A porous core material arrangement structure of a sound absorption and noise reduction honeycomb panel

Abstract

The utility model provides a kind of porous core material arrangement structure of sound-absorbing and noise-reducing honeycomb board belongs to arrangement structure technical field, the porous core material arrangement structure of sound-absorbing and noise-reducing honeycomb board includes honeycomb substrate, porous sound-absorbing core body and corrugated flow guide layer, porous sound-absorbing core body is embedded in the hexagonal hole cavity inside honeycomb substrate, porous sound-absorbing core body is cylindrical structure and its axis is parallel with the thickness direction of honeycomb substrate, the annular airflow passage is formed between the outer circumferential surface of porous sound-absorbing core body and the inner wall surface of hexagonal hole cavity, corrugated flow guide layer is attached and is arranged in at least one side surface of honeycomb substrate, corrugated flow guide layer has multiple wave peak and wave trough alternate arrangement undulating structure, the top of wave peak is in contact with honeycomb substrate surface, and the bottom of wave trough and honeycomb substrate surface form flow guide gap, solve the problem that existing honeycomb board because only rely on cavity resonance leads to sound-absorbing band narrow, coefficient low, hole cavity has no sound energy dissipation structure, cannot satisfy the problem of high-noise environment broadband high-efficiency sound-absorbing demand.

Description

Technical Field

[0001] This utility model belongs to the field of layout structure technology, specifically, it relates to a porous core material layout structure for a sound-absorbing and noise-reducing honeycomb panel. Background Technology

[0002] In modern industrial production and daily life, noise pollution has become a significant factor affecting environmental quality and human health. Various noise sources, such as machinery operation noise, transportation noise, and construction noise, are widespread, making the need for effective control and management of these noises increasingly urgent. Honeycomb panels, as a lightweight and high-strength composite material structure, are widely used in sound absorption and noise reduction due to their unique porous cavity characteristics. Traditional honeycomb sound-absorbing panels mainly rely on the cavity resonance principle of the honeycomb pores to absorb sound energy. When sound waves are incident on the surface of the honeycomb panel, some sound energy enters the cavity, where reflection and interference occur on the cavity walls. Sound waves of specific frequencies resonate within the cavity and are absorbed. However, this sound absorption mechanism, which relies solely on cavity resonance, has significant limitations; the sound absorption band is typically narrow. Effective only near the resonant frequency, its absorption effect on broadband noise, especially mid-to-low frequency noise, is not ideal. To improve the sound absorption performance of honeycomb panels, various measures have been taken in the existing technology, including filling the honeycomb cavities with sound-absorbing cotton or foam materials, covering the surface of the honeycomb panel with perforated panels or fabric layers, and changing the shape and size of the honeycomb cavities. However, the filling material method will significantly increase the weight of the panel and affect its mechanical properties. Perforated panels or fabric layers are easy to clog and have poor durability. Simply changing the geometric parameters of the cavities makes it difficult to obtain a balanced sound absorption effect over a wide frequency range. Therefore, there is an urgent need to develop a new type of honeycomb panel sound absorption and noise reduction structure that can achieve high-efficiency sound absorption and noise reduction performance over a wide frequency range by optimizing the core material arrangement and acoustic structure design while maintaining the advantages of lightweight and high strength of honeycomb panels. Utility Model Content

[0003] In view of this, the present invention provides a porous core material arrangement structure for a sound-absorbing and noise-reducing honeycomb panel, which solves the problem that existing honeycomb panels rely solely on cavity resonance, resulting in a narrow sound absorption band and low coefficient, and the absence of sound energy dissipation structure in the pores, thus failing to meet the wide-band and high-efficiency sound absorption requirements in high-noise environments.

[0004] This utility model is implemented as follows:

[0005] This utility model provides a porous core material arrangement structure for a sound-absorbing and noise-reducing honeycomb panel, comprising a honeycomb substrate, a porous sound-absorbing core, and a corrugated flow guide layer. The porous sound-absorbing core is embedded inside the hexagonal cavity of the honeycomb substrate. The porous sound-absorbing core has a cylindrical structure and its axis is parallel to the thickness direction of the honeycomb substrate. An annular airflow channel is formed between the outer circumferential surface of the porous sound-absorbing core and the inner wall surface of the hexagonal cavity. The corrugated flow guide layer is attached to at least one side surface of the honeycomb substrate. The corrugated flow guide layer has an undulating structure with multiple alternating peaks and troughs. The top of the peaks contacts the surface of the honeycomb substrate, and the bottom of the troughs forms a flow guide gap with the surface of the honeycomb substrate.

[0006] The technical effects of the porous core material arrangement structure of the sound-absorbing and noise-reducing honeycomb panel provided by this utility model are as follows: By embedding the cylindrical porous sound-absorbing core into the hexagonal cavity of the honeycomb substrate and forming an annular airflow channel, the sound waves first undergo multiple reflections and refractions in the annular airflow channel after entering the cavity. The sound energy is gradually consumed in the irregular path of the airflow channel. At the same time, the undulating structure of the corrugated guide layer forms a guide gap on the surface of the honeycomb substrate. When the sound waves enter through the guide gap, a turbulence effect is generated, which further increases the sound energy loss. The synergistic effect of the porous sound-absorbing core and the annular airflow channel significantly improves the overall sound absorption and noise reduction performance. Compared with the traditional single cavity structure, it has a wider sound absorption band and a higher noise reduction coefficient.

[0007] Based on the above technical solution, the porous core material arrangement structure of the sound-absorbing and noise-reducing honeycomb panel of this utility model can be further improved as follows:

[0008] The porous sound-absorbing core has multiple longitudinally extending through holes evenly distributed on its cylindrical outer surface, and the through holes are arranged to penetrate along the axial direction of the porous sound-absorbing core.

[0009] The beneficial effects of the above-mentioned improvement scheme are as follows: the longitudinal through holes on the surface of the porous sound-absorbing core provide an additional propagation path for sound waves. After the sound waves enter the through holes, they undergo viscous friction and heat conduction loss on the inner wall of the channel. The longitudinal extension structure of the through holes greatly increases the propagation distance of the sound waves inside the core and prolongs the residence time of the sound waves in the porous medium, thereby improving the conversion efficiency of sound energy to heat energy. In particular, the absorption effect of mid-to-high frequency noise is significantly enhanced. At the same time, the uniform distribution of the through holes ensures the consistency of the sound absorption performance of the core in all directions.

[0010] Furthermore, the radial width of the annular airflow channel varies along the thickness direction of the honeycomb substrate, and the radial width of the annular airflow channel on the side closer to the corrugated guide layer is greater than the radial width on the side farther away from the corrugated guide layer.

[0011] The beneficial effects of adopting the above-mentioned improved scheme are as follows: the radial width of the annular airflow channel changes along the thickness direction to form a gradually changing acoustic impedance matching structure. When the sound wave enters from one side of the corrugated guide layer, it encounters a wider airflow channel, and the acoustic impedance changes more gradually, reducing the reflection loss of the sound wave at the entrance. As the sound wave propagates inward, the airflow channel gradually narrows, and the acoustic impedance gradually increases. The sound energy is more fully absorbed and converted in the gradually changing impedance environment. This non-uniform channel structure effectively broadens the sound absorption frequency range, especially improving the problem of insufficient low-frequency sound absorption performance.

[0012] Furthermore, the end face of the porous sound-absorbing core is circular, and the ratio of the diameter of the circular end face to the diameter of the inscribed circle of the hexagonal cavity is 0.6 to 0.85.

[0013] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: by controlling the diameter of the circular end face of the porous sound-absorbing core and the diameter of the inner circle of the hexagonal cavity within a specific ratio range, it is ensured that the annular airflow channel has a reasonable radial dimension. When the ratio is too small, the airflow channel is too wide, causing the sound wave to penetrate directly and reducing the sound absorption effect. When the ratio is too large, the airflow channel is too narrow, causing the sound wave to be obstructed and increasing reflection. This ratio range achieves the best matching relationship between the width of the airflow channel and the wavelength of the sound wave, so that sound waves of different frequencies can obtain sufficient energy attenuation in the airflow channel, and the overall sound absorption performance reaches the optimal state.

[0014] Furthermore, the wave crests of the corrugated flow guide layer are convex in shape, the wave troughs are concave in shape, and the wavelength between two adjacent wave crests is equal to the distance between opposite sides of the hexagonal cavity of the honeycomb substrate.

[0015] The beneficial effects of adopting the above-mentioned improved scheme are as follows: the convex and concave shapes of the corrugated flow guide layer cause continuous curved surface scattering when sound waves are incident, and the sound wave energy is dispersed to multiple directions rather than concentrated reflection. The contact between the wave crest and the surface of the honeycomb substrate provides stable support and conduction path. The design that the wavelength is equal to the distance between opposite sides of the hexagonal cavity ensures that each cavity corresponds to a complete corrugation cycle. After the sound waves pass through the corrugated structure, they can be evenly distributed to the interior of each cavity, avoiding the phenomenon of local cavity sound absorption overload or idleness, and significantly improving the overall sound absorption utilization rate and uniformity of the honeycomb panel.

[0016] Furthermore, the through holes on the porous sound-absorbing core are arranged in a spiral pattern, and the spirally distributed through holes extend around the axis of the porous sound-absorbing core, with the circumferential spacing between adjacent through holes gradually decreasing along the axial direction.

[0017] The beneficial effects of the above-mentioned improved scheme are as follows: the spiral distribution of through holes on the porous sound-absorbing core creates a spiral propagation path for sound waves inside the core. As the sound waves travel along the spiral trajectory, they continuously change their propagation direction and consume more energy through repeated collisions with the inner walls of the through holes. The design of the circumferential spacing between adjacent through holes decreasing along the axial direction further increases the complexity of the sound wave propagation path. The sound waves encounter a denser distribution of through holes deep within the core, and the sound absorption efficiency increases with depth. This spiral decreasing structure is particularly suitable for handling broadband noise and can provide effective attenuation for different frequency components.

[0018] Furthermore, the depth of the flow guide gap in the corrugated flow guide layer varies periodically along the surface of the honeycomb substrate, and the depth of the flow guide gap at the center of the hexagonal cavity is greater than the depth at the edge of the hexagonal cavity.

[0019] The beneficial effects of adopting the above-mentioned improved scheme are as follows: the periodic change in the depth of the corrugated guide layer creates a non-uniform acoustic impedance distribution on the surface of the honeycomb panel. When the sound wave is incident at different positions, it encounters different impedance characteristics. The deeper guide gap at the center of the hexagonal cavity provides a larger sound wave buffer space, where the sound wave energy is initially dissipated. The shallower gap at the edge guides the sound wave to quickly enter the annular airflow channel. This distribution pattern of deep center and shallow edge optimizes the energy distribution of the sound wave at the cavity entrance, reduces the direct penetration and edge diffraction of the sound wave, and significantly improves the overall sound absorption efficiency.

[0020] Furthermore, the porous sound-absorbing core is made of porous ceramic material or porous metal foam material, and the honeycomb substrate is made of aluminum alloy material.

[0021] The beneficial effects of adopting the above-mentioned improved scheme are as follows: porous ceramic materials or porous metal foam materials have a large number of open micropore structures. When sound waves propagate inside these micropores, they generate strong viscous friction and thermal conduction effects, and sound energy is quickly converted into heat energy and absorbed. The aluminum alloy honeycomb substrate provides a lightweight and high-strength support frame, which minimizes the self-weight of the board while ensuring structural strength. The combination of porous sound-absorbing material and metal honeycomb frame achieves the best balance between sound absorption performance and mechanical properties, which is suitable for applications with strict requirements on weight and strength. At the same time, the durability and stability of the material are also fully guaranteed.

[0022] Furthermore, the two end faces of the porous sound-absorbing core are respectively flush with the upper and lower opening end faces of the honeycomb substrate, and the porous sound-absorbing core is fixed inside the hexagonal cavity by interference fit.

[0023] The beneficial effects of the above-mentioned improvement scheme are as follows: the flush setting of the two ends of the porous sound-absorbing core with the opening end of the honeycomb substrate eliminates the steps or gaps between the core end and the board surface. When sound waves are incident from both sides of the board, they can smoothly enter the porous core and the annular airflow channel, avoiding sound wave reflection and energy loss caused by uneven end faces. The interference fit fixing method achieves a tight bond between the core and the cavity without the use of additional adhesives. The fitting force ensures that the core will not loosen or fall off under vibration. At the same time, the radial pressure generated by the interference fit creates good acoustic coupling between the core and the cavity wall, further enhancing the sound energy transmission and absorption effect.

[0024] Furthermore, the corrugated flow guide layer is bonded and fixed to the surface of the honeycomb substrate by an adhesive layer. The thickness of the adhesive layer is uniformly distributed in the contact area between the top of the corrugation and the surface of the honeycomb substrate. The material of the corrugated flow guide layer is a polyester fiber composite material.

[0025] The beneficial effects of adopting the above-mentioned improved scheme are as follows: the corrugated flow guide layer is bonded to the surface of the honeycomb substrate only at the top of the corrugations through the adhesive layer. This point contact fixing method ensures the connection strength while maximizing the flow guide gap space of the corrugated structure. The uniform distribution of the adhesive layer thickness ensures that each corrugation is subjected to balanced force, avoiding bonding failure caused by local stress concentration. The polyester fiber composite material has good flexibility and damping characteristics. The corrugated flow guide layer itself can also absorb some sound energy and suppress the vibration of the board. Together with the porous sound-absorbing core and the honeycomb substrate, it forms a triple sound absorption and noise reduction system, and the overall noise reduction performance reaches the optimal level.

[0026] Compared with existing technologies, the beneficial effects of the porous core material arrangement structure of the sound-absorbing and noise-reducing honeycomb panel provided by this utility model are as follows: This utility model, by embedding a cylindrical porous sound-absorbing core in the hexagonal cavity of the honeycomb substrate and forming an annular airflow channel, combined with the undulating structure of the corrugated guide layer, constructs a multi-level, multi-mechanism sound energy dissipation system. Sound waves first undergo scattering and guiding effects through the corrugated guide layer, generating turbulent loss within the guide gaps. Then, they enter the annular airflow channel for multiple reflections and refractions, and finally, absorption is achieved through viscous friction and thermal conduction in the microporous structure of the porous sound-absorbing core. The synergistic effect of the three sound absorption mechanisms enables this utility model to maintain a high sound absorption coefficient in a wide frequency range from 100 Hz to 5000 Hz, effectively broadening the sound absorption band by 60° compared to existing technologies. The absorption capacity is significantly enhanced, especially for low-to-mid frequency noise in the 300 Hz to 800 Hz range. The gradually changing acoustic impedance matching structure of the annular airflow channel reduces sound wave reflection loss at the entrance, improving the efficiency of sound energy entering the interior of the board. The spirally distributed through holes on the porous sound-absorbing core increase the length and complexity of the sound wave propagation path, prolonging the sound energy attenuation time. The periodic gap depth variation of the corrugated guide layer optimizes the energy distribution of sound waves between various cavities, avoiding local sound absorption saturation. The overall structure achieves excellent broadband and efficient sound absorption and noise reduction performance while maintaining lightweight and high strength characteristics. The porous ceramic or metal foam and aluminum alloy honeycomb frame used are mature and well-known materials. The manufacturing process is simple and cost-controllable, making it suitable for large-scale industrial production and widespread application. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 An example diagram of a porous core material arrangement structure for a sound-absorbing and noise-reducing honeycomb panel;

[0029] Figure 2 A front view of a porous core material arrangement structure of a sound-absorbing and noise-reducing honeycomb panel;

[0030] The attached diagram lists the components represented by each number as follows:

[0031] 10. Honeycomb substrate; 11. Adhesive layer; 20. Porous sound-absorbing core; 30. Corrugated flow guiding layer. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0033] like Figure 1 , Figure 2 The diagram shown is an example of a porous core material arrangement structure of a sound-absorbing and noise-reducing honeycomb panel provided by this utility model. It includes a honeycomb substrate 10, a porous sound-absorbing core 20, and a corrugated flow guide layer 30. The porous sound-absorbing core 20 is embedded in the hexagonal cavity of the honeycomb substrate 10. The porous sound-absorbing core 20 has a cylindrical structure and its axis is parallel to the thickness direction of the honeycomb substrate 10. An annular airflow channel is formed between the outer circumferential surface of the porous sound-absorbing core 20 and the inner wall surface of the hexagonal cavity. The corrugated flow guide layer 30 is attached to at least one side surface of the honeycomb substrate 10. The corrugated flow guide layer 30 has an undulating structure with multiple alternating peaks and troughs. The top of the peaks contacts the surface of the honeycomb substrate 10, and the bottom of the troughs forms a flow guide gap with the surface of the honeycomb substrate 10.

[0034] The specific operation or usage method is as follows: The prepared porous sound-absorbing cores are pressed one by one into the hexagonal cavities of the honeycomb substrate using an interference fit, ensuring that the cylindrical outer surface of the core is in close contact with the inner wall of the cavity, and that both ends of the core are flush with the upper and lower opening ends of the honeycomb substrate, forming a stable annular airflow channel structure. Then, adhesive is evenly coated on one or both surfaces of the honeycomb substrate. The crest of the corrugated flow guide layer is aligned with the surface of the honeycomb substrate and bonded together. Appropriate pressure is applied to ensure a uniform thickness of the adhesive layer. After curing, a strong bond is formed. The assembled sound-absorbing and noise-reducing honeycomb panel is installed at the location requiring noise reduction, with the panel facing the noise source. Sound waves are incident from one side of the corrugated flow guide layer. In actual use, when environmental noise propagates to the surface of the honeycomb panel in the form of sound waves, the corrugated flow guide layer first scatters and diverts the sound waves. Sound waves enter the hexagonal cavities through the guide gaps. After multiple reflections and refractions within the annular airflow channel, some sound waves enter the longitudinal through-holes and internal microporous structure of the porous sound-absorbing core, completing the final energy absorption and conversion within the porous medium. The entire sound absorption process requires no external power or control system, relying entirely on the natural attenuation of the sound wave's own energy within the special structure. For noise of different frequencies, low-frequency sound waves, due to their longer wavelengths, are mainly absorbed in the gradually varying impedance structure of the annular airflow channel. Mid-frequency sound waves dissipate through viscous friction in the through-holes and microporous network, while high-frequency sound waves attenuate rapidly through multiple scatterings on the corrugated guide layer and the core surface. During use, the surface of the corrugated guide layer should be checked regularly for dust or foreign objects blocking the guide gaps. If necessary, it should be cleaned by blowing with airflow or wiping with a soft cloth to keep the guide channel unobstructed and maintain optimal sound absorption performance.

[0035] In the above technical solution, a plurality of longitudinally extending through holes are evenly distributed on the cylindrical outer surface of the porous sound-absorbing core 20, and the through holes are arranged to penetrate along the axial direction of the porous sound-absorbing core 20.

[0036] Furthermore, in the above technical solution, the radial width of the annular airflow channel varies along the thickness direction of the honeycomb substrate 10, and the radial width of the annular airflow channel on the side closer to the corrugated guide layer 30 is greater than the radial width on the side farther from the corrugated guide layer 30.

[0037] Furthermore, in the above technical solution, the end face of the porous sound-absorbing core 20 is circular, and the ratio of the diameter of the circular end face to the diameter of the inscribed circle of the hexagonal cavity is 0.6 to 0.85.

[0038] Furthermore, in the above technical solution, the peaks of the corrugated flow guide layer 30 are in the shape of a circular arc protrusion, and the troughs are in the shape of a circular arc concavity. The wavelength between two adjacent peaks is equal to the distance between opposite sides of the hexagonal cavity of the honeycomb substrate 10.

[0039] Furthermore, in the above technical solution, the through holes on the porous sound-absorbing core 20 are arranged in a spiral pattern. The spirally distributed through holes extend around the axis of the porous sound-absorbing core 20, and the circumferential spacing between adjacent through holes gradually decreases along the axial direction.

[0040] Furthermore, in the above technical solution, the distribution of the flow guide gap depth of the corrugated flow guide layer 30 along the surface of the honeycomb substrate 10 varies periodically, and the depth of the flow guide gap at the center of the hexagonal cavity is greater than the depth at the edge of the hexagonal cavity.

[0041] Furthermore, in the above technical solution, the porous sound-absorbing core 20 is made of porous ceramic material or porous metal foam material, and the honeycomb substrate 10 is made of aluminum alloy material.

[0042] Furthermore, in the above technical solution, the two end faces of the porous sound-absorbing core 20 are respectively flush with the upper and lower open end faces of the honeycomb substrate 10, and the porous sound-absorbing core 20 is fixed inside the hexagonal cavity by interference fit.

[0043] Furthermore, in the above technical solution, the corrugated flow guide layer 30 is bonded and fixed to the surface of the honeycomb substrate 10 by an adhesive layer 11. The thickness of the adhesive layer 11 is evenly distributed in the contact area between the top of the corrugation and the surface of the honeycomb substrate 10. The material of the corrugated flow guide layer 30 is a polyester fiber composite material.

[0044] Specific Embodiment 1: In this embodiment, the honeycomb substrate is made of aluminum alloy, specifically 3003 aluminum alloy sheet. A hexagonal cavity array structure is formed through a honeycomb core stretching process. The distance between opposite sides of each hexagonal cavity is 12mm, the cavity wall thickness is 0.08mm, the overall thickness of the honeycomb substrate is 25mm, and the honeycomb density is 80 cavities per square meter. The aluminum alloy honeycomb substrate is lightweight and high-strength, with a unit area weight of only 1.5kg per square meter. It also has good corrosion resistance and processing performance. The porous sound-absorbing core is made of porous alumina ceramic material with a porosity of 45% and an average pore diameter of 80 micrometers. It is formed into a cylindrical core with a diameter of 8mm through an extrusion molding process, and the core length is... The core, with a thickness equal to 25mm and the honeycomb substrate, has six longitudinal through-holes evenly drilled on its cylindrical outer surface. Each through-hole has a diameter of 1.2mm and penetrates the core along its axial direction. The six through-holes are evenly distributed along the outer circumference of the core, with a central angle of 60 degrees between adjacent holes. The porous ceramic core has a density of 1.8 grams per cubic centimeter and exhibits excellent high-temperature resistance and sound absorption properties. The porous sound-absorbing core is pressed into the hexagonal cavity of the honeycomb substrate using an interference fit, with the interference controlled between 0.2mm and 0.3mm to ensure a tight fit between the core and the cavity wall. The end face of the core is flush with the open end face of the honeycomb substrate. At this point, an annular airflow channel is formed between the outer circumferential surface of the core and the inner wall of the hexagonal cavity. The radial width of the channel is close to the corrugated guide... The corrugated flow guide layer has a thickness of 2.5mm on one side and 1.8mm on the side away from the corrugated flow guide layer, exhibiting a gradual change along the thickness direction. The corrugated flow guide layer is made of polyester fiber composite material with a thickness of 0.5mm. It is formed into an undulating structure with alternating peaks and troughs through a hot-pressing process. The peaks are arc-shaped convex shapes with an arc radius of 8mm and a peak height of 3mm. The troughs are arc-shaped concave shapes with a depth of 3mm. The wavelength between two adjacent peaks is 12mm, which is exactly equal to the distance between opposite sides of the hexagonal cavities of the honeycomb substrate. Thus, each hexagonal cavity corresponds to a complete corrugation cycle. A 0.1mm thick epoxy resin adhesive layer is coated between the top of the peaks and the surface of the honeycomb substrate to firmly bond the corrugated flow guide layer to the honeycomb substrate. A 2.9mm deep flow guide gap is formed between the bottom of the trough and the surface of the honeycomb substrate. The flow guide gap depth remains at 2.9mm above the center of the hexagonal cavity, while above the edge of the cavity, the flow guide gap depth gradually decreases to about 1.5mm due to the arc transition of the crest, forming a periodically varying depth distribution. The assembled sound-absorbing and noise-reducing honeycomb panel has a total thickness of 28.5mm and a unit area weight of 2.3kg per square meter, maintaining its lightweight characteristics. In acoustic testing, the honeycomb panel is installed in a standing wave tube testing device with the corrugated flow guide surface facing the sound source. The test frequency range is 100Hz to 5000Hz. The results show that the average sound absorption coefficient reaches 0 in a wide frequency range of 200Hz to 4500Hz.Above 75, in the mid-frequency range of 800 Hz to 2000 Hz, the peak sound absorption coefficient reaches 0.92, demonstrating excellent wideband and high-efficiency sound absorption performance. After being scattered and guided by the corrugated guide layer, the sound waves undergo multiple reflections within the annular airflow channel. The gradually changing width design of the channel ensures a smooth transition in acoustic impedance, reducing inlet reflection loss. After entering the longitudinal through-holes and internal microporous network of the porous ceramic core, the sound waves are finally absorbed under the action of viscous friction and thermal conduction. The synergistic effect of this triple sound absorption mechanism ensures stable and efficient noise reduction across a wide frequency band.

[0045] Specific Embodiment 2: This Embodiment 2 is based on Embodiment 1, but the longitudinal through holes on the porous sound-absorbing core are changed to a spiral arrangement. Specifically, eight through holes are set on the outer surface of the cylindrical core. These eight through holes are no longer arranged parallel along the axial direction, but are arranged in a spiral rotation around the core axis. The pitch of the spiral is 15mm. The initial through hole is located at the upper end face of the core, and the holes are distributed downwards along the spiral. The circumferential distance between adjacent through holes is 50 degrees at the upper part of the core, gradually decreasing to 40 degrees in the middle part of the core, and further decreasing to 30 degrees at the lower part of the core, showing a decreasing distribution characteristic along the axial direction. The diameter of the through holes remains unchanged at 1.2mm. This spiral decreasing arrangement of through holes allows the sound waves to form a three-dimensional spiral propagation path inside the porous sound-absorbing core. After entering the upper through hole, the sound waves propagate downwards along the spiral trajectory, continuously changing... The design of changing direction and colliding and rubbing against the wall of the through holes, and the decreasing circumferential spacing of adjacent through holes, allows sound waves to encounter a denser distribution of through holes deep within the core. The sound absorption efficiency gradually increases with depth, the complexity of the sound wave propagation path increases significantly, the residence time in the ceramic microporous network is extended, and the conversion of sound energy into heat energy is more complete. Acoustic test results show that the honeycomb panel with a spiral decreasing through hole distribution has an average sound absorption coefficient of 0.82 across the entire frequency band from 100 Hz to 5000 Hz, which is about 9 percentage points higher than that of Example 1. In particular, for mid-to-low frequency noise from 300 Hz to 600 Hz, the sound absorption coefficient has increased from 0.68 in Example 1 to 0.79, showing a significant improvement. The spiral through hole structure is more adaptable to complex broadband noise and is suitable for applications with a wide frequency spectrum, such as mechanical equipment noise and traffic noise.

[0046] Specifically, the principle of this utility model is as follows: The core of this utility model lies in constructing a multi-level impedance matching and energy dissipation system along the sound wave propagation path through the annular airflow channel formed between the porous sound-absorbing core and the cavity of the honeycomb substrate, and the undulating structure of the corrugated guide layer. When a sound wave is incident from external space onto the surface of the honeycomb panel, it first encounters the alternating peaks and troughs of the corrugated guide layer. The arc-shaped convex surface of the peaks scatters the sound wave, dispersing it in different directions and reducing specular reflection energy. The guide gaps formed by the troughs provide a channel for the sound wave to enter the cavity. The sound wave generates turbulence within the guide gaps due to abrupt spatial changes. The acoustic energy is converted into heat energy here. After passing through the corrugated guide layer, the sound waves enter the hexagonal cavity of the honeycomb substrate. Because the porous sound-absorbing core is cylindrical and located at the center of the cavity, the sound waves cannot penetrate directly but are forced into the annular airflow channel. In the annular channel, the sound waves propagate along the annular space between the outer circumference of the core and the inner wall of the cavity, undergoing multiple reflections and diffractions. Each interaction with the wall surface results in energy loss. The gradually changing radial width of the annular airflow channel causes the sound waves to gradually encounter increasing acoustic impedance during propagation. This smooth transition of impedance avoids strong reflections at abrupt interfaces, improving the transmittance and absorption rate of sound energy. At the same time, the surface of the porous sound-absorbing core... The longitudinal through-holes provide a path for sound waves to enter the core. As the sound waves propagate within these through-holes, they experience viscous friction against the pore walls. The vibrational energy of air molecules is transferred to the core material through heat conduction. Porous ceramic or metal foam materials contain numerous micron-sized open pores. The propagation path of sound waves after entering these micropores is extremely complex, involving continuous collisions and friction within the micropore network. Sound energy is efficiently converted into heat energy and dissipated. The spirally distributed through-holes create a three-dimensional spiral propagation trajectory for the sound waves within the core, further increasing energy loss. The periodic variation in the depth of the corrugated guide layer's guide gaps modulates the sound pressure distribution on the honeycomb panel surface. The deeper gaps provide a larger acoustic volume, similar to the cavity of a Helmholtz resonator, which can absorb sound waves of specific frequencies. The shallower gaps at the edges accelerate the introduction of sound waves into the annular channel. This non-uniform distribution optimizes the absorption efficiency of each frequency component at different locations. Through the synergistic effect of the above multiple mechanisms, this invention achieves efficient absorption of broadband noise. After the sound wave energy is attenuated step by step through multiple stages such as scattering by the corrugated guide layer, turbulent loss in the guide gap, multiple reflections in the annular airflow channel, viscous friction of the porous core, and microporous absorption, the transmitted and reflected sound energy is greatly reduced, thereby achieving excellent sound absorption and noise reduction effects.

Claims

1. A porous core material arrangement structure for a sound-absorbing and noise-reducing honeycomb panel, characterized in that, The device includes a honeycomb substrate, a porous sound-absorbing core, and a corrugated flow guide layer. The porous sound-absorbing core is embedded inside the hexagonal cavities of the honeycomb substrate. The porous sound-absorbing core has a cylindrical structure and its axis is parallel to the thickness direction of the honeycomb substrate. An annular airflow channel is formed between the outer circumferential surface of the porous sound-absorbing core and the inner wall surface of the hexagonal cavities. The corrugated flow guide layer is attached to at least one side surface of the honeycomb substrate. The corrugated flow guide layer has an undulating structure with multiple alternating peaks and troughs. The top of the peaks contacts the surface of the honeycomb substrate, and the bottom of the troughs forms a flow guide gap with the surface of the honeycomb substrate.

2. The porous core material arrangement structure of a sound-absorbing and noise-reducing honeycomb panel according to claim 1, characterized in that, The porous sound-absorbing core has multiple longitudinally extending through holes evenly distributed on its cylindrical outer surface, and the through holes are arranged to penetrate along the axial direction of the porous sound-absorbing core.

3. The porous core material arrangement structure of a sound-absorbing and noise-reducing honeycomb panel according to claim 2, characterized in that, The radial width of the annular airflow channel varies along the thickness direction of the honeycomb substrate, and the radial width of the annular airflow channel on the side closer to the corrugated guide layer is greater than the radial width on the side farther away from the corrugated guide layer.

4. The porous core material arrangement structure of a sound-absorbing and noise-reducing honeycomb panel according to claim 3, characterized in that, The end face of the porous sound-absorbing core is circular, and the ratio of the diameter of the circular end face to the diameter of the inscribed circle of the hexagonal cavity is 0.6 to 0.

85.

5. The porous core material arrangement structure of a sound-absorbing and noise-reducing honeycomb panel according to claim 4, characterized in that, The wave crests of the corrugated flow guide layer are convex in shape, and the wave troughs are concave in shape. The wavelength between two adjacent wave crests is equal to the distance between opposite sides of the hexagonal cavity of the honeycomb substrate.

6. The porous core material arrangement structure of a sound-absorbing and noise-reducing honeycomb panel according to claim 5, characterized in that, The through holes on the porous sound-absorbing core are arranged in a spiral pattern. The spirally distributed through holes extend around the axis of the porous sound-absorbing core, and the circumferential spacing between adjacent through holes gradually decreases along the axial direction.

7. The porous core material arrangement structure of a sound-absorbing and noise-reducing honeycomb panel according to claim 6, characterized in that, The depth of the flow guide gap in the corrugated flow guide layer varies periodically along the surface of the honeycomb substrate, and the depth of the flow guide gap at the center of the hexagonal cavity is greater than the depth at the edge of the hexagonal cavity.

8. The porous core material arrangement structure of a sound-absorbing and noise-reducing honeycomb panel according to claim 7, characterized in that, The porous sound-absorbing core is made of porous ceramic material or porous metal foam material, and the honeycomb substrate is made of aluminum alloy material.

9. The porous core material arrangement structure of a sound-absorbing and noise-reducing honeycomb panel according to claim 8, characterized in that, The two ends of the porous sound-absorbing core are flush with the upper and lower opening ends of the honeycomb substrate, respectively, and the porous sound-absorbing core is fixed inside the hexagonal cavity by interference fit.

10. The porous core material arrangement structure of a sound-absorbing and noise-reducing honeycomb panel according to claim 9, characterized in that, The corrugated flow guide layer is bonded and fixed to the surface of the honeycomb substrate by an adhesive layer. The thickness of the adhesive layer is evenly distributed in the contact area between the top of the corrugation and the surface of the honeycomb substrate. The material of the corrugated flow guide layer is a polyester fiber composite material.

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