High sound pressure test noise elimination device and aircraft test noise elimination system

Abstract

The invention provides a high sound pressure test noise elimination device and a noise elimination system for aircraft test. The device comprises a sound insulation test cabin which is used for accommodating equipment to be subjected to high sound pressure test and is communicated with a sound outlet part of acoustic test equipment which generates high sound pressure noise; wherein the sound insulation test cabin is of a closed sound room structure, and the wall body and the roof of the sound insulation test cabin are of sound insulation structures; the exhaust channel is communicated to the interior of the sound insulation test cabin and used for exhausting air in the sound insulation test cabin, and a sound absorption insertion piece is arranged in the exhaust channel. Through the structural design of the sound insulation test cabin and the exhaust channel, the high-strength noise generated in the operation of the acoustic wave traveling wave tube can be effectively reduced, and the influence on the surrounding environment is reduced.

Description

High sound pressure test noise silencing device, aircraft test noise silencing system Technical Field

[0001] This application relates to the field of spacecraft dynamics testing technology, and more specifically, to a high sound pressure test noise silencing device and a spacecraft testing noise silencing system. Background Technology

[0002] Aircraft (such as spacecraft, airplanes, and weapons) need to withstand high-intensity noise environments during their mission cycles, and this high-intensity noise can affect their structural integrity and functional performance. Therefore, the high-intensity noise test results of aircraft have become an important indicator for evaluating their performance.

[0003] In related technologies, high sound pressure level noise environments are typically generated on the ground using experimental devices such as traveling wave tubes to test aircraft. However, if this high sound pressure level noise is discharged directly without protection, it will cause serious noise pollution to the surrounding environment and may even harm people in the vicinity.

[0004] Therefore, there is a need for an efficient and stable noise reduction device that can effectively reduce the high-intensity noise generated by the acoustic traveling wave tube during operation without affecting the performance of the traveling wave tube itself, thereby reducing its impact on the surrounding environment. Summary of the Invention

[0005] The purpose of this application is to provide a high sound pressure level test noise silencing device and an aircraft test noise silencing system, which can solve at least one of the aforementioned technical problems. The specific solution is as follows:

[0006] According to a specific embodiment of this application, in a first aspect, a high sound pressure level test noise silencing device is provided, the device comprising:

[0007] A sound insulation test chamber is used to house the equipment to be tested for high sound pressure levels and is connected to the sound-emitting components of the acoustic test equipment that generates high sound pressure noise; wherein, the sound insulation test chamber is a sealed sound room structure, and the walls and roof of the sound insulation test chamber are all made of sound insulation structure;

[0008] An exhaust channel is connected to the interior of the sound insulation test chamber to exhaust the air inside the sound insulation test chamber. The exhaust channel is equipped with sound-absorbing inserts.

[0009] In some optional embodiments, the walls and roof of the sound insulation test chamber are both double-walled structures with a cavity between the two wall structures.

[0010] In some optional embodiments, the wall structure, from the inside to the outside of the sound insulation test chamber, includes galvanized steel plate, environmentally friendly sound-absorbing cotton, thick gypsum board, rubber damping, and galvanized steel plate in sequence.

[0011] In some alternative embodiments, environmentally friendly sound-absorbing cotton 13 is attached to at least one side of the wall inside the cavity.

[0012] In some alternative embodiments, sound-absorbing wedges are provided on the walls and roof of the sound insulation test chamber facing the sound-emitting components of the acoustic testing equipment.

[0013] In some optional embodiments, multiple sets of low-frequency sound-absorbing inserts and multiple sets of mid-to-high-frequency sound-absorbing inserts are arranged sequentially in the gas flow direction of the exhaust channel. The low-frequency sound-absorbing inserts are closer to the sound insulation test chamber than the high-frequency sound-absorbing inserts. Each set of low-frequency sound-absorbing inserts includes multiple low-frequency sound-absorbing inserts, and each set of mid-to-high-frequency sound-absorbing inserts includes multiple mid-to-high-frequency sound-absorbing inserts. Both the low-frequency sound-absorbing inserts and the mid-to-high-frequency sound-absorbing inserts are arranged sequentially in the cross-sectional direction of the exhaust channel.

[0014] In some optional embodiments, the low-frequency sound-absorbing inserts are arranged in two groups as a unit for airflow direction, and the two groups of low-frequency sound-absorbing inserts in the same unit contain different numbers of inserts; the mid-to-high frequency sound-absorbing inserts are arranged in two groups as a unit for airflow direction, and the two groups of mid-to-high frequency sound-absorbing inserts in the same unit contain different numbers of inserts.

[0015] In some optional embodiments, the outer shells of the low-frequency sound-absorbing inserts and the mid-to-high-frequency sound-absorbing inserts are both perforated aluminum plates, and the sound-absorbing material filled inside is wrapped by a sound-permeable membrane; wherein, the thickness of the low-frequency sound-absorbing insert along the airflow direction is greater than the thickness of the mid-to-high-frequency sound-absorbing insert along the airflow direction.

[0016] In some alternative embodiments, the exhaust passage has multiple bends in the gas flow direction.

[0017] According to a specific embodiment of this application, in a second aspect, a noise silencing system for aircraft testing is provided, including the aforementioned high sound pressure test noise silencing device and acoustic traveling wave tube, for generating high sound pressure test noise to perform high sound pressure level noise testing on the equipment under test housed in the soundproof test chamber.

[0018] Compared with the prior art, the above-described solutions of this application have at least the following beneficial effects:

[0019] It is suitable for high sound pressure test scenarios, can stably accommodate the equipment to be tested and reliably dock with the acoustic test equipment. The sound insulation test chamber and the sound-absorbing insert work together to effectively block and absorb high sound pressure noise, significantly reducing noise pollution and personnel injury risks.

[0020] While ensuring smooth airflow (meeting the test heat dissipation requirements), the exhaust channel uses sound-absorbing inserts to specifically reduce noise, preventing noise leakage through the exhaust path without affecting the performance of the acoustic testing equipment itself.

[0021] The combination of a sealed acoustic chamber structure and an exhaust channel design balances sound insulation and airflow, making it suitable for wideband noise reduction requirements. At the same time, the soundproof test chamber can effectively prevent airflow back to the acoustic testing equipment and avoid interference with the test, thus improving the environmental adaptability and safety of high sound pressure testing. Attached Figure Description

[0022] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings:

[0023] Figure 1 is a schematic diagram of the overall structure of the high sound pressure test noise silencing device provided in the embodiment of this application;

[0024] Figure 2 is a side view of a high sound pressure test noise silencing device provided in an embodiment of this application;

[0025] Figure 3 is a schematic diagram of the wall structure of the soundproof test chamber of the high sound pressure test noise silencing device provided in the embodiment of this application;

[0026] Figure 4 is a schematic diagram of the exhaust channel of the high sound pressure test noise silencing device provided in the embodiment of this application;

[0027] Explanation of reference numerals in the attached figures:

[0028] 1. Sound insulation test chamber; 2. Exhaust channel; 11. First wall; 12. Cavity; 13. Environmentally friendly sound-absorbing cotton; 14. Second wall; 21. Low-frequency sound-absorbing insert; 22. Mid-to-high frequency sound-absorbing insert; 3. Flange. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0030] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase "comprising one" does not exclude the presence of other identical elements in the article or device that includes said element.

[0031] Spacecraft, aircraft, weapons, and other flying vehicles are subjected to high-intensity noise during their missions, which may affect their structural integrity and functional performance. With technological advancements, the speed of flying vehicles is gradually increasing, leading to a corresponding increase in the noise load they experience. To accurately simulate this in ground tests, experimental devices such as traveling wave tubes are needed to generate high sound pressure level noise environments, with maximum sound pressure levels reaching 165 dB to 170 dB. If such high sound pressure levels are not protected, direct discharge will cause severe noise pollution to the surrounding environment and may even harm nearby personnel.

[0032] Therefore, the high sound pressure level test noise silencing device provided in this application includes: a soundproof test chamber for accommodating the equipment to be tested under high sound pressure level, and connected to the sound-emitting component of the acoustic test equipment that generates high sound pressure level noise; wherein, the soundproof test chamber is a sealed acoustic chamber structure, and the walls and roof of the soundproof test chamber are made of soundproof structure; an exhaust channel is connected to the interior of the soundproof test chamber for exhausting the air inside the soundproof test chamber, and the exhaust channel is provided with sound-absorbing inserts. In this way, it can adapt to high sound pressure level test scenarios, stably accommodate the equipment to be tested, and reliably connect with the acoustic test equipment. The soundproof test chamber and the sound-absorbing inserts work together to effectively block and absorb high sound pressure level noise, significantly reducing noise pollution and the risk of personal injury.

[0033] The optional embodiments of this application are described in detail below with reference to Figures 1-4.

[0034] Example 1:

[0035] As shown in Figures 1 and 2, according to a specific embodiment of this application, this application provides a high sound pressure level test noise silencing device, the device comprising:

[0036] The sound insulation test chamber 1 is used to house the equipment to be tested for high sound pressure and is connected to the sound output component of the acoustic test equipment that generates high sound pressure noise; wherein, the sound insulation test chamber 1 is a sealed sound room structure, and the walls and roof of the sound insulation test chamber 1 are all made of sound insulation structure.

[0037] Exhaust channel 2 connects to the interior of sound insulation test chamber 1 and is used to exhaust the air inside sound insulation test chamber 1. Sound-absorbing inserts are provided inside exhaust channel 2.

[0038] Understandably, the internal space of the sound insulation test chamber 1 can accommodate equipment such as spacecraft and aircraft components awaiting high sound pressure level testing. It is reliably connected to the sound-emitting components of acoustic testing equipment (such as traveling wave tubes). For example, to prevent sound leakage, the diffusion section between the sound insulation test chamber 1 and the traveling wave tube is connected by a flange 3, with a gasket inside the connection end. The acoustic testing equipment can directionally transmit high sound pressure level noise (such as 165dB to 170dB) into the sound insulation test chamber 1, providing a noise environment that meets the simulation requirements for the equipment under test.

[0039] Because the sound insulation test chamber 1 adopts a completely sealed acoustic chamber structure, the fully enclosed design reduces noise leakage paths and prevents direct diffusion of high sound pressure noise. Simultaneously, it isolates external environmental noise from entering the test chamber, providing an interference-free, pure noise environment for testing and ensuring the accuracy of test results. Its structural strength is adapted to high sound pressure testing conditions, capable of withstanding acoustic vibrations caused by noise levels of 165dB to 170dB. Furthermore, it is fixed to the ground by no fewer than four electrochemical anchors to prevent positional shifts during testing, further ensuring test stability.

[0040] Exhaust channel 2, as a supporting functional unit of the sound insulation test chamber 1, connects to the interior of the chamber at one end and to the external environment at the other, forming a smooth airflow path. This allows for the timely removal of hot air generated during equipment operation from within the chamber, preventing temperature increases from affecting equipment operation and testing accuracy. The channel adopts a dual-channel layout design to accommodate high-flow exhaust requirements and can guarantee 1000Nm of exhaust volume. 3 With an exhaust volume of [value] / min, it meets the heat dissipation requirements of high sound pressure level testing. Simultaneously, sound-absorbing inserts are integrated inside the exhaust channel 2, allowing for secondary absorption and attenuation of noise passing through it. Furthermore, the exhaust channel 2 and the soundproof test chamber 1 work together to prevent airflow backflow, effectively preventing the backflow of exhausted hot air or incompletely attenuated noise into the test chamber. This not only prevents interference with the normal operation of the acoustic testing equipment and the accuracy of the test results but also further blocks the noise leakage path.

[0041] This embodiment is adapted to high sound pressure testing scenarios, stably accommodating the equipment under test and reliably docking with the acoustic testing equipment. The soundproof test chamber 1 and the sound-absorbing inserts work together to efficiently block and absorb high sound pressure noise, significantly reducing noise pollution and the risk of personal injury. The exhaust channel 2 ensures smooth air discharge (meeting the test heat dissipation requirements) while using the sound-absorbing inserts to specifically reduce noise, preventing noise leakage through the exhaust path without affecting the performance of the acoustic testing equipment itself. The combined design of the sealed acoustic chamber structure and the exhaust channel 2 takes into account both sound insulation and airtightness, adapting to broadband noise reduction requirements. At the same time, the soundproof test chamber 1 can effectively prevent airflow back to the acoustic testing equipment and interfere with the test, improving the environmental adaptability and safety of high sound pressure testing.

[0042] Example 2:

[0043] As shown in Figures 1, 2, and 3, according to a specific embodiment of this application, this application provides a high sound pressure level test noise silencing device, which includes: a sound insulation test chamber 1 and an exhaust channel 2. The connection structure between the sound insulation test chamber 1 and the exhaust channel 2 can be referred to Figure 1. The functions of the sound insulation test chamber 1 and the exhaust channel 2 in the high sound pressure level test can be referred to the above embodiment 1, and will not be repeated here.

[0044] In this embodiment, as shown in Figure 3, the walls and roof of the sound insulation test chamber 1 are both double-wall structures, and there is a cavity 12 between the two wall structures (the first wall 11 and the second wall 14).

[0045] Understandably, the double-layered walls and cavity 12 form a composite sound insulation structure, which significantly improves the blocking effect against high sound pressure levels of 165dB to 170dB compared to a single-layered wall. The outer wall initially blocks noise penetration, cavity 12 attenuates and weakens sound wave reflection, and the inner wall further blocks residual noise. Combined with the environmentally friendly sound-absorbing cotton inside the cavity, this forms a dual protection of blocking and absorption, effectively solving the environmental pollution and personnel injury problems caused by high sound pressure noise leakage. At the same time, the double-layered walls and cavity 12 form a natural insulation layer, reducing heat exchange between the interior and exterior environments and preventing drastic temperature changes from affecting the performance of testing equipment or sound-absorbing and sound-insulating materials.

[0046] To prevent sound reflection from the traveling wave tube, sound-absorbing wedges are added to the wall directly in front of the traveling wave tube and to the top, while sound-absorbing flat plates are used on the remaining walls and floor.

[0047] Sound pressure noise blocking capability; reduces noise resonance and reflection within cavity 12. Environmentally friendly sound-absorbing cotton also has buffering properties, which can help absorb sound-induced vibrations. Combined with the rubber damping layer, it improves the structural stability of the wall and is suitable for high sound pressure test conditions. The material is environmentally friendly and highly adaptable, does not affect the original sound insulation and structural performance of the wall, and further extends the service life of the sound insulation test chamber 1.

[0048] Furthermore, in one specific embodiment, sound-absorbing wedges are provided on the walls and roof of the sound insulation test chamber 1 facing the sound-emitting components of the acoustic testing equipment.

[0049] To prevent sound reflection from the traveling wave tube, sound-absorbing wedges are added to the wall directly in front of the traveling wave tube and to the top, while sound-absorbing flat plates are used on the remaining walls and floor.

[0050] For example, the sound-absorbing wedge metal frame is an aluminum alloy perforated plate, and the filling material is an inorganic cotton environmentally friendly material (Owens Corning 24K Yike cotton), with a cutoff frequency of 50Hz.

[0051] In this embodiment, the sound-absorbing wedges are positioned directly opposite the sound-emitting components of the acoustic testing equipment, allowing for direct capture of directional high sound pressure level (SPL) noise. Combined with inorganic cotton filling material with a low cutoff frequency of 50Hz, this efficiently absorbs broadband noise energy, enhancing the noise reduction effect. It effectively reduces noise reflection and resonance within the chamber, preventing reflected noise from affecting the noise reception accuracy of the equipment under test and ensuring the purity of the testing environment. The aluminum alloy perforated plate frame balances strength and sound transmission, while the inorganic cotton material is environmentally friendly and has stable sound absorption performance, making it suitable for high SPL testing conditions and offering a long service life. The combination of directional placement and a low cutoff frequency precisely matches the noise characteristics of high SPL testing, further overcoming the narrow bandwidth limitation of existing noise reduction technologies.

[0052] Example 3:

[0053] As shown in Figures 1, 2, and 4, according to a specific embodiment of this application, this application provides a high sound pressure level test noise silencing device, which includes: a sound insulation test chamber 1 and an exhaust channel 2. The connection structure between the sound insulation test chamber 1 and the exhaust channel 2 can be referred to Figure 1. The function of the sound insulation test chamber 1 and the exhaust channel 2 in the high sound pressure level test can be referred to the above embodiment 1. The specific structure of the sound insulation test chamber 1 in some specific application scenarios can be referred to the above embodiment 2, and will not be repeated here.

[0054] In this embodiment, as shown in FIG4, multiple sets of low-frequency sound-absorbing inserts 21 and multiple sets of mid-to-high-frequency sound-absorbing inserts 22 are arranged sequentially in the gas flow direction of the exhaust channel 2. The low-frequency sound-absorbing inserts 21 are closer to the sound insulation test chamber 1 than the high-frequency sound-absorbing inserts 22. Each set of low-frequency sound-absorbing inserts 21 includes multiple low-frequency sound-absorbing inserts 21, and each set of mid-to-high-frequency sound-absorbing inserts 22 includes multiple mid-to-high-frequency sound-absorbing inserts 22. The multiple low-frequency sound-absorbing inserts 21 and the multiple mid-to-high-frequency sound-absorbing inserts 22 are arranged sequentially in the cross-sectional direction of the exhaust channel 2.

[0055] One set of sound-absorbing inserts consists of several sound-absorbing inserts arranged at preset intervals along the cross-section of the exhaust channel 2. These inserts are made of the same material and function (either all are low-frequency sound-absorbing inserts 21 or all are mid-to-high-frequency sound-absorbing inserts 22), and form the basic unit for the sound-absorbing arrangement of the exhaust channel 2. The sound-absorbing inserts within the same set are of the same type (either only low-frequency or only mid-to-high-frequency), and their outer shell material (perforated aluminum plate), internal filling material (Owens Corning 24K cotton), and wrapping method (sound-permeable membrane wrapping) are completely identical. The inserts are evenly spaced along the cross-section of the exhaust channel 2 (horizontally or longitudinally) to ensure uniform coverage of noise and airflow in the corresponding area within the channel.

[0056] Understandably, when noise from exhaust channel 2 is discharged from the sound insulation test chamber 1, low-frequency noise has stronger energy, travels farther, and tends to accumulate at the front of the channel, while mid-to-high-frequency noise attenuates relatively quickly and is more concentrated in the middle and rear of the channel. Placing low-frequency sound-absorbing inserts 21 at the front of the channel near the test chamber allows for priority and efficient absorption of the core energy of low-frequency noise; mid-to-high-frequency sound-absorbing inserts 22 are placed at the rear of the channel to specifically capture residual mid-to-high-frequency noise, forming a stepped silencing logic of first reducing low frequencies and then eliminating mid-to-high frequencies, significantly improving the overall silencing effect across a wide frequency range of 50 to 10000Hz. Noise and airflow propagate outwards along the channel synchronously. After the low-frequency inserts at the front are silencingd, the mid-to-high-frequency inserts at the rear can complete secondary silencing before the noise spreads backwards, reducing the superposition and interference of noise from different frequency bands. At the same time, the inserts are arranged sequentially along the cross-sectional direction of the channel, ensuring sufficient contact between the inserts and noise and airflow without excessively obstructing the airflow channel. Combined with the dual-channel layout, this can stably guarantee 1000Nm 3 The exhaust volume of / min meets the heat dissipation requirements.

[0057] Furthermore, in one specific embodiment, the low-frequency sound-absorbing inserts 21 are arranged in two groups as one airflow direction unit, and the two groups of low-frequency sound-absorbing inserts 21 in the same arrangement unit contain different numbers of inserts; the mid-high frequency sound-absorbing inserts 22 are arranged in two groups as one airflow direction unit, and the two groups of mid-high frequency sound-absorbing inserts 22 in the same arrangement unit contain different numbers of inserts.

[0058] The arrangement unit is the smallest combination unit that defines the same type of sound-absorbing inserts (low-frequency sound-absorbing inserts 21 or mid-to-high-frequency sound-absorbing inserts 22) along the gas flow direction of the exhaust channel 2. This unit always contains two sets of sound-absorbing inserts, and the number of individual inserts in the two sets is designed differently. Multiple of these arrangement units are arranged sequentially along the airflow direction to form a complete arrangement structure of inserts for the corresponding frequency band. Each set of inserts plays a sound-absorbing role for noise in a specific frequency band, and forms a differentiated cooperation with another set of inserts with a different number in the same arrangement unit to jointly adapt to the noise energy distribution and airflow requirements in the channel.

[0059] For example, the first arrangement unit (closest to the end of the sound insulation test chamber 1): the first group contains 2 low-frequency inserts, which are evenly spaced laterally along the cross-section of the channel (the spacing is adjusted according to the width of the channel, such as 0.5m for a channel width of 1m); the second group contains 3 low-frequency inserts, which are evenly spaced longitudinally along the cross-section of the channel (the spacing is adjusted according to the height of the channel, such as 0.4m for a channel height of 0.8m).

[0060] Second row: Completely repeat the design of the first row, with 2 pieces in the first group and 3 pieces in the second group, arranged in a cross pattern to maintain consistency;

[0061] All subsequent low-frequency arrangement units are arranged in a 2+3 combination until they reach the starting end of the mid-to-high frequency sound-absorbing insert 22, forming a regular and continuous low-frequency noise reduction section.

[0062] Other optional repeating combination patterns: If the channel cross-sectional size is large or the low-frequency noise energy is stronger, a 3+4 combination pattern can be used, that is, each arrangement unit is "Group 1 3 pieces (horizontal) + Group 2 4 pieces (vertical)," which is repeated continuously along the airflow direction;

[0063] The arrangement principle is to use only one fixed combination of a few or many pieces in the same scheme, and repeat the arrangement throughout the process to ensure uniform and stable low-frequency noise reduction effect, while simplifying the processing and installation process.

[0064] For example, the low-frequency sound-absorbing inserts 21 are arranged as follows: The first row unit (closest to the sound insulation test chamber 1): The first group contains 3 low-frequency inserts, which are evenly spaced laterally along the channel cross section (spacing 0.4m); The second group contains 5 low-frequency inserts, which are evenly spaced longitudinally along the channel cross section (spacing 0.2m).

[0065] The second arrangement unit: the first group contains 4 low-frequency inserts (horizontal spacing 0.3m), the second group contains 6 low-frequency inserts (vertical spacing 0.15m), and the insert coverage density is further increased after the cross arrangement;

[0066] The subsequent low-frequency arrangement units are repeated in an alternating pattern of 3+5, 4+6, 3+5, etc., until the low-frequency band arrangement is completed.

[0067] This embodiment adapts to the uneven noise energy characteristics within the channel, improving the accuracy of frequency band noise reduction: The noise energy distribution across the cross-section of exhaust channel 2 and along the airflow direction is not uniform (e.g., higher noise energy in the central area and lower noise energy at the edges). Combinations of fewer or more inserts within the same arrangement unit can specifically enhance the noise reduction effect in high-energy areas (more inserts increase the sound-absorbing contact area). Simultaneously, fewer inserts ensure smooth airflow in low-energy areas, avoiding uneven noise reduction or airflow obstruction caused by uniform density throughout the entire area, making the absorption of low-frequency and mid-to-high-frequency noise more targeted. The differentiated arrangement of inserts avoids regular reflections and resonances of sound waves within the channel, especially weakening the superposition and enhancement effect of low-frequency noise. Combined with the segmented layout upstream of low-frequency inserts and downstream of mid-to-high-frequency inserts, noise in different frequency bands can be efficiently absorbed. The front section of the passage near the sound insulation test chamber 1 is subjected to high sound pressure and strong vibration. The low-frequency sound-absorbing inserts 21, through differentiated arrangement, can reduce stress concentration in local areas and avoid deformation or damage of the inserts due to strong vibration. Similarly, the differentiated design of the mid- and high-frequency inserts can avoid directly bearing the concentrated impact of residual noise and extend the service life of the overall insert structure.

[0068] Furthermore, in one specific embodiment, the outer shells of both the low-frequency sound-absorbing insert 21 and the mid-to-high-frequency sound-absorbing insert 22 are perforated aluminum plates, and the sound-absorbing material filled inside is wrapped by a sound-permeable membrane; wherein, the thickness of the low-frequency sound-absorbing insert 21 along the airflow direction is greater than the thickness of the mid-to-high-frequency sound-absorbing insert 22 along the airflow direction.

[0069] Understandably, the front section of the channel near the test chamber experiences stronger acoustic vibrations, and the structural design of the low-frequency sound-absorbing insert 21 is more suitable for high sound pressure conditions. The mid-to-high frequency inserts are arranged in the rear section to avoid directly bearing the strong vibrations and high noise impacts of the front section, thus extending the lifespan of the inserts. At the same time, the segmented arrangement allows for targeted adjustment of the number and density of inserts according to the noise characteristics of different sections, ensuring sound attenuation while controlling costs.

[0070] Furthermore, in one specific embodiment, the exhaust channel 2 is provided with multiple bends in the gas flow direction.

[0071] This embodiment can extend the noise propagation path within a limited space, causing noise to reflect and collide multiple times at the bends, fully contacting the inner wall of the channel and the sound-absorbing inserts, further attenuating noise energy and improving the overall noise reduction effect. The bend structure can disrupt the directionality of noise propagation, reducing concentrated noise leakage. The bend design can avoid excessively high airflow velocity caused by straight inflow and outflow, reducing airflow noise generation, while ensuring 1000Nm 3 With a stable exhaust volume of / min, it balances heat dissipation and noise reduction. The bent structure can improve the overall rigidity of the exhaust channel 2, making it more suitable for the strong vibration conditions of high sound pressure test, reducing channel deformation and extending service life.

[0072] Example 4:

[0073] This application also provides device embodiments that follow the above embodiments. The interpretation of the same names is the same as that of the above embodiments, and they have the same technical effects as those of the above embodiments. They will not be described again here.

[0074] This application provides a noise silencing system for aircraft testing, including a high sound pressure test noise silencing device and an acoustic traveling wave tube according to any of the above embodiments, for generating high sound pressure test noise to perform high sound pressure level noise testing on the equipment under test housed in a soundproof test chamber.

[0075] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems or apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and relevant parts can be referred to the method section.

[0076] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A noise silencing device for high sound pressure level testing, characterized in that, The device includes: a sound insulation test chamber for accommodating the high sound pressure test equipment and connected to the sound-emitting component of the acoustic test equipment that generates high sound pressure noise; wherein the sound insulation test chamber is a sealed sound room structure, and the walls and roof of the sound insulation test chamber are made of sound insulation structure; an exhaust channel connected to the interior of the sound insulation test chamber for exhausting the air inside the sound insulation test chamber, and the exhaust channel is provided with sound-absorbing inserts.

2. The apparatus according to claim 1, characterized in that, The walls and roof of the sound insulation test chamber are both double-walled structures, with a cavity between the two wall layers.

3. The apparatus according to claim 2, characterized in that, The wall structure, from the inside to the outside of the sound insulation test chamber, includes galvanized steel plate, environmentally friendly sound-absorbing cotton, thick gypsum board, rubber damping, and galvanized steel plate.

4. The apparatus according to claim 2, characterized in that, At least one side of the wall inside the cavity is covered with environmentally friendly sound-absorbing cotton.

5. The apparatus according to claim 1, characterized in that, The sound insulation test chamber has sound-absorbing wedges on the walls and roof facing the sound-emitting components of the acoustic test equipment.

6. The apparatus according to claim 1, characterized in that, Multiple sets of low-frequency sound-absorbing inserts and multiple sets of mid-to-high-frequency sound-absorbing inserts are arranged sequentially in the gas flow direction of the exhaust channel. The low-frequency sound-absorbing inserts are closer to the sound insulation test chamber than the high-frequency sound-absorbing inserts. Each set of low-frequency sound-absorbing inserts includes multiple low-frequency sound-absorbing inserts, and each set of mid-to-high-frequency sound-absorbing inserts includes multiple mid-to-high-frequency sound-absorbing inserts. Both the low-frequency sound-absorbing inserts and the mid-to-high-frequency sound-absorbing inserts are arranged sequentially in the cross-sectional direction of the exhaust channel.

7. The apparatus according to claim 6, characterized in that, The low-frequency sound-absorbing inserts are arranged in pairs as a unit for airflow direction, and the two groups of low-frequency sound-absorbing inserts in the same unit contain different numbers of inserts; the mid-to-high frequency sound-absorbing inserts are arranged in pairs as a unit for airflow direction, and the two groups of mid-to-high frequency sound-absorbing inserts in the same unit contain different numbers of inserts.

8. The apparatus according to claim 6, characterized in that, The outer shells of both the low-frequency sound-absorbing insert and the mid-to-high-frequency sound-absorbing insert are perforated aluminum plates, and the sound-absorbing material inside is wrapped by a sound-permeable membrane; wherein, the thickness of the low-frequency sound-absorbing insert along the airflow direction is greater than the thickness of the mid-to-high-frequency sound-absorbing insert along the airflow direction.

9. The apparatus according to claim 1, characterized in that, The exhaust channel has multiple bends in the gas flow direction.

10. A noise reduction system for aircraft testing, characterized in that, The device includes a high sound pressure test noise silencing device and an acoustic traveling wave tube as described in any one of claims 1-9, for generating high sound pressure test noise to perform high sound pressure level noise testing on the equipment under test housed in the soundproof test chamber.

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