24 results about "Acoustic absorption" patented technology

An acoustic absorbing filler, the acoustic absorbing filler comprising agglomerates comprising a first phase comprising a plurality of porous particulates and a second phase comprising a binder; wherein the acoustic absorbing filler has a median sieved particle size of from 100 micrometer to 700 micrometers and a specific surface area of from 50 m2 / g to 900 m2 / g; wherein the acoustic absorbing filler has a normal incidence acoustic absorption of no less than 0.20 alpha at 400 Hz.

An acoustic absorption structure including a cellular structure which comprises tubular cells, closed at each of their ends by an acoustically resistive layer and a reflective layer, and at least one individual partitioning system, placed in a single cell and including a partition configured to separate the cell into first and second compartments, at least one opening passing through the partition, several feet independent of the conduit, having a first end connected to the partition and a second end in contact against the reflective layer, and at least one conduit which has a first end rigidly secured to the partition surrounding the opening and a second end spaced apart from the reflective layer.

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 discloses polyurethane foam with high sound absorption coefficient and a preparation method thereof, and relates to the technical field of polyurethane foam materials. The polyurethane foam is prepared by the reaction of component A and component B. The component A comprises the following raw materials in parts by weight: polyether polyol 45-55 parts, polymer polyol 35-40 parts, amine catalyst 0.01-0.03 parts, pentamethyl dipropylene triamine 0.5-2.0 parts, tin catalyst 0.01-0.03 parts, water 1-3 parts, pore opener 3-4 parts, and mixed silicon oil 1.2-1.6 parts. The component B is diphenyl methane diisocyanate, and the amount of the component B is 70-90 parts by weight. By introducing pentamethyl dipropylene triamine as a synergistic catalyst in a specific amount, the foam pore structure and the open porosity of the foam can be significantly optimized, and the prepared polyurethane foam has significantly improved sound absorption performance in the medium and low frequency range.

An acoustic absorption structure including at least one cellular structure between an acoustically resistive layer and a reflective layer. The cellular structure includes a first face in contact with the acoustically resistive layer, a second face in contact with the reflective layer, and a multitude of cells each discharging at the level of the first and second faces, each cell being delimited by at least one partition, wherein the cellular structure comprises at least one partitioning enclosure positioned in one of the cells of the cellular structure and connected to at least one partition delimiting the cell. The partitioning enclosure separates an interior zone inside the partitioning enclosure and an exterior zone situated in the cell and outside the partitioning enclosure. The partitioning enclosure includes at least one through-orifice configured so that the interior and exterior zones communicate.

The present disclosure provides a laser chamber, a gas laser device, and a method of manufacturing an electronic device. A laser chamber of one aspect of the present disclosure includes a container filled with a laser gas; a first electrode disposed in the container; a second electrode disposed in the container in an opposed state to the first electrode; and an acoustic absorption material disposed on at least one of an upstream side and a downstream side of the laser gas with respect to the first electrode, so that a propagation speed of a sound wave generated in a discharge space between the first electrode and the second electrode is reduced in a direction away from the discharge space.

The invention relates to a silent communication face mask (1) intended to be placed on the head of a user (5), comprising: a shell (2) configured to cover the mouth and nose of the user (5), said shell (2) having at least one exhalation vent (14), at least one microphone (3) carried by the shell (2) and arranged so as to capture and transmit the user's speech (5), an acoustic absorption device (4) extending within the shell (2), the mask (1) having at least one first movable element (20) configured to adopt an open configuration of the exhalation vent (14) under the effect of the pressure of air exhaled by the user (5) and to adopt a closed configuration of the exhalation vent (14) in the absence of exhaled air, thus rendering the user's speech (5) unintelligible. Figure for the abstract: Fig. 1

The application provides an acoustic absorption assembly applied to an extractor hood, the extractor hood comprising a hood body, comprising: a fixed support comprising a base fixedly connected and a plurality of spaced support cantilevers, the base being used for fixedly connecting with the hood body; a free end of the support cantilevers away from the base being provided with an anti-falling protrusion; an acoustic absorption piece being provided with a plurality of assembly through holes matched with the support cantilevers, the assembly through holes being provided in one-to-one correspondence with the support cantilevers; the free end of the support cantilevers being used for extending into the assembly through hole to abut against an end side of the acoustic absorption piece through the anti-falling protrusion, so as to support and hang the acoustic absorption piece through the support cantilevers and limit the movement of the acoustic absorption piece along the support cantilevers through the anti-falling protrusion; and a radial dimension of the anti-falling protrusion being determined based on stress and deformation analysis of preset parameters of the acoustic absorption piece. The acoustic absorption piece is hung and fixed in the hood body through the support cantilevers, has small space occupation, and has good acoustic absorption and noise reduction effect.

The present disclosure provides a combustion chamber and a method, device and equipment for determining parameters of an acoustic absorption structure in the combustion chamber, and relates to the technical field of aero-engines. The combustion chamber comprises a flame tube composed of a heat source mounting surface arranged in a radial direction, and a side wall surface arranged in an axial direction on a first side of the heat source mounting surface; and an acoustic absorption structure arranged on at least one of the heat source mounting surface and the side wall surface. The present disclosure can effectively suppress low-frequency mode combustion instability in the combustion chamber.

The invention relates to the technical field of NVH (Noise Vibration and Harshness) control of an electric drive system of a new energy automobile, and discloses an acoustic bag for the electric drive system of the new energy automobile, which is characterized by comprising a sound absorption layer and a composite sound insulation layer, the composite sound insulation layer is an EPM (Ethylene-Propylene-Metallic) rubber layer with two sides covered with PET (Polyethylene Terephthalate) non-woven fabrics, and the sound absorption layer is a foaming PU (Polyurethane) layer; the double-faced PET-coated non-woven fabric comprises a first PET non-woven fabric layer and a second PET non-woven fabric layer, the EPM rubber layer is coated with the first PET non-woven fabric layer, and the first PET non-woven fabric layer makes contact with the foaming PU layer and is used for improving the bonding strength of the EPM rubber layer and the foaming PU layer; and the second PET non-woven fabric layer covers the outer surface of the EPM rubber layer and is used for improving the surface scratch resistance and improving the supporting property of the acoustic bag after high-temperature aging. According to the acoustic bag, by improving the structural design and material combination, the defects of a traditional acoustic bag in the aspects of interface bonding strength, tensile formability and supporting performance after high-temperature aging are effectively overcome.

This invention relates to a method for measuring the acoustic absorption coefficient of the shallow seabed, comprising the following steps: measuring the seawater depth of the experimental sea area using an echo sounder; measuring the average sound energy density generated by rainfall using a hydrophone vertical array; measuring the rainfall intensity using a rain gauge; measuring the sound power radiated underwater by rainfall per unit area of ​​the sea surface; and calculating the acoustic absorption coefficient of the shallow seabed. The measurement method of this invention has a clear principle, and by measuring the underwater noise generated by rainfall, it can cleverly measure the acoustic absorption coefficient of the shallow seabed across the entire frequency band.

The invention discloses a GA-BPNN-based focus area tissue in-situ sound absorption energy inversion method and system. The method comprises the following steps: calculating a mechanical response displacement value of focus area tissue under the action of sound radiation force; converting into a k space-frequency domain product relationship by using a convolution theorem; and constructing a GA-BPNN model: optimizing an initial weight and a threshold value of a BP neural network by using a genetic algorithm, training to obtain the GA-BPNN model, predicting acoustic radiation force by using the GA-BPNN model, and then inverting acoustic absorption energy distribution of the focus area by using the k space-frequency domain product relationship through Fourier inverse transformation. The method aims at solving the problems that a current detection method for evaluating sound field measurement associated with sound absorption energy is difficult to meet in-situ sound absorption energy evaluation of FUS related equipment in a focus area, and FUS safety and curative effect are reduced. A large amount of complex programming work can be avoided, and a prediction model related to the acoustic radiation force can be established only through limited tests.

Acoustic absorption structure comprising compartmentalized cells combining several types of resonators. The invention relates to an acoustic absorption structure comprising a honeycomb structure (62), interposed between an acoustically resistive layer (64) and a reflective layer (66), which includes walls (68) delimiting cells (70) and, for at least one cell (70): at least one and at most three L-shaped partitions (72, 72'), impermeable and spaced apart, which delimit a straight compartment (70.1) and at least one L-shaped compartment (70.2, 70.3), in each L-shaped compartment (70.2, 70.3), an inclined acoustically resistive porous partition (80, 80') which has an openness ratio less than or equal to 15% and divides the L-shaped compartment (70.2, 70.3) into first and second zones (80.1, 80.2, 80.1', 80.2') forming two types of resonators. This arrangement increases the frequency range of the processed acoustic waves.The invention also relates to an aircraft comprising at least one such acoustic absorption structure. Figure 7.

The application relates to the field of ship equipment, in particular to a detachable ship ventilation and noise reduction device. The detachable ship ventilation and noise reduction device comprises a plurality of groups of noise reduction plates spliced together and a steel framework used for being mounted on a ship body, the noise reduction plates are fixedly mounted on the steel framework, a plurality of noise reduction plates are used for constituting a barrel-shaped structure for enclosing a noise source, the noise reduction plate comprises a sound insulation plate used for being fixed on the steel framework, the sound insulation plate is arranged with at least two layers, the multiple layers of sound insulation plates are arranged in parallel and are fixedly arranged, the sound insulation plate comprises an inner layer plate and an outer layer plate used for being fixedly attached to the steel framework, a through hole is arranged on the inner layer plate, an acoustic absorption plate is further arranged on the inner layer plate, the acoustic absorption plate is provided with a conical protrusion protruding from the surface of the acoustic absorption plate, and the acoustic absorption plate is made of porous acoustic absorption material. Further, the problem that the noise reduction device cannot be well arranged due to the conflict between the noise reduction device and the line of sight in the prior art is solved.

The invention relates to a vortex wave-airfoil interference noise prediction method and device and a storage medium. The method comprises the following steps: firstly, acquiring a Mach number, an observation angle and airfoil geometric characteristics of a vortex wave-airfoil interference scene under a target working condition; describing a flow conservation quantity based on a non-sticky two-dimensional compressible Euler equation set, configuring a sound absorption layer boundary condition for absorbing sound wave interference and suppressing boundary reflection at the periphery of a computational domain, and constructing a numerical calculation model; then, based on surface pressure distribution and far-field sound pressure time domain data, fitting is carried out to obtain scale law formulas of different Mach numbers at multiple observation point angles; and finally, on the basis of a scale law formula, far-field noise of each observation point of different Mach numbers is calculated, and complete numerical simulation does not need to be repeatedly executed on each working condition. Therefore, prediction precision and calculation efficiency can be improved, and multiple working conditions can be covered.

The invention relates to a muted communication mask (1) intended for placement on the head of a user (5), the muted communication mask (1) comprising:-a housing (2) configured for covering the mouth and nose of the user (5), the housing comprising at least one expiration portion (14); -at least one microphone (3) carried by the housing (2) and arranged so as to be able to capture words spoken by the user (5) and to transmit words spoken by the user (5); -acoustic absorption means (4) extending in the housing (2), the mask (1) comprising at least one first movable element (20) configured to assume a configuration for opening the expiratory portion (14) under the urging effect of the air exhaled by the user (5), and to assume a configuration for opening the expiratory portion (14) under the urging effect of the air exhaled by the user (5); and in the absence of exhaling air, a configuration for closing the exhaling section (14) is adopted, so that the words spoken by the user (5) are not understandable.

Embodiments of the present specification provide an acoustic device, comprising: a diaphragm; a housing for accommodating the diaphragm and forming a first acoustic cavity and a second acoustic cavity corresponding to front and back sides of the diaphragm respectively, wherein the diaphragm radiates sound to the first acoustic cavity and the second acoustic cavity respectively, and conducts sound out through a first acoustic hole coupled with the first acoustic cavity and a second acoustic hole coupled with the second acoustic cavity respectively; and an acoustic absorption structure coupled with the second acoustic cavity, for absorbing sound in a target frequency range transmitted to the second acoustic hole via the second acoustic cavity, wherein the target frequency range includes a resonance frequency of the second acoustic cavity.

The invention relates to an acoustic panel comprising at least one wall element having a thickness of between 0.7 and 4 cm and comprising at least one slot having a height H of between 0.5 and 2 cm, more particularly between 0.6 and 1.75 cm, more particularly between 0.6 and 1.5 cm, into which a series of objects is introduced, each having a width and a length greater than the width, as well as a concavity oriented downwards when the wall element is positioned in such a way that its thickness is horizontal, the panel having a weighted acoustic absorption capacity, measured according to standard ISO-11654: 1997, of between 0.65 and 0.75.

The utility model discloses a thermoplastic elastomer door and window edge sealing strip with a good sound insulation effect, and belongs to the field of door and window edge sealing strips, the thermoplastic elastomer door and window edge sealing strip comprises an edge sealing strip body, the edge sealing strip body is applied to a door frame, the edge sealing strip body comprises a connecting rib, and a sealing rubber strip is arranged at the top of the connecting rib; the bottom of the connecting rib is provided with an anti-falling strip, a sound absorption cavity is formed in the middle of the end face of the sealing rubber strip, a sound absorption strip is arranged in the sound absorption cavity, a plurality of honeycomb sound absorption grooves are formed in the sound absorption strip, gaps are formed between the honeycomb sound absorption grooves, and the gaps are filled with sound absorption cotton. When sound waves are transmitted and pass through the sealing rubber strip, the sound waves can be repeatedly reflected in the honeycomb sound absorption grooves and the sound absorption cotton to reduce the strength, then the sound insulation effect of the edge sealing strip is improved, and people can conveniently create a quiet indoor environment.

The application provides a surface acoustic wave temperature sensor and a cable joint temperature monitoring system, the device comprises a reflective grating, a piezoelectric substrate, an interdigital transducer and an acoustic absorption part, the reflective grating, the interdigital transducer and the acoustic absorption part are attached to the piezoelectric substrate, the interdigital transducer is composed of two groups of staggered comb-shaped metal strips, is used for directly exciting and passively detecting a surface acoustic wave on a piezoelectric substrate material, the material of the piezoelectric substrate is EVA-PZT-metal nanoparticles, the piezoelectric substrate is used for realizing mutual conversion between an electric signal and a surface acoustic wave signal, a first sub-grating structure and a second sub-grating structure of the reflective grating are respectively arranged on the two sides of the interdigital transducer, are used for reflecting and superimposing a sound signal to form resonance, and the acoustic absorption part is arranged outside the reflective grating. The surface acoustic wave temperature sensor made of a flexible material can be placed in the cable joint, and the problem that the distributed optical fiber temperature measurement in the prior art cannot realize accurate monitoring of the temperature in the cable joint is solved.

An acoustic absorption structure having a cellular structure, interposed between an acoustically resistive layer and a reflective layer, which has walls delimiting cells and, for at least one cell: at least one, and at most three, L-shaped partitions which are impermeable and spaced apart from one another and which delimit a straight compartment and at least one L-shaped compartment, in each L-shaped compartment an inclined acoustically resistive porous partition which has a perforation rate of less than or equal to 15% and divides the L-shaped compartment into first and second zones forming two types of resonators. Also an aircraft with at least one such acoustic absorption structure.

The utility model relates to the technical field of acoustic detection, in particular to an acoustic sound absorption performance detection sample piece with a spiral groove, which comprises a sealed shell with a resonant cavity, one surface of the shell protrudes inwards to form a convex block, and the convex block is provided with a spiral groove. A spiral groove is formed in the surface, provided with the protruding block, of the shell in the direction of the protruding block, and the spiral groove is communicated with the resonant cavity. The spiral groove is located in the protruding block of the detection sample piece, namely the neck of the resonator, the equivalent length is increased, the size is compressed, the spiral groove can achieve a long sound channel path in a very small physical space, equivalently, the equivalent neck length is increased, and a very long linear structure is not needed. Besides, low-frequency resonance can be realized while the small size can be kept through the structural arrangement, and the resonant frequency under a given volume can be made lower by taking the convex block with the spiral groove in the detection sample piece as the neck part.

The application provides an acoustic absorption structure, comprising at least one acoustic absorption unit. The acoustic absorption unit comprises a plurality of sub-units and a plurality of connecting portions. The sub-units are arranged in an array and are connected to each other by the connecting portions to collectively surround an acoustic transmission slot. Each of the sub-units comprises an acoustic absorption chamber. Each of the connecting portions comprises a connecting passage. The connecting passages of the connecting portions are respectively communicated with the acoustic absorption chambers of the sub-units. The connecting passage of at least one of the connecting portions is communicated with the acoustic transmission slot.