Noise control device and vehicle

Abstract

The application discloses a noise control device and a vehicle, and relates to the technical field of aerospace. The vehicle comprises a first cavity and a second cavity. The noise control device comprises a first spoiler. The first spoiler is located on the side of the first cavity far from the second cavity and has an included angle with the plane where the first cavity is located. The first spoiler has a first free end and a first fixed end which are away from each other. The first fixed end is connected to the edge of the first cavity. The first free end is provided with a square tooth structure. The application controls the noise intensity by adopting the square tooth structure. The first spoiler is provided with the square tooth structure and is located on the side of the first cavity far from the second cavity. The fluid flows in the direction from the first cavity to the second cavity. In the experiment, it can be known that the first spoiler provided with the square tooth structure has a better noise reduction effect than other structures, which can improve the noise reduction effect for the tandem cavity structure.

Description

Technical Field

[0001] This application relates to the field of aerospace technology, and in particular to a noise control device and an aircraft. Background Technology

[0002] Aircraft fuselages or wings contain hollow structures, such as landing gear bays, which house and protect the landing gear and its piping. When fluid flows through these hollow structures (such as landing gear bays or vents under the wings), it generates strong aerodynamic effects, producing high-intensity pulsating pressure and far-field noise. Existing aircraft commonly employ noise control devices and methods to reduce the impact of noise on the aircraft's structural strength and lifespan.

[0003] Existing technologies have focused on noise control for individual cavities, but in practical applications, the number of cavities is much greater, and multiple cavities are often connected in series, making the noise generation mechanism and control measures more complex. Traditional passive control methods (such as leading-edge turbulence and rear wall chamfering) are effective in single cavities, but their noise reduction effect is poor for series cavity systems, and the noise reduction magnitude is not ideal. Summary of the Invention

[0004] The purpose of this application is to provide a noise control device and a vehicle to alleviate or solve the aforementioned technical problems existing in the prior art.

[0005] In a first aspect, this application provides a noise control device for reducing the noise of an aircraft. The aircraft includes a first cavity and a second cavity. The noise control device includes a first spoiler. The first spoiler is located on the side of the first cavity away from the second cavity and has an angle with the plane in which the first cavity is located. The first spoiler has a first free end and a first fixed end that are far apart from each other. The first fixed end is connected to the edge of the first cavity, and the first free end is provided with a square tooth structure.

[0006] Secondly, this application provides a vehicle that includes a noise control device as described in the first aspect. The vehicle includes a first cavity and a second cavity, and a first fixed end is disposed at the edge of the first cavity.

[0007] The technical solution adopted in this application can achieve the following beneficial effects: the first baffle is disposed at the edge of the first cavity, and the fluid flows in the direction from the first cavity to the second cavity. The fluid flows through the first baffle, and the end of the first baffle away from the first cavity is provided with a square tooth structure. The first baffle can significantly improve the control effect on the incoming flow, thereby reducing noise in the cavity.

[0008] Compared to existing technologies, this application controls noise intensity by employing a square tooth structure. The first baffle has a square tooth structure and is positioned on the side of the first cavity away from the second cavity. Furthermore, the fluid flows along the direction from the first cavity to the second cavity. Experiments show that the first baffle with the square tooth structure can achieve a noise reduction of up to 46 dB, which is superior to other structures (such as sawtooth structures), thus improving noise reduction for tandem cavity structures. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 This is a schematic diagram of the structure of an aircraft shown in an exemplary embodiment of this application; Figure 2 This is a schematic diagram of the structure of an aircraft from another perspective, illustrating an exemplary embodiment of this application; Figure 3 This is an exemplary embodiment of the present application, showing the noise spectrum characteristic curve of a triangular tooth. Figure 4 This is an exemplary embodiment of the present application, showing the noise spectrum characteristics of square teeth; Figure 5 This is a schematic diagram of the structure of a vehicle shown in another exemplary embodiment of this application; Figure 6 This is a schematic diagram of the structure of a vehicle from another perspective, illustrating another exemplary embodiment of this application; Figure 7 This is a schematic diagram of the triangular tooth structure shown in an exemplary embodiment of this application; Figure 8 This is a schematic diagram of a square tooth structure shown in an exemplary embodiment of this application; Figure 9 This is a schematic diagram of the structure of a vehicle shown in yet another exemplary embodiment of this application; Figure 10 This is a schematic diagram of the structure of a vehicle shown in yet another exemplary embodiment of this application.

[0011] In the diagram: 100, aircraft; 110, noise control device; 111, first spoiler; 1111, first free end; 1112, first fixed end; 1113, square tooth structure; 1114, sub-square block; 112, second spoiler; 1121, second free end; 1122, second fixed end; 1123, triangular tooth structure; 1124, sub-triangular block; 120, first cavity; 130, second cavity. Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0013] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0014] This application provides a noise control device 110; please refer to [link / reference]. Figure 1 The noise control device 110 is used to reduce the noise of the vehicle 100. The vehicle 100 includes, but is not limited to, aircraft, ships, and underwater vehicles; the following description uses an aircraft as an example. The vehicle 100 may include a first cavity 120 and a second cavity 130, which may be formed in the aircraft's landing gear bay, under-wing ventilation openings, etc., without specific limitations. The vehicle 100 has a first surface, and the first cavity 120 and the second cavity 130 are formed on the first surface of the vehicle 100.

[0015] Please see Figure 1 and Figure 2The noise control device 110 may include a first baffle 111. The first baffle 111 is located on the side of the first cavity 120 away from the second cavity 130 and forms an angle with the plane of the first cavity 120. The first baffle 111 has a first free end 1111 and a first fixed end 1112 that are far apart from each other. The first fixed end 1112 is connected to the edge of the first cavity 120. The first free end 1111 is provided with a square tooth structure 1113. Fluid flows through the first baffle 111, and the end of the first baffle 111 away from the first cavity 120 is provided with the square tooth structure 1113. The first baffle 111 can significantly improve the control effect on the incoming flow, thereby reducing the noise in the cavity.

[0016] This application controls noise intensity by employing a square tooth structure 1113. The first baffle 111 is provided with the square tooth structure 1113 and is located on the side of the first cavity 120 away from the second cavity 130. Furthermore, fluid flows along the direction from the first cavity 120 to the second cavity 130. Experiments show that the first baffle 111 with the square tooth structure 1113 can achieve a noise reduction of up to 46 dB, which is better than other structures (such as sawtooth structures), thus improving the noise reduction effect for tandem cavity structures.

[0017] In implementing this application, the applicant conducted comparative experiments on passive control measures involving triangular and square teeth tilted at different angles along the flow direction at the leading edge of the cavity, as follows: The experimental model is a tandem cavity structure with two cavities arranged along the flow direction. The cavity material is acrylic sheet, and the experimental support platform is aluminum plate. Specifically, the tandem cavity structure has a first cavity 120 and a second cavity 130. Relative to the direction of the fluid, the first cavity 120 is located upstream of the second cavity 130. The basic dimensions of the first cavity 120 and the second cavity 130 are: 160mm (length) × 240mm (width) × 80mm (depth). The distance between the first cavity 120 and the second cavity 130 is 320mm, and the fluid velocity in the experiment is 80m / s.

[0018] Figure 3 This is a noise spectrum characteristic curve after taking a triangular toothed sample. The sampling point for this noise spectrum characteristic is directly above the trailing edge of the first cavity 120 when the fluid velocity is 80 m / s. Figure 3It can be seen that the amplitude of the dominant frequency mode is 99dB without any control measures. After installing 30°, 45°, 60°, and 90° triangular teeth on the leading edge of the first cavity 120, the amplitude decreased by 20dB, 33dB, 23dB, and 24dB, respectively. After installing 30°, 45°, 60°, and 90° triangular teeth on the leading edge of the second cavity 130, the amplitude decreased by 37dB, 40dB, 8dB, and 41dB, respectively. This indicates that among the triangular teeth, installing 90° triangular teeth on the leading edge of the second cavity 130 has the best noise reduction effect.

[0019] Figure 4 This is a noise spectrum characteristic curve after the square teeth are taken. The sampling point for this noise spectrum characteristic is directly above the trailing edge of the first cavity 120 when the fluid velocity is 80 m / s. Figure 4 It can be seen that the amplitude of the dominant frequency mode is 99dB without any control measures. After installing 45°, 60°, and 90° square teeth on the leading edge of the first cavity 120, the amplitude is reduced by 46dB, 44dB, and 43dB, respectively. After installing 45°, 60°, and 90° square teeth on the leading edge of the second cavity 130, the amplitude is reduced by 41dB, 43dB, and 8dB, respectively. This indicates that among the square teeth, installing 45° square teeth on the leading edge of the first cavity 120 has the best noise reduction effect.

[0020] The leading edge of the first cavity 120 refers to the edge of the first cavity 120 closest to the direction of fluid flow, that is, the edge of the first cavity 120 furthest from the second cavity 130. Conversely, the trailing edge of the first cavity 120 refers to the edge of the first cavity 120 furthest from the direction of fluid flow. Similarly, the leading edge of the second cavity 130 refers to the edge of the second cavity 130 closest to the direction of fluid flow, that is, the edge of the second cavity 130 closest to the first cavity 120. Conversely, the trailing edge of the second cavity 130 refers to the edge of the second cavity 130 furthest from the direction of fluid flow.

[0021] In summary, based on the effectiveness of eliminating noise in the first cavity 120 and the second cavity 130, the scheme of installing square teeth at the leading edge of the first cavity 120 is superior to the scheme of installing triangular teeth.

[0022] In the embodiments of this application, please refer to Figure 2Along the direction from the first cavity 120 to the second cavity 130, there is an angle α between the plane where the first baffle 111 and the first cavity 120 are located. The angle α is greater than or equal to 30° and less than or equal to 90°, such as 30°, 45°, 60°, or 90°, and is not limited. The angle should not be too small or too large. If the angle is too small, the first baffle 111 is close to the plane where the first cavity 120 is located, and the guiding and turbulent ability of the first baffle 111 on the incoming airflow is greatly weakened, and its noise reduction effect is reduced. If the angle is too large, when the fluid flows through the first baffle 111, it will form a large number of disordered small vortices on the back of the baffle, and the first baffle 111 will also be excessively windward. These broken vortices will not only significantly increase the pressure drag, but also generate strong turbulent noise. When the included angle is appropriate, the first baffle 111 can orderly flow around and separate the incoming flow along the contour of the square tooth structure 1113, effectively controlling the fluid conditions. This also allows the airflow impact load borne by the first baffle 111 to be evenly distributed, avoiding the first baffle 111 from being overly exposed to the wind and bearing the impact force.

[0023] In the embodiments of this application, please refer to Figure 5 The noise control device 110 may further include a second baffle 112, which is located on the side of the second cavity 130 closer to the first cavity 120. The second baffle 112 and the plane containing the second cavity 130 form an angle. The first baffle 111 and the second baffle 112 may be parallel or non-parallel, without restriction. The second baffle 112 has a second free end 1121 and a second fixed end 1122 that are far apart from each other. The second fixed end 1122 is connected to the edge of the second cavity 130, and the second free end 1121 is provided with a triangular tooth structure 1123. Because the first cavity 120 is located on the side of the second cavity 130 closer to the incoming flow, the first baffle 111 can preferentially contact the fluid compared to the second baffle 112. The square tooth structure 1113 of the first baffle 111 can uniformly cut large-scale vortices, reducing the risk of multi-cavity coupled resonance. Facing the upstream uneven wake and residual vortices, the triangular tooth structure 1123 of the second spoiler 112 can break up locally concentrated vortices and disperse the natural vibration frequency of the downstream cavity with asymmetric disturbance. The square tooth structure 1113 and the triangular tooth structure complement each other to achieve efficient noise reduction across the entire flow field. Relatively speaking, the combination of the first spoiler 111 and the second spoiler 112 in this application can reduce the noise generated by resonance.

[0024] Please see Figure 6Along the direction from the first cavity 120 to the second cavity 130, the planes where the second baffle 112 and the second cavity 130 are located have an included angle β. The included angle β is greater than or equal to 30° and less than or equal to 90°, such as 30°, 45°, 60°, or 90°, and is not limited. The included angle should not be too small or too large. If the included angle is too small, the guiding and turbulence capabilities of the second baffle 112 on the incoming airflow are greatly weakened, and its noise reduction effect is reduced. If the included angle is too large, when the fluid flows through the second baffle 112, it will form a large number of disordered small vortices on the back of the baffle, and the second baffle 112 will also be excessively windward. When the included angle is appropriate, the second baffle 112 can accept the fluid from the square tooth structure 1113 and effectively control the fluid conditions.

[0025] For a better option, please continue reading. Figure 6 The included angle α can be 45°, and the included angle β can be 90°. In other words, the first spoiler 111 is disposed on the side of the first cavity 120 away from the second cavity 130, and the included angle between the first spoiler 111 and the surface of the first cavity 120 is 45°. The second spoiler 112 is disposed on the side of the second cavity 130 close to the first cavity 120, and the included angle between the first spoiler 111 and the surface of the first cavity 120 is 90°. The airflow can be smoothly split along the surface of the first spoiler 111 and generate a large-scale, low-frequency stable vortex system. This vortex system can effectively cover the opening of the first cavity 120, suppress the backflow of airflow in the cavity, and at the same time slowly diffuse towards the second cavity 130, providing a buffer for the airflow transition between the two cavities. The triangular tooth structure 1123 is perpendicular to the incoming flow direction, which can maximally sever the incoming flow boundary layer to suppress pressure resonance within the second cavity 130 and cancel out the large-scale vortex system diffused from the first cavity 120, weakening the airflow coupling disturbance between adjacent cavities and avoiding the superposition and amplification of resonance noise. Furthermore, as mentioned above, among the triangular teeth, installing 90° triangular teeth at the leading edge of the second cavity 130 provides the best noise reduction effect. Among the square teeth, installing 45° square teeth at the leading edge of the first cavity 120 provides the best noise reduction effect. Simultaneously, by installing both square and triangular teeth, this can further eliminate noise from tandem cavities and prevent mutual interference between multiple cavities in a tandem configuration.

[0026] In one implementation, please refer to Figure 7The triangular tooth structure 1123 may include sub-triangular blocks 1124, and the number of sub-triangular blocks 1124 may be multiple, such as 2, 3, or even more, without limitation. Preferably, the sub-triangular blocks 1124 may be equilateral triangles. Multiple sub-triangular blocks 1124 are distributed sequentially along the second free end 1121. Compared to the turbulence caused by a single triangular block, when the fluid flows through the triangular tooth structure 1123, the fluid can form small-scale vortices at each sub-triangular block 1124, which avoids turbulent noise caused by excessively high energy in local vortices. Simultaneously, the turbulence effect of multiple sub-triangular blocks 1124 can extend the stable propagation distance of the vortex system and suppress airflow backflow and pressure resonance within the second cavity 130. Furthermore, adjacent sub-triangular blocks 1124 are connected, which can prevent additional vortex losses in the airflow at the gaps between the teeth, thereby improving aerodynamic efficiency.

[0027] In the embodiments of this application, please refer to Figure 8 The square tooth structure 1113 may include sub-square blocks 1114, each with the same side length and width. The number of sub-square blocks 1114 can be multiple, such as two, three, or even more, without limitation. These multiple sub-square blocks 1114 are evenly spaced along the first free end 1111. This can break the incoming flow boundary layer into small-scale vortices of uniform size, preventing the localized generation of large-scale vortices. Simultaneously, this weakens the flow coupling effect between the baffle and the incoming flow, suppresses local resonance caused by uneven disturbance, and provides stable inflow conditions for the second cavity 130 and its corresponding second baffle 112, improving noise reduction stability.

[0028] In the embodiments of this application, please refer to Figure 9 The number of second cavities 130 can be at least two, such as two, three, or even more, without limitation. At least two second cavities 130 are distributed sequentially at intervals to meet implementation scenarios and requirements, without limitation. The number of second baffles 112 can be at least two, with each second baffle 112 corresponding to a second cavity 130, and one second baffle 112 corresponding to the leading edge of each second cavity 130. While the fluid flows through the first baffle 111, the first baffle 111 can generate a large-scale stable vortex system, suppressing backflow within its own cavity while providing a buffer for airflow regulation in the downstream second cavity 130. The 90° triangular tooth structure 1123 at the leading edge of each second cavity 130 regulates the buffered airflow, generating a small-scale, high-intensity vortex system, further suppressing pressure resonance in the downstream cavity. This maximizes the complementary effect of the vortex systems and avoids the superposition of vortex resonance.

[0029] In this embodiment, the noise control device 110 is provided with a base frame, and the first spoiler 111 and the second spoiler 112 are disposed on the base frame. The base frame is used to be installed on the surface of the aircraft 100 and is correspondingly disposed with the first cavity 120 and the second cavity 130. Preferably, the edges of the first cavity 120 and the second cavity 130 are provided with grooves, and the base frame can be installed and hidden in the grooves to avoid the base frame disturbing the airflow and affecting the noise reduction effect. The base frame can be a hollow structure, a sheet structure, etc., and is not limited. For example, the first spoiler 111 and the second spoiler 112 are rotatably disposed on the base frame, and the base frame is provided with a locking structure. The locking structure can be a limiting block, which abuts between the first spoiler 111 and the base frame and between the second spoiler 112 and the base frame, so that the first spoiler 111 and the second spoiler 112 can be fixed in the corresponding positions. This prevents angular misalignment of the first spoiler 111 and the second spoiler 112, avoiding disturbances in the size, frequency, and propagation direction of the vortex system. Such disturbances would not only fail to achieve the desired noise reduction and flow stabilization effect but could also cause additional aerodynamic drag and noise due to vortex distortion. The base frame serves as the carrier for the first spoiler 111 and the second spoiler 112; simply installing them in their corresponding positions simplifies the installation process of the noise control device 110 and improves installation efficiency.

[0030] This application also provides an aircraft 100, please refer to... Figure 1 The aircraft 100 may include the noise control device 110 as described above, thus enabling the aircraft 100 to possess the beneficial effects of any of the aforementioned solutions, which will not be elaborated further here. The aircraft 100 may include a first cavity 120 and a second cavity 130, with a first fixed end 1112 disposed at the edge connecting to the first cavity 120. Furthermore, in one case, the number of second cavities 130 is at least two, such as two, three, or even more. At least two second cavities 130 are sequentially spaced to meet implementation scenarios and requirements, and are not limited thereto.

[0031] Within a single cavity, the inflow and outflow create a strong shearing effect, breaking large-scale turbulent vortices into smaller ones. The energy of these smaller vortices is rapidly dissipated through fluid viscosity, thus reducing the noise generated by the airflow impacting the cavity walls. In one embodiment, please refer to... Figure 10 In this application, the distance ΔL between the first cavity 120 and the second cavity 130 is greater than the length L1 of the first cavity 120. This arrangement can eliminate the backflow phenomenon in the first cavity 120, cut off the vortex coupling effect between adjacent cavities, and effectively avoid the superposition of resonance noise between the first cavity 120 and the second cavity 130, thereby controlling the noise cancellation effect.

[0032] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0033] Furthermore, it should be noted that the scope of the methods and apparatus in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. In addition, features described with reference to certain examples may be combined in other examples.

[0034] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A noise control device for reducing the noise of an aircraft, characterized in that, The vehicle includes a first cavity and a second cavity, and the noise control device includes a first spoiler, which is located on the side of the first cavity away from the second cavity and has an angle with the plane in which the first cavity is located. The first baffle has a first free end and a first fixed end that are far apart from each other. The first fixed end is connected to the edge of the first cavity, and the first free end is provided with a square tooth structure.

2. The noise control device according to claim 1, characterized in that, The noise control device further includes a second baffle plate, which is located on the side of the second cavity closer to the first cavity and has an angle with the plane where the second cavity is located. The second baffle plate has a second free end and a second fixed end that are far apart from each other. The second fixed end is connected to the edge of the second cavity, and the second free end is provided with a triangular tooth structure. And / or, along the direction from the first cavity to the second cavity, there is an angle α between the plane where the first baffle and the first cavity are located, the angle α being greater than or equal to 30° and less than or equal to 90°.

3. The noise control device according to claim 2, characterized in that, Along the direction from the first cavity to the second cavity, there is an included angle β between the plane where the second baffle and the second cavity are located, the included angle β being greater than or equal to 30° and less than or equal to 90°.

4. The noise control device according to claim 3, characterized in that, The included angle α is 45° and the included angle β is 90°.

5. The noise control device according to claim 2, characterized in that, The triangular tooth structure includes multiple sub-triangular blocks, which are distributed sequentially along the second free end, with adjacent sub-triangular blocks connected together.

6. The noise control device according to claim 5, characterized in that, The sub-triangular block is an equilateral triangle.

7. The noise control device according to any one of claims 2-6, characterized in that, The number of the second cavity is at least two, and the at least two second cavities are distributed sequentially at intervals. The number of the second baffle is at least two, and the second baffle and the second cavity correspond one to one. Each second cavity has a corresponding second baffle on its front edge. And / or, the noise control device is provided with a base frame, the first spoiler and the second spoiler are disposed on the base frame, the base frame is used to be disposed on the aircraft and is disposed corresponding to the first cavity and the second cavity.

8. The noise control device according to claim 1, characterized in that, The square tooth structure includes multiple sub-square blocks, which are evenly spaced along the first free end.

9. A type of aircraft, characterized in that, The vehicle includes a noise control device as described in any one of claims 1-8, the vehicle includes a first cavity and a second cavity, and the first fixed end is disposed at the edge of the first cavity.

10. The aircraft according to claim 9, characterized in that, The distance between the first cavity and the second cavity is greater than the length of the first cavity.

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