmetrically arranged along the center plane, and the pressure measuring hole groups are arranged obliquely to form a V-shaped distribution, so that the upper and lower pressure measuring hole groups are staggered, so that the density of the pressure measuring holes is increased while reducing the influence between the front and rear pressure measuring holes. In addition, the opening position of the pressure measuring hole group needs to be set near the half span of the airfoil model, so as to minimize the influence of the three-dimensional effect. The pressure measuring hole group includes a plurality of pressure measuring holes arranged in sequence, so that pressure measuring elements are set in the plurality of pressure measuring holes to realize the measurement of aerodynamic data on the wing surface. Among them, the inclination angle of the pressure measuring hole group relative to the center plane is preferably about 10° to 12°.

[0023] In order to improve the measurement accuracy of aerodynamic data, in the pressure measuring hole group, the spacing between adjacent pressure measuring holes decreases in a step-like manner along the direction from the trailing edge to the leading edge of the airfoil body; the number of pressure measuring holes on the upper wing surface is greater than that on the lower wing surface. In this scheme, since the pressure change is more obvious closer to the leading edge area of ​​the airfoil body, the pressure measuring holes are distributed more densely in the leading edge area of ​​the airfoil body, that is, the spacing between adjacent pressure measuring holes gradually decreases from the trailing edge to the leading edge position. In addition, since the pressure change on the upper wing surface is more significant than that on the lower wing surface, the pressure measuring holes on the upper wing surface are more numerous and denser than those on the lower wing surface to improve the measurement accuracy.

[0024] In order to facilitate wiring along the length direction of the pressure measuring hole group, the two pressure measuring hole groups are provided with wiring grooves on the other wing surface facing each other, and the wiring grooves are arranged along the length direction of the pressure measuring hole group on the other wing surface corresponding to the pressure measuring hole group; the wiring grooves are connected to the first groove near the support end of the rotating shaft;

[0025] The opening of the wiring groove is closed with a wiring cover plate, and the outer side surface of the wiring cover plate is adapted to the main body surface of the airfoil. In this scheme, in order to obtain aerodynamic data near the pressure measuring hole sequence, it is necessary to install pressure measuring tubes, pressure pipes, dynamic pressure sensors, signal lines and other testing equipment at the pressure measuring holes and inside the model, so it is necessary to leave wiring and installation interfaces inside the model, that is, a wiring groove is opened on the surface of the model, and the wiring groove is set on the other wing opposite to the pressure measuring hole group, and it is facing the pressure measuring hole group, so that the wiring groove and each pressure measuring hole of the pressure measuring hole group are connected; in addition, because the opened wiring groove will also damage the airfoil surface, it is necessary to use a wiring cover plate to encapsulate and shape the part where the wiring groove is opened, so as to protect and repair the wiring groove.

[0026] In order to facilitate the convergence and arrangement of several wires, along the direction from the trailing edge to the leading edge of the airfoil body, the wiring groove includes interconnected linear grooves and square grooves in sequence, and the square groove is connected to the first groove near the support end of the rotating shaft. In this solution, the wiring groove includes interconnected linear grooves and square grooves in sequence, the linear groove is used for linear arrangement of the pressure pipe, and the square groove is larger in size and is used for the convergence of several circumferential wires, so that the guide is laid out from the square groove and introduced into the first groove.

[0027] In order to arrange pressure measuring holes at the leading edge of the airfoil body, the wiring groove further includes a leading edge notch; one end of the pressure measuring hole group extends to the leading edge of the airfoil body, the leading edge notch is provided on the leading edge of the airfoil body corresponding to one end of the pressure measuring hole group, and the leading edge notch is connected to the inside of the square groove;

[0028] It also includes a leading edge cover plate, the leading edge cover plate is used to close the leading edge gap, and the outer side surface of the leading edge cover plate is matched with the profile surface of the airfoil main body;

[0029] A number of pressure measuring holes at one end of the pressure measuring hole group are provided on the leading edge cover plate. In this scheme, in order to obtain the complete pressure distribution data of the airfoil model, it is necessary to set a number of pressure measuring holes at the leading edge of the airfoil body, so as to measure the aerodynamic data at the leading edge position; in addition, in order to avoid the large deformation of the middle part of the model due to the opening of the wire groove, the leading edge notch and the square groove are isolated from the outside, and the inside is connected for easy wiring; because the leading edge notch will also damage the airfoil profile, it is necessary to use a leading edge cover plate to encapsulate and shape the opened leading edge notch, so as to protect and fill the leading edge notch. The difference between the leading edge cover plate and the wiring cover plate is that the leading edge cover plate can be provided with pressure measuring holes, and form the same group of linearly arranged pressure measuring holes with the corresponding pressure measuring hole group, so as to ensure the number of leading edge pressure measuring holes and improve the accuracy of the test.

[0030] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0031] 1. The present invention provides an airfoil structure for high-frequency dynamic wind tunnel testing. In the high-frequency dynamic wind tunnel testing, the airfoil model shape can be maintained while the mass of the model can be reduced to the maximum extent, thereby greatly reducing the moment of inertia of the model during high-frequency oscillation; and while reducing the mass of the model, the strength and stiffness of the model can be ensured.

[0032] 2. The airfoil structure provided by the present invention for high-frequency dynamic wind tunnel tests can further increase the number of pressure measuring holes while meeting the requirements of strength and stiffness, thereby maximizing the installation effect of the sensor inside the model, reducing the measurement synchronization problem caused by the sensor being installed outside the model, and improving the measurement accuracy of high-frequency dynamic tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0034] Figure 1 A schematic structural diagram of the airfoil structure provided by the present invention;

[0035] Figure 2 A schematic diagram of the upper wing surface structure of the wing-shaped structure provided by the present invention;

[0036] Figure 3 A schematic diagram of the lower wing surface structure of the wing-shaped structure provided by the present invention;

[0037] Figure 4 A schematic diagram of the structure of the rotating shaft driving end provided by the present invention;

[0038] Figure 5 A schematic diagram of the structure of the rotating shaft support end provided by the present invention;

[0039] Figure 6 A schematic diagram of the structure of the upper wing surface of the airfoil body provided by the present invention;

[0040] Figure 7 A schematic diagram of the structure of the lower wing surface of the airfoil body provided by the present invention;

[0041] Figure 8 A schematic diagram of the internal structure of the lightening cover provided by the present invention;

[0042] Fig. 9 A schematic diagram of the internal structure of the upper cover plate provided by the present invention;

[0043] Fig.10 This is a schematic diagram of the internal structure of the lower cover plate provided by the present invention.

[0044] Marks and corresponding parts names in the attached drawings:

[0045] 1-airfoil body, 101-first groove, 102-first support bar, 103-first sinking step, 104-trailing edge notch, 105-second sinking step, 106-linear groove, 107-square groove, 108-leading edge notch, 2-lightening cover plate, 3-wiring cover plate, 4-pressure measuring hole group, 5-rotating shaft support end, 6-trailing edge cover plate, 601-upper cover plate, 602-lower cover plate, 7-rotating shaft drive end, 8-leading edge cover plate. DETAILED DESCRIPTION

[0046] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0047] Embodiment 1: Embodiment 1 provides an airfoil structure for high-frequency dynamic wind tunnel testing, such as Figure 1-Figure 10 As shown, including:

[0048] The airfoil body 1, with the position of one-half of the wingspan of the airfoil body 1 as the center plane, the upper wing surface of the airfoil body 1 is provided with first grooves 101 on both sides of the center plane, and the first grooves 101 are provided with a plurality of staggered first support bars 102;

[0049] The lightening cover plate 2 is used to close the opening of the first groove 101 at the upper wing surface, and the outer side surface of the lightening cover plate 2 is matched with the profile of the airfoil body 1.

[0050] Compared with the prior art, the airfoil wind tunnel tests developed in China are mainly based on static wind tunnel tests and low-frequency dynamic wind tunnel tests, and there is less research on high-frequency dynamic wind tunnel tests of airfoils. In addition, since the test frequency involved in high-frequency dynamic wind tunnel tests is relatively high, the design and processing of the model are required to meet the strength and stiffness requirements while reducing the moment of inertia of the test model. The present invention provides an airfoil structure for high-frequency dynamic wind tunnel tests. By adopting this solution, the strength and stiffness requirements can be met while reducing the moment of inertia of the test model, and it can be effectively applied to high-frequency dynamic wind tunnel tests of airfoils. In the specific scheme, the center plane is a vertical plane from the leading edge to the trailing edge of the airfoil body 1 at the half position of the span of the airfoil body 1; the upper wing surface of the airfoil body 1 is provided with a first groove 101 on both sides of the center plane, and the length direction of the first groove 101 is arranged along the span direction of the airfoil body 1, and the cross-sectional shape of the first groove 101 is preferably a polygonal shape with a wide middle and narrow ends, that is, the two ends gradually shrink and are rounded at the corners to meet the strength conditions of the wing under high-frequency vibration, avoid the main load-bearing positions at the two ends and the middle of the airfoil body 1 without sufficient strength and rigidity, and reserve the installation position of the pressure measuring hole in the middle. The two first grooves 101 are preferably arranged symmetrically along the center plane, and the first grooves 101 can greatly reduce the mass of the airfoil body 1, thereby reducing the rotational inertia of the test model. A plurality of staggered first support bars 102 are distributed in the first groove 101, and the plurality of first support bars 102 are supported in the first groove 101, so as to meet the strength and rigidity requirements required for the experiment through the plurality of first support bars 102; wherein, the plurality of first support bars 102 are staggered, and preferably the first groove 101 is divided into a honeycomb groove, so as to further improve the strength and rigidity. In addition, in order to maintain the shape of the airfoil body 1, a lightening cover plate 2 is also provided at the opening position of the first groove 101, and the lightening cover plate 2 is used to close the first groove 101 and is adapted to the profile of the wing surface on the airfoil body 1. The above scheme can reduce the mass of the model to the maximum extent while maintaining the shape of the airfoil model in the high-frequency dynamic wind tunnel test, and greatly reduce the moment of inertia of the model during high-frequency oscillation; and through the plurality of first support bars 102 designed internally, the strength and rigidity of the model are ensured.

[0051] like Figure 6 and 8 As shown, in order to further reduce the mass of the model, the inner side surface of the lightening cover plate 2 is provided with a second groove adapted to the first groove 101, and the second groove is provided with a plurality of staggered second support bars, and the second support bars correspond to the first support bars 102 one by one;

[0052] The opening of the first groove 101 is provided with a first sinking step 103, and the circumferential end of the lightening cover plate 2 is used to be placed in the first sinking step 103 and bolted to the first sinking step 103. In this solution, the lightening cover plate 2 needs to have a certain thickness, and a second groove is provided on the inner side of the lightening cover plate 2, so that after the lightening cover plate 2 is installed on the upper wing surface of the airfoil body 1, the mass of the airfoil model is further reduced; a number of staggered second support bars are provided in the second groove, and when the lightening cover plate 2 is installed on the airfoil body 1, the second support bars and the second support bars are supported one by one, thereby further ensuring the strength and rigidity of the airfoil model. The opening of the first groove 101 is provided with a first sinking step 103, so that the lightening cover plate 2 can sink into the first groove 101, so that the outer side of the lightening cover plate 2 can adapt to the profile of the upper wing surface of the airfoil body 1.

[0053] In order to realize the oscillating motion of the airfoil model, the two ends of the airfoil body 1 are respectively provided with a shaft support end 5 and a shaft drive end 7. The lightening cover plate 2 near the shaft drive end 7 is fixedly connected to the airfoil body 1, and the lightening cover plate 2 near the shaft support end 5 is detachably connected to the airfoil body 1. In this scheme, in the wind tunnel experiment, the airfoil body 1 has its shaft set at the 1 / 4 chord line, and its two ends are respectively a shaft drive end 7 and a shaft support end 5; wherein, since the shaft drive end 7 is used as the power input position, a cross keyway is provided on the shaft drive end 7, which is mainly used for connection with the dynamic test device. Its functions and components are complicated and not easy to wire. Therefore, it is necessary to install components such as wires and sensors near the shaft support end 5 to facilitate the wires to pass through. The shaft support end 5 is used to connect with the tunnel wall support device, and is also designed with wiring holes and other interfaces, so as to use for connecting the test equipment; therefore, the measuring elements can be installed and arranged in the first groove 101 near the shaft support end 5; in this way, the lightening cover plate 2 near the shaft support end 5 needs to be detachably connected to the airfoil body 1, such as by bolts, to facilitate disassembly and replacement; and the lightening cover plate 2 near the shaft drive end 7, based on process conditions, must have a first groove 101 opened here before processing can be carried out, so the lightening cover plate 2 here needs to be fixedly connected to the airfoil body 1, such as by expansion bolts, etc., and is not easy to disassemble.

[0054] Embodiment 2: Embodiment 2 is further defined on the basis of Embodiment 1, and provides a specific arrangement method of the trailing edge notch 104 and the trailing edge cover plate 6 on the airfoil body 1.

[0055] In order to further reduce the mass of the trailing edge of the airfoil body 1, a trailing edge cover plate 6 is also included;

[0056] The trailing edge position of the airfoil body 1 is provided with trailing edge notches 104 along both sides of the center plane, and the trailing edge notches 104 penetrate the upper and lower airfoils of the airfoil body 1;

[0057] The trailing edge cover plate 6 is used to be installed in the trailing edge notch 104 and is adapted to the size of the trailing edge notch 104; the outer side surface of the trailing edge cover plate 6 is adapted to the profile surface of the airfoil body 1;

[0058] The trailing edge cover plate 6 has a chamber inside, and the chamber has a number of staggered third support bars. In this solution, a notch is provided at the trailing edge of the airfoil body 1 to facilitate the installation of the trailing edge cover plate 6; and in order to prevent the weight reduction from causing a large deformation in the middle of the model span, notches are provided on both sides of the center plane of the airfoil body 1; wherein, the trailing edge cover plate 6 has a chamber inside, and a number of staggered third support bars are distributed in the chamber for support, so that the rigidity and strength of the trailing edge of the airfoil body 1 can be ensured while reducing the weight of the trailing edge of the airfoil body 1; in addition, since the trailing edge of the airfoil body 1 is a weak area, the material strength of the trailing edge cover plate 6 itself needs to be greater than the material strength of the airfoil body 1 itself, so as to supplement the trailing edge of the airfoil body 1; and since the two materials are different, a detachable method of opening a notch is required for connection.

[0059] In order to facilitate the processing of the internal cavity of the trailing edge cover plate 6 and facilitate the detachable installation of the trailing edge cover plate 6, the trailing edge cover plate 6 includes an upper cover plate 601 located at the upper wing surface and a lower cover plate 602 located at the lower wing surface. The upper cover plate 601 and the lower cover plate 602 can be spliced ​​with each other to form a cavity, and the upper cover plate 601 and the lower cover plate 602 are detachably connected;

[0060] The trailing edge notch 104 has a second sinking step 105 on the circumferential end of the lower wing surface, and the lower cover plate 602 has a protruding end adapted to the second sinking step 105 on the circumferential end, and the protruding end is connected to the second sinking step 105 by bolts. In this solution, taking one of the trailing edge cover plates 6 as an example, the trailing edge cover plate 6 is formed by the upper cover plate 601 and the lower cover plate 602 being joined together to facilitate disassembly and separation, and processing the internal chamber and the third support strips, wherein several third support strips also divide the internal chamber into honeycomb grooves; the circumferential ends of the upper cover plate 601 and the lower cover plate 602 are connected by bolts, and the circumferential end of the lower cover plate 602 extends outward and has a protruding end, so that after the upper cover plate 601 and the lower cover plate 602 are spliced, the protruding end is placed in the second sinking step 105 to achieve a detachable connection with the airfoil body 1, thereby forming a completed wing surface.

[0061] Embodiment 3: Embodiment 3 is further limited on the basis of Embodiment 1 or Embodiment 2, and provides a specific distribution method of pressure measuring holes.

[0062] In order to obtain the pressure distribution of the airfoil, the airfoil body 1 is provided with pressure measuring hole groups 4 on both sides of the center plane, the pressure measuring hole groups 4 are located between the center plane and the lightening cover plate 2, and the two pressure measuring hole groups 4 are respectively arranged on the upper wing surface and the lower wing surface of the airfoil body 1; the orthographic projections of the two pressure measuring hole groups 4 on the wing surface of the airfoil body 1 are symmetrically arranged along the center plane;

[0063] The pressure measuring hole group 4 is tilted relative to the center plane, and the pressure measuring hole group 4 includes a plurality of pressure measuring holes, which are spaced in sequence from the trailing edge to the leading edge of the airfoil body 1 and gradually move away from the center plane. In this scheme, a pressure measuring hole group 4 is provided on both the upper and lower wing surfaces of the airfoil body 1 to facilitate obtaining the pressure distribution of the upper and lower wing surfaces of the airfoil; the positive projections of the two pressure measuring hole groups 4 on the wing surface of the airfoil body 1 are symmetrically arranged along the center plane, and the pressure measuring hole group 4 is tilted to form a V-shaped distribution, so that the upper and lower pressure measuring hole groups 4 are staggered, so that the density of the pressure measuring holes is increased while reducing the influence between the front and rear pressure measuring holes. In addition, the opening position of the pressure measuring hole group 4 needs to be set near the half span of the airfoil model, so as to minimize the influence of the three-dimensional effect. The pressure measuring hole group 4 includes a plurality of pressure measuring holes arranged in sequence, so that pressure measuring elements can be set in the plurality of pressure measuring holes to achieve the measurement of aerodynamic data on the wing surface. The inclination angle of the pressure measuring hole group 4 relative to the center plane is preferably about 10° to 12°.

[0064] In order to improve the measurement accuracy of aerodynamic data, in the pressure measuring hole group 4, the spacing between adjacent pressure measuring holes decreases in a step-like manner along the direction from the trailing edge to the leading edge of the airfoil body 1; the number of pressure measuring holes on the upper wing surface is greater than the number of pressure measuring holes on the lower wing surface. In this solution, since the pressure change is more obvious closer to the leading edge area of ​​the airfoil body 1, the pressure measuring holes are distributed more densely in the leading edge area of ​​the airfoil body 1, that is, the spacing between adjacent pressure measuring holes gradually decreases from the trailing edge to the leading edge position. In addition, since the pressure change on the upper wing surface is more significant than that on the lower wing surface, the pressure measuring holes on the upper wing surface are more numerous and denser than those on the lower wing surface to improve the measurement accuracy.

[0065] In order to facilitate wiring along the length direction of the pressure measuring hole group 4, the two pressure measuring hole groups 4 are provided with wiring grooves on the other wing surface facing each other, and the wiring grooves are arranged along the length direction of the pressure measuring hole group 4 on the other wing surface corresponding to the pressure measuring hole group 4; the wiring grooves are connected to the first groove 101 close to the shaft support end 5;

[0066] The opening of the wiring groove is closed with a wiring cover plate 3, and the outer side surface of the wiring cover plate 3 is adapted to the profile of the airfoil body 1. In this scheme, in order to obtain aerodynamic data near the pressure measuring hole sequence, it is necessary to install pressure measuring tubes, pressure pipes, dynamic pressure sensors, signal lines and other testing equipment at the pressure measuring holes and inside the model, so it is necessary to leave wiring and installation interfaces inside the model, that is, a wiring groove is opened on the surface of the model, and the wiring groove is set on the other airfoil opposite to the pressure measuring hole group 4, and it is facing the pressure measuring hole group 4, so that the wiring groove and each pressure measuring hole of the pressure measuring hole group 4 are connected; in addition, since the opened wiring groove will also damage the airfoil profile, it is necessary to use a wiring cover plate 3 to encapsulate and shape the part where the wiring groove is opened, so as to protect and repair the wiring groove.

[0067] In order to facilitate the convergence and arrangement of several wires, the wiring groove includes a connected linear groove 106 and a square groove 107 in sequence along the direction from the trailing edge to the leading edge of the airfoil body 1, and the square groove 107 is connected to the first groove 101 near the rotating shaft support end 5. In this solution, the wiring groove includes a connected linear groove 106 and a square groove 107 in sequence, the linear groove 106 is used for linear arrangement of the pressure pipe, and the square groove 107 is larger in size and is used for the convergence of several circumferential wires, so that the guide is laid out from the square groove 107 and introduced into the first groove 101.

[0068] In order to arrange the pressure measuring holes at the leading edge of the airfoil body 1, the wiring groove further includes a leading edge notch 108; one end of the pressure measuring hole group 4 extends to the leading edge of the airfoil body 1, and the leading edge notch 108 is provided on the leading edge of the airfoil body 1 corresponding to one end of the pressure measuring hole group 4, and the leading edge notch 108 is connected to the inside of the square groove 107;

[0069] It also includes a leading edge cover plate 8, the leading edge cover plate 8 is used to close the leading edge notch 108, and the outer side surface of the leading edge cover plate 8 is matched with the profile of the airfoil body 1;

[0070] Several pressure measuring holes at one end of the pressure measuring hole group 4 are provided on the leading edge cover plate 8. In this scheme, in order to obtain the complete pressure distribution data of the airfoil model, it is necessary to set several pressure measuring holes at the leading edge position of the airfoil body 1, so as to measure the aerodynamic data at the leading edge position; in addition, in order to avoid the large deformation of the middle part of the model due to the opening of the wire groove, the leading edge notch 108 and the square groove 107 are isolated from the outside, and connected internally for easy wiring; because the leading edge notch 108 will also damage the airfoil profile, it is necessary to use the leading edge cover plate 8 to encapsulate and shape the opened leading edge notch 108, so as to protect and repair the leading edge notch 108. The difference between the leading edge cover plate 8 and the wiring cover plate 3 is that the leading edge cover plate 8 can be provided with pressure measuring holes, and form the same group of linearly arranged pressure measuring holes with the corresponding pressure measuring hole group 4, so as to ensure the number of leading edge pressure measuring holes and improve the accuracy of the test.

[0071] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An airfoil structure for high-frequency dynamic wind tunnel testing, characterized in that: include: An airfoil body (1), with the position of one-half of the wingspan of the airfoil body (1) as the center plane, the upper wing surface of the airfoil body (1) having first grooves (101) on both sides of the center plane, and the first grooves (101) having a plurality of staggered first support bars (102); A lightening cover plate (2), the lightening cover plate (2) being used to close the opening of the first groove (101) at the upper wing surface, and the outer side surface of the lightening cover plate (2) is adapted to the profile of the wing body (1); The two ends of the airfoil body (1) are respectively provided with a rotating shaft support end (5) and a rotating shaft drive end (7); the lightening cover plate (2) close to the rotating shaft drive end (7) is fixedly connected to the airfoil body (1); and the lightening cover plate (2) close to the rotating shaft support end (5) is detachably connected to the airfoil body (1); The airfoil body (1) is provided with pressure measuring hole groups (4) on both sides along the center plane, the pressure measuring hole groups (4) are located between the center plane and the lightening cover plate (2), and two pressure measuring hole groups (4) are respectively arranged on the upper wing surface and the lower wing surface of the airfoil body (1); the orthographic projections of the two pressure measuring hole groups on the wing surface of the airfoil body (1) are symmetrically arranged along the center plane; The pressure measuring hole group is arranged obliquely relative to the center plane, the pressure measuring hole group (4) comprises a plurality of pressure measuring holes, and the plurality of pressure measuring holes are distributed in sequence at intervals from the trailing edge to the leading edge of the airfoil body (1) and gradually move away from the center plane; The two pressure measuring hole groups (4) are each provided with a wiring groove on the other wing surface facing each other, and the wiring groove is arranged along the length direction of the pressure measuring hole group (4) on the other wing surface corresponding to the pressure measuring hole group (4); the wiring groove is connected to the first groove (101) close to the support end (5) of the rotating shaft; The opening of the wiring groove is sealed with a wiring cover plate (3), and the outer side surface of the wiring cover plate (3) is matched with the profile of the airfoil body (1).

2. The airfoil structure for high-frequency dynamic wind tunnel testing according to claim 1, characterized in that: The inner side surface of the lightening cover plate (2) is provided with a second groove matched with the first groove (101), the second groove is provided with a plurality of second support bars distributed in an alternating manner, and the second support bars correspond to the first support bars (102) one by one; The opening of the first groove (101) is provided with a first sunken step (103), and the circumferential end of the lightening cover plate (2) is used to be placed in the first sunken step (103) and is bolted to the first sunken step (103).

3. The airfoil structure for high-frequency dynamic wind tunnel testing according to claim 1, characterized in that: Also includes a trailing edge cover plate (6); A trailing edge notch (104) is provided at the trailing edge of the airfoil body (1) along both sides of the center plane, and the trailing edge notch (104) passes through the upper and lower airfoils of the airfoil body (1); The trailing edge cover plate (6) is used to be installed in the trailing edge notch (104) and is adapted to the size of the trailing edge notch (104); the outer side surface of the trailing edge cover plate (6) is adapted to the profile of the airfoil body (1); The rear edge cover plate (6) has a chamber inside, and the chamber has a plurality of third struts distributed in a staggered manner.

4. The airfoil structure for high-frequency dynamic wind tunnel testing according to claim 3, characterized in that: The trailing edge cover plate (6) comprises an upper cover plate (601) located at the upper wing surface and a lower cover plate (602) located at the lower wing surface, the upper cover plate (601) and the lower cover plate (602) can be spliced ​​together to form a chamber, and the upper cover plate (601) and the lower cover plate (602) are detachably connected; The trailing edge notch (104) has a second sunken step (105) at the circumferential end of the lower wing surface, and the lower cover plate (602) has a protruding end that matches the second sunken step (105) at the circumferential end, and the protruding end and the second sunken step (105) are connected by bolts.

5. The airfoil structure for high-frequency dynamic wind tunnel testing according to claim 1, characterized in that: In the pressure measuring hole group (4), the spacing between adjacent pressure measuring holes decreases in a step-like manner along the direction from the trailing edge to the leading edge of the airfoil body (1); The number of pressure measuring holes on the upper wing surface is greater than the number of pressure measuring holes on the lower wing surface.

6. The airfoil structure for high-frequency dynamic wind tunnel testing according to claim 1, characterized in that: Along the direction from the trailing edge to the leading edge of the airfoil body (1), the wiring groove comprises a linear groove (106) and a square groove (107) in sequence, and the square groove (107) is connected to the first groove (101) close to the rotating shaft support end (5).

7. The airfoil structure for high-frequency dynamic wind tunnel testing according to claim 6, characterized in that: The wiring trough further includes a front edge notch (108); One end of the pressure measuring hole group (4) extends to the leading edge of the airfoil body (1), the leading edge notch (108) is provided on the leading edge of the airfoil body (1) corresponding to one end of the pressure measuring hole group (4), and the leading edge notch (108) is connected to the inside of the square groove (107); It also comprises a leading edge cover plate (8), the leading edge cover plate (8) being used to close the leading edge notch (108), and the outer side surface of the leading edge cover plate (8) is matched with the profile surface of the airfoil body (1); A plurality of pressure measuring holes at one end of the pressure measuring hole group (4) are provided on the leading edge cover plate (8).

Images