Forced rotation noise reduction test device, noise suppression test system and method
By designing a forced rotation noise reduction test device and system, the engineering problem of noise control for aircraft landing gear was solved, stable operation and effective noise suppression in a wind tunnel environment were achieved, and an efficient noise testing method was provided.
Patent Information
- Application Number
- CN202511058192.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-30
- Publication Date
- 2025-10-17
AI Technical Summary
Existing aircraft landing gear noise control devices and test systems have not yet been engineered, cannot operate stably in a wind tunnel environment, and are difficult to verify the noise reduction effect, making it difficult to optimize the noise suppression design.
A forced rotation noise reduction test device was designed, which included a support structure and a test piece mounting structure. The model test piece rotated around its axis to actively disturb the wind flow. Combined with an anechoic chamber and noise sensors, it simulated the aerodynamic environment of an aircraft landing gear and conducted tests with various parameter states.
It has realized noise suppression tests under different flight conditions, verified the noise reduction effect of the forced rotation device, and provided high-resolution sound field analysis, which is suitable for noise suppression of aircraft landing gear.
Smart Images
Figure CN120800732A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of aviation noise testing, in particular to a forced rotation noise reduction testing device, a noise suppression testing system and method. BACKGROUND
[0002] In the process of take-off and landing of an aircraft in the aviation equipment industry, the deployment of the landing gear is inevitable, and as one of the important components outside the aircraft, the aerodynamic characteristics of the landing gear have a profound impact on the overall performance of the aircraft. The aircraft landing gear usually has a cylindrical shape, as a typical bluff body structure. When the aircraft is flying, the airflow will flow through the landing gear, and due to the boundary layer separation and periodic vortex shedding phenomenon, the wake region of the landing gear is prone to form an unstable shear layer and an alternating Karman vortex street. This flow instability not only significantly increases the aerodynamic drag of the surface of the aircraft landing gear structure, but also is accompanied by strong aerodynamic noise generation, which becomes one of the key bottlenecks affecting the noise airworthiness certification of the aircraft, especially during high-speed flight and landing stages, the noise problem is particularly prominent.
[0003] In order to solve this problem, scholars have proposed various aircraft landing gear noise control methods, mainly divided into passive control and active control. Passive control technology usually optimizes the structure geometry or surface material to achieve noise suppression without introducing external energy. Typical passive control methods include: porous coating, wavy cylinder, splitter plate or periodic microstructure, etc. Although these methods have the advantages of simple structure, low energy consumption, strong engineering implementability, etc., their noise reduction effect is highly dependent on specific geometric parameters and incoming flow conditions during flight, and it is difficult to work effectively under wide speed or complex turbulent flow conditions. Common active control methods include blowing and suction jet control and plasma excitation. However, the above methods often fail to control the effect under high-speed flight or strong disturbance flow field, and are difficult to achieve long-term stable operation, limiting their wide application in the aviation field.
[0004] In recent years, forced rotation technology has received widespread attention in the field of flow control. This technology drives the cylinder to rotate around its own axis at a certain speed through external force, actively disturbs the incoming flow structure, significantly changes the development mode of the wake shear layer, and thus reduces noise radiation. For aircraft landing gear, this technology is expected to effectively reduce aerodynamic noise. However, current forced rotation research mostly focuses on theoretical analysis and numerical simulation, lacking an engineering forced rotation noise reduction device that can stably operate in a wind tunnel environment, has adjustable rotation speed, compact structure and is easy to integrate.
[0005] In addition, a perfect noise suppression test system and evaluation method has not been established at present, leading to difficulty in promoting the verification and optimal design of noise reduction performance. Therefore, it is urgent to develop a noise reduction test device for active control and aircraft landing gear noise control, and to support the construction of an efficient and reliable wind tunnel test system and test method to verify the noise reduction effect under different flight conditions, so as to promote the application and optimization in the field of aircraft landing gear. SUMMARY
[0006] The technical problem to be solved by the present application is that the forced rotation device and test system for aircraft landing gear noise control are still in the theoretical stage, and the actual effect cannot be verified. The purpose is to provide a forced rotation noise reduction test device, noise suppression test system and method, so that the model experimental piece rotates around its own axis at a certain speed, actively disturbs the wind flow from the wind tunnel nozzle, changes the original evolution law of the wake shear layer, and realizes the experiment of suppressing the aircraft landing gear noise by forcing the rotation of the bluff body structure (such as the main strut or the inclined support) in the aircraft landing gear.
[0007] The present application is realized by the following technical scheme: A forced rotation noise reduction test device, comprising a support structure and an experimental piece mounting structure, the support structure is connected to the outlet end of the wind tunnel nozzle; the experimental piece mounting structure is detachably connected to the support structure, and the model experimental piece is rotatably connected to the experimental piece mounting structure, and the model experimental piece has a set angle with the direction of the wind flow from the wind tunnel nozzle.
[0008] The beneficial effects of the present application are that the support structure is connected to the outlet end of the wind tunnel nozzle, and the experimental piece mounting structure is detachably connected to the support structure, which facilitates disassembly and replacement, and the model experimental piece is rotatably connected to the experimental piece mounting structure, which supports and positions the model experimental piece to ensure the stability of the model experimental piece during work, avoids affecting the accuracy of the detection data due to the stability of the support structure, and also sets an angle between the model experimental piece and the direction of the wind flow from the wind tunnel nozzle, so that the model experimental piece rotates around its own axis at a certain speed, actively disturbs the wind flow from the wind tunnel nozzle, affects the formation of the wake shear layer, and changes the original evolution law of the wake shear layer, thereby reducing the noise radiation of the model experimental piece, and realizing the experiment of suppressing the aircraft landing gear noise by forcing the rotation of the bluff body structure (such as the main strut or the inclined support) in the aircraft landing gear.
[0009] In some embodiments, the set angle is 90°. By setting the set angle to 90°, the real state of the propeller and the wind flow is simulated to improve the accuracy of the obtained data.
[0010] In some embodiments, the support structure comprises an upper end plate and a lower end plate, the upper end plate and the lower end plate are connected to the upper end and the lower end of the wind tunnel nozzle respectively, and the model experiment piece is located between the upper end plate and the lower end plate. By setting the upper end plate and the lower end plate to support the model experiment piece, the position of the model experiment piece is symmetrical and the structure is stable.
[0011] In some embodiments, the upper end plate and the lower end plate are both L-shaped plates, the vertical sections of the upper end plate and the lower end plate are fixedly connected to the outlet end of the wind tunnel nozzle respectively, the horizontal sections extend along the direction of the wind flow emitted by the wind tunnel nozzle, and the upper end and the lower end of the model experiment piece are rotatably connected to the middle part of the corresponding horizontal section. By setting the upper end plate and the lower end plate in the shape of an L-shaped plate, and connecting the vertical sections to the wind tunnel nozzle, the strength and rigidity of the connection point are improved, and the horizontal sections are also extended along the direction of the wind flow emitted by the wind tunnel nozzle to guide the wind flow out of the wind tunnel nozzle, so that the wind flow can directly act on the model experiment piece, thereby ensuring the accuracy of the experimental data.
[0012] In some embodiments, the experiment piece mounting structure comprises an upper mounting plate and a lower mounting plate, the upper mounting plate is detachably connected to the upper end plate, the lower mounting plate is detachably connected to the lower end plate, the upper end of the model experiment piece is rotatably connected to the upper mounting plate through a rolling piece, and the lower end of the model experiment piece is rotatably connected to the lower mounting plate through a rolling piece. By detachably connecting the upper mounting plate and the lower mounting plate to the upper end plate and the lower end plate, it is convenient to replace and maintain, and by rotatably connecting the two ends of the model experiment piece through rolling pieces, it is convenient to constrain the movement track of the model experiment piece, reduce friction and disperse load, thereby ensuring the stable operation of the model experiment piece in the expected track.
[0013] In some embodiments, a back-shaped frame and a driving motor are further included, the back-shaped frame is detachably connected to the lower end of the lower end plate, the driving motor is fixedly connected to the back-shaped frame, and the output shaft of the driving motor is connected to the model experiment piece through a shaft coupling. By setting the back-shaped frame to install the driving motor, the stability of the driving motor during operation is ensured, and by setting the shaft coupling to connect the output shaft of the driving motor to the model experiment piece, the torque of the driving motor is transmitted through the shaft coupling, displacement is compensated, and damping is buffered.
[0014] The noise suppression test system comprises the forced rotation noise reduction test device and the anechoic chamber, the noise reduction test device is installed in the anechoic chamber, the wind tunnel nozzle of the noise reduction test device is sealingly connected to a side wall of the anechoic chamber, a plurality of noise sensors are installed in the anechoic chamber, and the plurality of noise sensors are arranged in an arc shape along the airflow direction with the center of the model test piece as the center of the arc shape.
[0015] In some embodiments, the noise sensors comprise 9 noise sensors, the arc-shaped angle range formed by the 9 noise sensors is 50-130 degrees in the direction of the airflow flow direction, the angle between two adjacent noise sensors is 10 degrees, and the radius of the arc shape is 1-2 meters.
[0016] In some embodiments, the noise suppression test system further comprises a collector, the collector is arranged on the side wall of the anechoic chamber and located at an end away from the wind tunnel nozzle.
[0017] A test method of a noise suppression test system, comprising the following steps: testing each of a plurality of model test pieces in different test conditions to obtain noise test data; and analyzing the noise test data to obtain the noise reduction effect and noise suppression capacity of the model test pieces in different test conditions.
[0018] Compared with the prior art, the present application has the following advantages and beneficial effects: 1. The model experiment piece is set with an angle to the wind flow direction from the wind tunnel nozzle, the model experiment piece continuously rotates around its own axis at a certain rotating speed to actively disturb the wind flow from the wind tunnel nozzle, to affect the formation of the wake shear layer and change the original evolution rule of the wake shear layer, thereby reducing the noise radiation of the model experiment piece, so as to realize the experiment of suppressing the noise of the aircraft landing gear by forcibly rotating the blunt body structure (such as the main strut or the inclined support) in the aircraft landing gear.
[0019] 2. The noise reduction test device is installed in the anechoic chamber, and the wind tunnel nozzle is sealingly connected with the anechoic chamber, so that the wind flow from the wind tunnel nozzle can completely enter the anechoic chamber, and a plurality of noise sensors are arranged in an arc shape along the airflow direction with the center of the model experiment piece as the center, so as to simulate the aerodynamic environment faced in the process of unfolding and flying of the aircraft landing gear, and verify the noise suppression effect of the forced rotation technology on the aircraft landing gear.
[0020] 3. Each of the model experiment pieces with different parameters (different diameters, different lengths, different materials and different rotating speeds) is tested under different test conditions (different wind speeds), so as to obtain the noise reduction performance (noise suppression effect) of different models (different diameters, lengths and materials) under each rotating speed state under different test conditions, and the noise control performance of the forced rotation device and the test system under various aerodynamic conditions is verified, thereby realizing the aerodynamic noise suppression test of the aircraft landing gear and other key components. BRIEF DESCRIPTION OF DRAWINGS
[0021] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor. In the drawings: Figure 1 It is a structural diagram of the test device in the present application; Figure 2 It is a vertical center sectional view of the test device in the present application; Figure 3 It is a top view of the noise suppression test system in the present application; Figure 4 It is a noise spectrum result graph when the airflow speed is 55 m / s in the present application; Figure 5 It is a noise spectrum result graph when the airflow speed is 60 m / s in the present application; Figure 6 It is a total sound pressure level result graph of the cylinder as the experiment piece at θ = 50°-130° when the airflow speed is 55 m / s. Figure 7 The total sound pressure level of the cylinder as the experimental piece at a wind speed of 60 m / s is shown in the graph at 50-130 degrees.
[0022] Markings in the drawings and corresponding names of parts: Wind tunnel nozzle 1, connecting plate 2, upper end plate 3, upper mounting plate 3-1, lower end plate 4, lower mounting plate 4-1, model experimental piece 5, coupling 6, drive motor 7, controller 8, power supply system 9, back-shaped frame 10, circular end cover 11, locking nut 12, rolling piece 13, noise sensor 14, collector 15, muffler 16. DETAILED DESCRIPTION
[0023] In order to make the purpose, technical scheme and advantages of the present application clearer and more apparent, the present application will be further described in detail below with reference to the embodiments and drawings, the illustrative embodiments of the present application and the description thereof are only used to explain the present application, and are not regarded as a limitation to the present application.
[0024] Throughout the specification, the reference to “one embodiment”, “an embodiment”, “one example” or “an example” means that a particular feature, structure or characteristic described in connection with the embodiment or example is included in at least one embodiment of the present application. Therefore, the phrases “one embodiment”, “an embodiment”, “one example” or “an example” appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. In addition, specific features, structures or characteristics can be combined in one or more embodiments or examples in any appropriate combination and / or sub-combination. In addition, those of ordinary skill in the art should understand that the drawings provided herein are for illustrative purposes only, and the drawings are not necessarily drawn to scale. The term “and / or” used herein includes any and all combinations of one or more of the relevant listed items.
[0025] In the description of the present application, the terms “front”, “back”, “left”, “right”, “up”, “down”, “vertical”, “horizontal”, “high”, “low”, “inner”, “outer” and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation to the scope of protection of the present application.
[0026] The terms “first”, “second” and the like used in the present application are only for the purpose of distinguishing the corresponding parts for the sake of clarity, and are not intended to limit any order or emphasize importance. In addition, the term “connection” used herein can be direct connection or indirect connection via other components, without special description.
[0027] Embodiment 1 With reference to Figures 1-2 , the embodiment 1 provides a forced rotation noise reduction test device, which comprises a support structure and an experimental piece mounting structure, the support structure is connected at an outlet end of a wind tunnel nozzle 1; the experimental piece mounting structure is detachably connected on the support structure, a model experimental piece 5 is rotatably connected on the experimental piece mounting structure, and the model experimental piece 5 has a set included angle with the wind flow direction of the wind flow ejected from the wind tunnel nozzle 1. The model experimental piece 5 continuously rotates around its own axis at a certain rotating speed to actively disturb the wind flow ejected from the wind tunnel nozzle 1, affect the formation of the wake shear layer, and change the original evolution rule of the wake shear layer, so as to reduce the noise radiation of the model experimental piece 5, so as to realize the experiment of suppressing the noise of the aircraft landing gear by forcibly rotating the blunt body structure (such as the main strut or the inclined support) in the aircraft landing gear.
[0028] With reference to Figures 1-2 , the model experimental piece 5 in the embodiment is a cylindrical blunt body (such as an aircraft landing gear). The outlet end of the wind tunnel nozzle 1 is connected with a connecting plate 2 through bolts, and the upper end plate 3 and the lower end plate 4 are both connected on the connecting plate 2 through bolts.
[0029] With reference to Figures 1-2 , the set included angle is 90°. By setting the set included angle to 90°, the real state of the propeller and the wind flow is simulated, so as to improve the accuracy of the obtained data.
[0030] With reference to Figures 1-2 , the support structure comprises an upper end plate 3 and a lower end plate 4, the upper end plate 3 and the lower end plate 4 are connected at the upper end and the lower end of the wind tunnel nozzle 1 respectively, and the model experimental piece 5 is located between the upper end plate 3 and the lower end plate 4. By setting the upper end plate 3 and the lower end plate 4 to support the model experimental piece 5, the position symmetry and the structure stability of the model experimental piece 5 are ensured.
[0031] With reference to Figures 1-2 , the upper end plate 3 and the lower end plate 4 are both in the shape of L-shaped plate, the vertical sections of the upper end plate 3 and the lower end plate 4 are fixedly connected with the outlet end of the wind tunnel nozzle 1 respectively, the horizontal sections extend along the wind flow direction of the wind flow ejected from the wind tunnel nozzle 1, and the upper end and the lower end of the model experimental piece 5 are rotatably connected at the middle parts of the corresponding horizontal sections. By setting the upper end plate 3 and the lower end plate 4 in the shape of L-shaped plate, the vertical sections are connected with the wind tunnel nozzle 1, the strength and the rigidity of the connecting point are improved, and the horizontal sections extend along the wind flow direction of the wind flow ejected from the wind tunnel nozzle 1 to guide the wind flow out of the wind tunnel nozzle 1, so that the wind flow can directly act on the model experimental piece 5, so as to ensure the accuracy of the experimental data.
[0032] With reference to Figures 1-2The experimental piece mounting structure comprises an upper mounting plate 3-1 and a lower mounting plate 4-1, the upper mounting plate 3-1 is detachably connected to the upper end plate 3, the lower mounting plate 4-1 is detachably connected to the lower end plate 4, the upper end of the model experimental piece 5 is rotatably connected to the upper mounting plate 3-1 through a rolling piece 13, and the lower end of the model experimental piece 5 is rotatably connected to the lower mounting plate 4-1 through a rolling piece 13. By detachably connecting the upper mounting plate 3-1 and the lower mounting plate 4-1 above the upper end plate 3 and the lower end plate 4, the model experimental piece 5 is rotatably connected at both ends through the rolling piece 13, the movement track of the model experimental piece 5 is conveniently constrained through the rolling piece 13, friction is reduced, and load is dispersed, so that the model experimental piece 5 can stably operate in the expected track.
[0033] Referring to Figures 1-2 The application also comprises a back-shaped frame 10 and a driving motor 7, the back-shaped frame 10 is detachably connected to the lower end of the lower end plate 4, the driving motor 7 is fixedly connected to the back-shaped frame 10, and the output shaft of the driving motor 7 is connected with the model experimental piece 5 through a shaft coupling 6. The driving motor 7 is mounted on the back-shaped frame 10, so that the stability of the driving motor 7 during operation is ensured, and the output shaft of the driving motor 7 is connected with the model experimental piece 5 through the shaft coupling 6, so that the torque of the driving motor 7 is transmitted through the shaft coupling 6, displacement is compensated, and damping and buffering are achieved.
[0034] Referring to Figures 1-2 Specifically, the two rolling pieces 13 are respectively embedded in the hole positions of the upper end plate 3 and the lower end plate 4, a locking nut 12 is arranged above the rolling piece 13 to prevent loosening, and a circular end cover 11 is arranged outside the rolling piece 13 to limit and compress. The rolling piece 13 in the application can be a bearing, a self-lubricating circular tube or a shaft sleeve.
[0035] Embodiment 2 Referring to Figure 3 The embodiment 2 provides a noise suppression test system, which comprises the forced rotation noise reduction test device and a soundproof room 16, the noise reduction test device is mounted in the soundproof room 16, the wind tunnel nozzle 1 of the noise reduction test device is sealingly connected to one side wall of the soundproof room 16, a plurality of noise sensors are mounted in the soundproof room 16, and the plurality of noise sensors are arranged in an arc shape along the airflow direction with the center of the model experimental piece 5 as the center. The noise reduction test device is mounted in the soundproof room 16, the wind tunnel nozzle 1 is sealingly connected to the soundproof room 16, so that the airflow sprayed from the wind tunnel nozzle 1 can completely enter the soundproof room 16, and the plurality of noise sensors are arranged in an arc shape along the airflow direction with the center of the model experimental piece 5 as the center, so as to simulate the aerodynamic environment faced by the aircraft landing gear during the process of unfolding and flying, and verify the noise suppression effect of the forced rotation technology on the aircraft landing gear.
[0036] Referring to Figure 3 , the noise sensor includes 9, with the airflow flow direction as the basis, the arc-shaped angle range formed by the 9 noise sensors 14 is 50°-130°, the angle between two adjacent noise sensors 14 is 10°, and the radius of the arc is 1m-2m. The radiation noise characteristics in each direction can be effectively captured, thereby realizing high-resolution sound field analysis.
[0037] Referring to Figure 3 , it also includes a collector 15 arranged on the side wall of the anechoic chamber 16 and located away from one end of the wind tunnel nozzle 1. By arranging the collector 15, the airflow ejected from the wind tunnel nozzle 1 is finally discharged through the collector 15.
[0038] Referring to Figure 3 , the size of the acoustic anechoic wind tunnel is 0.55m x 0.4m, which is located in the full-anechoic chamber 16. The sensing measurement system is equipped with 9 noise sensors 14 (Mic1-Mic9), which are arranged in an arc array around the model test piece 5 as the center in the airflow direction.
[0039] Referring to 3, preferably, the radius of the arc is 1.5 meters, and Mic5 is located at 90°. Mic5 is the position with the greatest noise impact and is the key monitoring object.
[0040] Referring to Figure 3 , it also includes a control system composed of a controller 8 and a power supply system 9, the controller 8 is used to set the rotation speed of the cylinder and control the operation of the motor through wired mode.
[0041] Embodiment 3 Referring to Figures 1-7 , the embodiment 3 provides a test method of a noise suppression test system, which includes the following steps: testing each of the model test pieces 5 in multiple different parameter states under different test conditions to obtain noise test data; and analyzing the noise test data to obtain the noise reduction effect and noise suppression capacity of the model test pieces 5 in different parameter states under different test conditions. By testing each of the model test pieces 5 in multiple different parameter states (different diameters, different lengths, different materials and different rotation speeds) under different test conditions (different wind speeds), the noise reduction performance (noise suppression effect) of different models (different diameters, lengths and materials) under each rotation speed state under different test conditions is obtained, the noise control performance of the forced rotation device and the test system under multiple aerodynamic conditions is verified, and the aerodynamic noise suppression test of the aircraft landing gear and other key components is realized.
[0042] Through testing under multiple sets of different rotating speeds and airflow speeds, the aerodynamic noise performance of the aircraft landing gear under different flight stages and speeds can be accurately simulated, and data support can be provided for further optimization of noise reduction schemes.
[0043] Specifically, a cylinder with a diameter of 60 mm and a height of 400 mm is used as the model experiment piece 5, a 1 / 2 inch 46AE microphone produced by G.R.A.S. is used, the sampling frequency is set to 51.2 kHz, and 10 seconds of noise data is continuously collected under each set of working conditions. During the experiment, the above experimental model is placed under different combinations of wind speed and rotating speed for testing, the noise response signal is recorded, and the obtained acoustic data is analyzed to quantify the noise reduction performance and noise suppression effect of the model under different rotating speeds under different test conditions. The rotating speed of the cylinder is set to 0-8000 rpm with a step of 200 rpm, and the wind speed is set to 20-60 m / s with a step of 5 m / s, in order to simulate various inflow conditions that may be encountered in actual applications and evaluate the noise suppression ability of the forced rotation device in complex flow environment. By performing spectral analysis on the noise signals collected by the microphone, the power spectral density (PSD) variation curves of the Mic5 measuring point under the conditions of wind speeds of 55 m / s and 60 m / s, rotating speeds of 7000 rpm and 8000 rpm are obtained as shown in Figure 4 and Figure 5 The total sound pressure level (OASPL) distribution diagrams of each azimuth angle under the corresponding working conditions are plotted as shown in Figure 6 and Figure 7 It can be seen from Figure 4 and Figure 5 Under the conditions of high airflow speeds of 55 m / s and 60 m / s, the forced rotation driving at 7000 rpm and 8000 rpm can effectively weaken the single-tone noise caused by the vortex shedding main frequency, with a reduction of about 16 dB at 55 m / s and about 17 dB at 60 m / s. In addition, the multiple frequency noise appearing in the spectrum is mainly caused by the motor driving process, and the amplitude is much lower than that of the vortex shedding main frequency component, and the proportion in the overall energy is very small and can be ignored. Compared with traditional jet flow control and other active noise reduction methods, the additional noise introduced by this system is lower, which has obvious advantages.
[0044] Referring to Figure 6 and Figure 7, further indicated that, in each test azimuth angle, the forced rotation control device shows stable noise reduction ability, the OASPL value is significantly reduced compared with the reference state, showing good spatial consistency and directionality control ability. It is worth noting that the experiment shows that the higher the speed is not the better the noise reduction effect, but there is a certain optimal speed interval, which is conducive to realizing the optimal noise suppression effect while controlling the energy consumption. In summary, the present embodiment fully verifies the proposed forced rotation device and its test system in various aerodynamic conditions The steady-state operation reliability and superior noise control performance of the device have good engineering adaptability and application prospect. The efficiency and stability of the system are particularly suitable for the study of aerodynamic noise suppression of aircraft landing gear and other key components, and have wide application potential.
[0045] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.
Claims
1. A forced rotation noise reduction test device, characterized in that: include: A support structure connected to the outlet end of the wind tunnel nozzle; The experimental piece mounting structure is detachably connected to the supporting structure, and the model experimental piece is rotatably connected to the experimental piece mounting structure. The model experimental piece has a set angle with the direction of the wind flow ejected from the wind tunnel nozzle.
2. The forced rotation noise reduction testing device according to claim 1, characterized in that: The setting angle is 90°.
3. The forced rotation noise reduction testing device according to claim 1, characterized in that: The support structure includes an upper end plate and a lower end plate, wherein the upper end plate and the lower end plate are respectively connected to the upper end and the lower end of the wind tunnel nozzle, and the model test piece is located between the upper end plate and the lower end plate.
4. The forced rotation noise reduction testing device according to claim 3, characterized in that: The upper end plate and the lower end plate are both L-shaped plates, the vertical sections of the upper end plate and the lower end plate are respectively fixedly connected to the outlet ends of the wind tunnel nozzle, and the horizontal sections extend along the direction of the wind flow ejected from the wind tunnel nozzle. The upper end and the lower end of the model test piece are respectively rotatably connected to the middle part of the corresponding horizontal section.
5. The forced rotation noise reduction testing device according to claim 3, characterized in that: The experimental piece mounting structure includes an upper mounting plate and a lower mounting plate, the upper mounting plate is detachably connected to the upper end plate, the lower mounting plate is detachably connected to the lower end plate, the upper end of the model experimental piece is rotatably connected to the upper mounting plate via a rolling piece, and the lower end of the model experimental piece is rotatably connected to the lower mounting plate via a rolling piece.
6. The forced rotation noise reduction testing device according to claim 5, characterized in that: It also includes a circular frame and a drive motor, wherein the circular frame is detachably connected to the lower end of the lower end plate, the drive motor is fixedly connected to the circular frame, and the output shaft of the drive motor is connected to the model test piece through a coupling.
7. A noise suppression test system, characterized in that: The invention comprises a forced rotation noise reduction test device and an anechoic chamber as described in any one of claims 1 to 6, wherein the noise reduction test device is installed in the anechoic chamber, the wind tunnel nozzle of the noise reduction test device is sealed and connected to a side wall of the anechoic chamber, and a plurality of noise sensors are installed in the anechoic chamber, and the plurality of noise sensors are evenly distributed in an arc shape along the airflow direction with the center of the model test piece as the center of the circle.
8. The noise suppression test system according to claim 7, wherein: There are nine noise sensors. The angle range of the arc formed by the nine noise sensors is 50° to 130° based on the airflow direction. The angle between two adjacent noise sensors is 10°. The radius of the arc is 1m to 2m.
9. The noise suppression test system according to claim 7, wherein: The utility model further comprises a collector, which is arranged on the side wall of the muffler chamber and located at an end away from the wind tunnel nozzle.
10. A method for testing a noise suppression test system, characterized in that: The following steps are involved: Testing each of the model test pieces in a plurality of different parameter states under different test conditions to obtain noise test data; Based on the noise test data analysis, the noise reduction effect and noise suppression ability of the model test piece with different parameter states under different test conditions are obtained.