28 results about "Helmholtz resonator" patented technology

This invention discloses a broadband duct silencing structure combining perforated tubes and cavities. The structure uses a galvanized housing as its main body, with perforated tubes coaxially arranged inside. A perforated partition divides the structure into front and rear silencing chambers. The front silencing chamber contains a first sound absorber and an air layer, forming a Helmholtz resonant cavity to efficiently eliminate low-frequency fan noise. The rear silencing chamber is filled with a second sound absorber and is equipped with perforated tubes, micro-perforated tubes, and micro-perforated inserts with progressively smaller apertures, forming a gradient microporous structure to achieve broadband absorption of mid-to-high frequency noise. The structure utilizes the airflow in the duct to drive the impeller to rotate, which in turn drives a bidirectional reciprocating screw via bevel gear transmission. This drives a delivery rod and a one-way valve to form a directional airflow circulation. The sound absorber is automatically purged through the air duct and comb-shaped air duct to remove fiber dust, preventing secondary pollution and stabilizing acoustic performance. This invention combines the advantages of low-frequency resonance silencing and mid-to-high frequency gradient microporous sound absorption, featuring a compact structure, wide silencing bandwidth, and stable and reliable operation.

This invention provides a multi-layered lightweight sound-absorbing and insulating material, comprising a layer of sound-absorbing cotton, a cup-shaped plastic film layer, and a plastic board layer stacked together. Multiple cup-shaped structures are arranged in an array on the cup-shaped plastic film layer. Each cup-shaped structure has a second through-hole at its bottom, and these structures are arranged periodically according to the size of the second through-hole. Within each arrangement cycle, there are multiple second through-holes with different diameters. The cup-shaped structures corresponding to the different diameters of the second through-holes form multiple Helmholtz resonators with different resonance frequencies. This invention forms multiple Helmholtz resonators with different resonance frequencies through multiple cup-shaped structures with different through-hole diameters. The coupling effect of the perforated cup-shaped structures with different resonance frequencies generates a continuous and wide mid-to-low frequency resonant sound-absorbing band. While possessing a certain high-frequency sound absorption capability, it significantly improves the low-to-mid frequency sound absorption and insulation capability. Compared with traditional porous sound-absorbing materials such as felt fibers and sound-absorbing cotton, it greatly improves the sound absorption and insulation capability at the same thickness.

This application discloses a broadband sound absorption structure for an air conditioner compressor, comprising: a carrier; multiple sound-absorbing units arranged in a matrix on the carrier; each sound-absorbing unit having multiple sound-absorbing cavities spaced apart and sound-absorbing holes formed on the surface of each sound-absorbing cavity; multiple sound-absorbing holes of the same sound-absorbing unit being on the same horizontal line and the hole size gradually increasing from one side to the other; and the hole wall of each sound-absorbing hole extending towards the sound-absorbing cavity; through the matrix arrangement of sound-absorbing units and their hole size gradient design, a multi-band Helmholtz resonant cavity is formed, utilizing the resonant frequency difference corresponding to different hole sizes to cover broadband sound absorption requirements from low frequency (80Hz) to high frequency (8000Hz); at the same time, the regular matrix arrangement enhances the sound wave scattering effect, increasing the sound absorption bandwidth by about 60% compared to traditional structures.

The utility model provides a gear acoustic metamaterial structure for wide band noise reduction, include: bottom plate and set up on the acoustic metamaterial unit of bottom plate, acoustic metamaterial unit includes several layers of resonant cavity, and resonant cavity is different section radius and coaxial setting's cylinder cavity respectively, the outer wall of each layer resonant cavity is provided with the opening of vertical through -penetration respectively, the inner wall of the resonant cavity of outermost layer and the outer wall of other resonant cavity are provided with gear structure respectively, the utility model discloses first introduce multilayer gear shape resonant cavity to acoustic metamaterial, and the gear -like structure is strengthened sound wave reflection and energy dissipation to break through the performance limit of traditional helmholtz resonator.

This invention discloses a porous Helmholtz resonator with adaptively adjustable sound absorption frequency band, belonging to the fields of noise control and virtual reality technology. It comprises a sound-absorbing structure consisting of a rotating perforated panel, a fixed perforated panel, and a perforated porous material plate arranged sequentially from top to bottom, as well as an adaptive adjustment system composed of a sound pressure sensor, a controller, and a motor. The motor drives the rotating perforated panel to rotate via gear transmission, changing the perforation overlap area; the perforated porous material plate compensates for acoustic impedance, maintaining sound absorption performance. The controller pre-stores spectral data at different rotation angles and selects the optimal rotation angle by comparing the real-time noise spectrum with the pre-stored data. This invention achieves adaptive adjustment of the sound absorption frequency band, maintains a high sound absorption peak value over a wide parameter range, is suitable for large-area deployment, has a compact structure, and low cost, and can be used for noise control and auditory virtual scenes.

An acoustic absorption assembly and a fan device, the acoustic absorption assembly is detachably arranged on the fan and includes a first plate member and a second plate member. The first plate member is arranged on the fan in a detachable manner and includes a plurality of first acoustic absorption structures. Each of the plurality of first acoustic absorption structures includes a first sound transmission slot, at least one first acoustic absorption slot, and at least one first neck passage. The at least one first acoustic absorption slot is communicated with the first sound transmission slot through the at least one first neck passage. The second plate member is detachably arranged on the first plate member and includes a plurality of second acoustic absorption structures. Each of the plurality of second acoustic absorption structures includes a second sound transmission slot, at least one second acoustic absorption slot, and at least one second neck passage. The at least one second acoustic absorption slot is communicated with the second sound transmission slot through the at least one second neck passage. The plurality of first acoustic absorption structures correspond to the plurality of second acoustic absorption structures respectively, and together form a plurality of Helmholtz resonance acoustic absorption cavities.

The application provides a double Helmholtz resonator device based on a friction nanogenerator, relates to the technical field of sound energy collection and comprises a front Helmholtz resonator chamber and a rear Helmholtz resonator chamber which are identical in shape, are hollow table-shaped structures with narrow upper surfaces and wide lower surfaces, and are symmetrically arranged with the upper surface of the front Helmholtz resonator chamber being connected with the lower surface of the rear Helmholtz resonator chamber; a groove structure is arranged on the upper surface of the rear Helmholtz resonator chamber, and a friction nanogenerator is arranged in the groove structure; and a porous plate is connected to the lower surfaces of the front Helmholtz resonator chamber and the rear Helmholtz resonator chamber, and a plurality of hole structures penetrating through the porous plate are arranged on the porous plate. The application adopts a sound energy collection technology based on a double Helmholtz resonator structure of the friction nanogenerator. Through the symmetric design of the double Helmholtz resonators, more stable sound energy collection is achieved.

This invention belongs to the field of noise-induced tinnitus protection technology, specifically disclosing a noise-induced tinnitus protection device, including protective earmuffs, a headband, and an adaptive acoustic adjustment device. It achieves "precise targeting" of harmful noise through a Helmholtz resonant cavity array and innovatively introduces a volume adaptive adjustment mechanism, allowing the silencing frequency to dynamically match the individual and the environment. Furthermore, it combines a reed-non-Newtonian fluid coupling intelligent response unit to achieve real-time changes in acoustic impedance with noise intensity, realizing dynamic and adaptive secondary silencing. The entire device requires no electricity, ensuring wideband noise reduction while effectively attenuating key frequency bands that induce tinnitus, providing a comfortable, intelligent, and reliable active hearing protection solution from the root cause.

This invention provides a gradient helical tube composite Helmholtz resonator sound absorption device and its adjustment method, relating to the field of noise control technology. It solves the problem of existing technologies' difficulty in simultaneously achieving high low-frequency efficiency and broadband sound absorption within a limited space. The gradient helical tube composite Helmholtz resonator sound absorption device includes a gradient helical tube and multiple Helmholtz resonator units. The diameter of the gradient helical tube changes continuously along the sound wave propagation path. The multiple Helmholtz resonator units are connected in series at the ends of the gradient helical tube and disposed within the internal space enclosed by the gradient helical tube. This invention can broaden the sound absorption bandwidth and enhance low-frequency sound absorption performance through the composite structure of the gradient helical tube and multiple Helmholtz resonator units.

An aperture (14) of an air duct (8) of an air conditioning system (6) of an aircraft (2) comprises a base body (16) and at least one channel (18a-e) in the base body (16), wherein the aperture (14) is acoustically optimized with respect to flow noise during operation (B) by the following variants: a channel (18a-e) has a tapered funnel shape (24a,b), and / or a channel (18a-e) has a lateral opening (32) with an adjacent cavity (34) forming a Helmholtz resonator, and / or an outlet end (28) of a channel (18a-e) is a free end (46) with a sawtooth structure (30) surrounding the channel (18a-e), and / or a slot-shaped channel (18a-e) has a consistently constant cross-section (38), and / or a channel (18a-e) has a circular, elliptical, or elongated hole-shaped cross-section, and / or an upstream end face (42) of the base body (16) bears tapered pointed forms (44) in the opposite direction of the flow (10). A duct arrangement (50) includes the air duct (8) with baffles (14) in the assembly state (M).

This invention discloses a composite sound-absorbing structure based on acoustic black holes, comprising multiple coplanar acoustic black hole units containing nested Helmholtz resonators. Each unit includes multiple perforated plates connected in series and a Helmholtz resonator with a nested cavity connected to its end. This composite structure increases the equivalent acoustic cavity length through the nested cavity, significantly enhancing low-frequency sound absorption performance below 200Hz, achieving excellent subwavelength sound absorption characteristics while maintaining a compact thickness. Through parameter optimization of the unit coplanarity and target frequency band, the total thickness at the 86Hz sound absorption peak is approximately λ / 50, and an average sound absorption coefficient of 0.8604 within the 226–1000Hz range can be achieved with a total thickness of less than 70 mm. The nested cavity design improves acoustic control flexibility, enabling precise control of complex low-frequency broadband noise. It possesses advantages such as small size, wide bandwidth, and strong low-frequency absorption, making it suitable for high-end noise control fields such as aerospace and shipbuilding, with broad application prospects.

This invention discloses a mid-to-low frequency ventilation and sound insulation metamaterial comprising two main areas: sound absorption and ventilation. The sound absorption area is divided into inner and outer rings, each composed of multiple circumferentially arranged sound-absorbing functional cavities. Each functional cavity includes a resonant cavity formed by partitions and a perforated cavity formed by micro-perforated plates. The perforations on the plates are positioned according to the centroid of the vertical projection of the functional cavities. The ventilation area is a cylindrical region enclosed by the inner ring functional cavities, forming a complete resonant cavity via a ring-shaped base plate. This material combines the resonant characteristics of a Helmholtz resonator, achieving mid-to-low frequency broadband sound insulation through multiple parallel HR combinations. The hollow tube design ensures ventilation, and the mid-to-low frequency band utilizes a non-local coupling sound absorption mechanism for sound insulation. A 4.6cm thick specimen can block 90% of incident wave energy (TL≥10dB) in the 435~1700Hz range, and customized designs can be achieved simply by adjusting the aperture. The improved design incorporates a connecting small hole in the center of the inner and outer functional cavity partitions to form a connected functional cavity, bridging the gap between resonance absorption peaks and enhancing low-frequency sound absorption. The improved unit can achieve the same sound insulation effect in the range of 385~1700Hz.

This application discloses a thermally broken aluminum alloy casement window, belonging to the field of doors and windows. It includes an outer frame, an inner frame installed inside the outer frame via a thermally broken strip, a side frame mounted on the inner wall of the inner frame via two hinges, a sash frame fixedly installed on one side of the side frame, and a glass assembly installed inside the sash frame. Both the inner frame and the sash frame are equipped with Helmholtz resonators. The sound insulation layer filled inside the sash frame effectively isolates external noise and reduces the impact of internal noise. At the same time, some sound energy can be absorbed by the outer tempered glass and the intermediate PVB film, while the air layer of the inner double-glazed glass can further block the transmission of sound waves. Furthermore, the Helmholtz resonator can be used to specifically absorb noise of a certain frequency.

The application provides a noise reduction adapter of an atomization mask, which comprises a first adapter part and a second adapter part connected with the first adapter part, the first adapter part is connected with an atomization cup, and the second adapter part is connected with the atomization mask; a first atomization flow channel is formed in the first adapter part, a branch protrusion is arranged on the first adapter part, the branch protrusion protrudes from the first atomization flow channel, a cavity is formed in the branch protrusion, the cavity of the branch protrusion comprises an open end and a blind hole end, and the open end is communicated with the first atomization flow channel. The structure design of the branch protrusion is adopted, a suitable protrusion cavity is obtained through calculation, the volume of the cavity meets the Helmholtz resonance noise reduction principle, and the noise generated by airflow is effectively reduced.

The utility model relates to earphone technical field especially, a kind of precision frequency attenuator and earphone for earphone, frequency attenuator includes support part, the inside of support part is equipped with cavity structure, cavity structure includes thick tube cavity and thin tube cavity, thick tube cavity is connected with thin tube cavity, one end of thick tube cavity extends to the upper surface of support part and forms a through-hole, through-hole is equipped with cavity cover. The utility model is based on Helmholtz resonator principle, form Helmholtz resonance cavity by specific earphone cavity structure design, utilize sound attenuation characteristic, determine attenuation range by cavity aperture and length, attenuate specific frequency by large Q value, narrow frequency band, influence range is small, the attenuation of volume is also far lower than traditional tuning net / paper scheme, the dynamic transient influence to sound is extremely small, and special attenuation tuning for non-resonant frequency can be realized, significantly improve the frequency response smoothness and hearing feeling natural degree of earphone, improve tone quality effect.

The utility model discloses a kind of heat preservation sound insulation wall structure based on microporous damping elastomer, it is related to wall body technical field, a kind of heat preservation sound insulation wall structure based on microporous damping elastomer, including concrete matrix, the one side of the concrete matrix is provided with microporous damping elastomer plate, for play heat preservation and sound insulation;The utility model is combined by the connecting column, vertical keel, interior trim, cross keel, honeycomb cavity plate, sound-absorbing cotton, vacuum insulation board, waterproof air-permeable membrane, microporous damping elastomer plate and bonding mortar of design, by the heat preservation structure of microporous damping elastomer plate and vacuum insulation board, the heat transfer coefficient of concrete matrix drops, microporous damping elastomer plate absorbs low-frequency noise using Helmholtz resonance principle, cooperate with the dissipation of medium-high frequency noise by honeycomb cavity plate and sound-absorbing cotton, so that wall air sound insulation amount is improved, significantly blocks traffic noise and indoor vibration.

A sound absorbing device functioning as a Helmholtz resonator comprises a cavity, a neck, and a movable structure arranged within the neck, wherein the movable structure is configured to adjust the resonance frequency of the Helmholtz resonator to achieve effective sound absorption.

This invention discloses a processing technology for noise-reducing Y-type tees, belonging to the field of Y-type tee processing technology, including the following steps: S1, composite tube blank preparation step: a three-layer composite tube blank is formed by co-extrusion process. The three-layer composite tube blank consists of a micro-perforated plate layer, a cavity layer, and a structural layer from the inside to the outside. The micro-perforated plate layer has multiple through-holes. The effect is that the co-extrusion process forms a three-layer composite tube blank consisting of a micro-perforated plate layer, a cavity layer, and a structural layer from the inside to the outside, and after integrated molding, the cavity layer forms a closed sound-absorbing cavity, thus constructing a "micro-perforated plate-resonant sound-absorbing cavity" composite noise reduction structure. This structure utilizes the Helmholtz resonance principle. When the low-to-medium frequency noise generated by the fluid flowing through the Y-type tee enters the micropores, the air generates viscous friction and sound energy consumption within the micropores, while resonance consumes sound energy within the cavity, achieving efficient absorption of fluid dynamic noise.

The utility model discloses an intake silencing system, power system and vehicle of vehicle relates to vehicle field. Intake silencing system includes: sensor, intake pipe, silencer, connecting pipe and is used for adjusting the adjusting mechanism of silencer, and sensor is used to gather the noise signal in the car, and silencer includes the resonant cavity casing, and the Helmholtz resonator is defined in the resonant cavity casing, and connecting pipe is connected between intake pipe and resonant cavity casing, and adjusting mechanism includes first adjusting assembly, and first adjusting assembly establishes on at least one of resonant cavity casing and connecting pipe, is used for adjusting the volume of resonant cavity casing, the length of connecting pipe, at least one of the pipe diameter of connecting pipe, and first adjusting assembly is electrically connected with sensor to control the action of first adjusting assembly according to the noise signal in the car. According to the utility model embodiment's intake silencing system has the self -adaptation regulation capacity, can eliminate the noise according to the noise information inside the vehicle.

This invention relates to a precipitation estimation device based on non-Newtonian fluids and a Helmholtz resonator, comprising a rain collector, a resonator, and a sound-receiving cavity connected sequentially from top to bottom, as well as a soundproof container encapsulating the resonator and the sound-receiving cavity. The rain collector is cylindrical, and the resonator is connected to the lower port of the rain collector. An acoustic conversion component is located at the top of the resonator, comprising two parallel, spaced horizontal thin films and a non-Newtonian fluid encapsulated between the two horizontal thin films. The sound-receiving cavity is connected to the bottom of the resonator, and its interior is used to house a microphone. This device utilizes the properties of non-Newtonian fluid dynamics to selectively transmit high-frequency raindrop signals while blocking low-frequency environmental noise, reducing noise at the source of data acquisition and avoiding the drawbacks of post-processing noise reduction in traditional algorithms.

The application discloses a kind of jet flow circulation control disc type aircraft, including disc type fuselage, multiple jet flow circulation control force vector generation units and control system.Each force vector generation unit includes oscillating acoustic generator, variable volume helmholtz resonator and Coanda curved surface, and force vector can be independently generated.Multiple units are distributed and arranged in disc type fuselage inside or surface, realize propulsion-lift integration.For different size aircraft, hierarchical control strategy is adopted: micro / small aircraft adopts attitude control mode, Coanda curved surface of force vector generation unit is directly used as upper surface wing, and aircraft attitude is changed by differential regulation jet flow momentum to realize translation;Large / manned aircraft adopts force vector control mode, and force vector generation unit is directly generated in multiple directions to generate thrust in each direction, keep fuselage horizontal, realize decoupling of translation and attitude.Aircraft can also adopt multi-level cascading nested layout, multi-layer stacked layout and outer cover protection and lift increasing device.The application provides a kind of disc type aircraft solution without exposed rotating parts, low noise, high safety, suitable for all-weather operation and adaptation to different size levels.

This application discloses a modular sound insulation panel, belonging to the field of architectural acoustics and noise control technology. It includes a metal outer frame, an internal sound-absorbing core layer, and a surface layer assembly on the front side of the metal outer frame. The sound-absorbing core layer comprises a gradient density foam layer and a Helmholtz resonator array plate, both sequentially installed inside the metal outer frame. The surface layer assembly includes a decorative perforated panel. Multiple sets of metal fasteners are provided on the front side of the metal outer frame, and multiple sets of magnetic fastening slots are opened on the back side of the decorative perforated panel. In use, the overall modular design allows users to freely combine panels with different sound-absorbing characteristics according to acoustic needs. The external surface layer assembly can be quickly disassembled and installed, and customization of the surface layer assembly ensures visual unity with the external home environment.

This invention provides an ultrasonic sensor with Helmholtz resonance enhancement integrated at the fiber end face, belonging to the field of fiber optic ultrasonic sensing technology. The ultrasonic sensor includes an optical fiber and a sensing structure integrated at the fiber end face. The sensing structure includes a hollow spherical cavity and a pipe communicating with the cavity. The outer wall of the hollow spherical cavity constitutes an optical whispering-gallery mode resonant cavity, and the hollow spherical cavity and the pipe together constitute an acoustic Helmholtz resonant cavity. The ultrasonic sensor achieves dual enhancement detection of ultrasonic signals through the synergistic effect of optical and acoustic resonance. This invention, employing the aforementioned ultrasonic sensor with Helmholtz resonance enhancement integrated at the fiber end face, solves the problems of existing ultrasonic sensors being susceptible to electromagnetic interference, having insufficient sensitivity, being difficult to manufacture, having low miniaturization, and being unable to simultaneously meet the requirements of anti-interference, miniaturization, and high-sensitivity weak ultrasonic detection.

This utility model belongs to the field of highway noise reduction technology and discloses a highway noise reduction device. The device includes a stainless steel supporting vertical wall installed on the outside of the highway guardrail. The top of the wall has a rainproof roof with a guide channel to prevent rainwater from affecting the internal structure. The side of the supporting vertical wall facing the road has a rigid PVC inner panel with sound-through holes, forming a resonance cavity inside. A Helmholtz resonance noise reduction component is installed at the bottom of the cavity, and the inner wall is lined with sound-absorbing foam made of egg-egg cotton. During operation, vehicle noise enters the resonance cavity through the sound-through holes in the inner panel. The Helmholtz resonance noise reduction component converts sound energy into mechanical vibration energy through a two-stage resonance system formed by the flat resonance cavity and the resonance rod. The sound-absorbing foam absorbs low-frequency noise and fills gaps to prevent sound wave reflection. The auxiliary structure ensures stable operation of the device, ultimately significantly reducing noise through a "conversion-dissipation" closed loop, minimizing the impact on surrounding residents.

This invention discloses a mid-to-low frequency hybrid broadband sound absorber, comprising: a first Helmholtz resonator with a first absorption peak frequency band; a second Helmholtz resonator with a second absorption peak frequency band; the second absorption peak frequency band being higher than the first absorption peak frequency band; and a plurality of discrete porous material blocks; the first and second Helmholtz resonators are spatially separated by at least one of the plurality of porous material blocks. This invention achieves effective extension of low-frequency sound absorption to mid-frequency; it achieves effective connection and fusion of optimized mid-to-high frequency sound absorption bands with extended low-to-mid frequency sound absorption bands; the sound absorber of this invention forms continuous, flat, and efficient broadband sound absorption performance within the target frequency band. Simulation verification shows that the average sound absorption coefficient in the 400Hz-2000Hz frequency band can exceed 0.8.

This invention provides a distributed air supply device and an air suspension system. The distributed air supply device includes a gas compression assembly, a connecting block, and a distribution valve assembly. The gas compression assembly includes a drive component and an air pump. The drive component is connected to the air pump to drive the air pump to compress gas. The air pump has an air outlet. The gas compression assembly is fixedly connected to one side of the connecting block. The connecting block has at least one air chamber, one end of which is connected to an air inlet or an air outlet. The distribution valve assembly is fixedly connected to the other side of the connecting block. The valve body of the distribution valve assembly has multiple air passages, which are connected to the other end of the air chamber. At least one air passage has an air supply port. The valve body integrates multiple control valves for controlling the opening and closing of the multiple air passages. The airflow enters the air chamber from the air outlet, or the airflow enters the air chamber from the multiple air passages. The air chamber constitutes a Helmholtz resonant cavity.

The application provides a combined stepped extension pipe sound absorption device, which comprises an aluminum honeycomb core material, the aluminum honeycomb core material comprises a plurality of honeycomb cells, and a stepped extension pipe is arranged in each honeycomb cell; each stepped extension pipe has different specifications; the two surfaces of the aluminum honeycomb core material are respectively sealed with a microporous plate and a rigid backing; one end of the stepped extension pipe has a gap with the rigid backing; the other end of the stepped extension pipe is tightly connected with micropores of the microporous plate, and the size of the hole at the end of the stepped extension pipe is the same as the size of the circular small hole of the microporous plate. The application utilizes the Helmholtz resonance principle and the heat loss and viscous loss in the sound transmission process, realizes low-frequency band sound absorption and wide-frequency sound absorption on the basis of ensuring the thickness of the device, and makes the device have good mechanical bearing performance while having sound absorption effect. The application has simple structure, very low cost and very wide engineering application value.