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111 results about "Sound power" patented technology

Sound power or acoustic power is the rate at which sound energy is emitted, reflected, transmitted or received, per unit time. It is defined as "through a surface, the product of the sound pressure, and the component of the particle velocity, at a point on the surface in the direction normal to the surface, integrated over that surface." The SI unit of sound power is the watt (W). It relates to the power of the sound force on a surface enclosing a sound source, in air. For a sound source, unlike sound pressure, sound power is neither room-dependent nor distance-dependent. Sound pressure is a property of the field at a point in space, while sound power is a property of a sound source, equal to the total power emitted by that source in all directions. Sound power passing through an area is sometimes called sound flux or acoustic flux through that area.

Method, device and equipment for reducing vibration noise of permanent magnet synchronous motor

The invention relates to the technical field of permanent magnet synchronous motors, in particular to a method, device and equipment for reducing vibration noise of a permanent magnet synchronous motor, and the method comprises the steps: building an electromagnetic field model, extracting radial electromagnetic force data, carrying out the spectrum and modal analysis, recognizing a main noise source, generating an acoustic power level waterfall plot through the combination of acoustic simulation, and defining an optimization target. The optimal scheme is finally obtained by designing the shape of a rotor hole, adjusting multi-parameter collaborative optimization of stator slot width and air gap length and the like, and iteratively optimizing key variables by adopting an intelligent algorithm. According to the method, the space 0-order quadruplicated frequency noise and 24-order octupled frequency noise are remarkably reduced, the torque fluctuation is inhibited, the output performance is ensured, the method is suitable for large-scale production, and the NVH quality of the motor is effectively improved.
Owner:HUAQIAO UNIVERSITY

Wave finite element and boundary element mixed composite board structure sound insulation performance prediction method

The invention provides a wave finite element and boundary element mixed composite board structure sound insulation performance prediction method, and the method belongs to the acoustics field, and comprises the steps: carrying out the post-processing of a wave finite element model based on the wave finite element model of a composite board structure and a corresponding equivalent nodal force, and obtaining the wave finite element equation of the whole composite board structure; based on a sound-structure coupling equation, through a boundary element method, a discrete boundary element equation related to the surface vibration speed of the composite board and the radiation sound wave pressure is constructed; coupling the wave finite element equation and the discrete boundary element equation of the whole composite board structure, and determining the sound pressure of radiation sound waves of the composite board structure and the surface vibration speed of the composite board; and based on the sound pressure of the radiation sound wave of the composite board structure and the surface vibration speed of the composite board, obtaining a sound insulation performance prediction result by calculating the sound power of the incident sound wave and the radiation sound wave, and completing prediction of the sound insulation performance of the composite board structure. The problems that the sound transmission loss of large plates and medium-high frequency plates is difficult to predict and the calculation cost is high are solved.
Owner:SOUTHWEST JIAOTONG UNIV

Woodworking machine tool noise sound power level measuring method based on sound intensity method

The invention discloses a woodworking machine tool noise sound power level measurement method based on a sound intensity method, and belongs to the technical field of machine tool noise measurement, and the method specifically comprises the steps: determining a housing surface covered by a tool rotation plane projection as a main sound radiation region, and determining a main bearing pedestal installation surface as an infrasound radiation region; sound pressure, vibration acceleration signals and dynamic air pressure signals of a main sound radiation area are collected; resampling a dynamic air pressure signal rotation angle domain, extracting a reference pneumatic pulsating waveform synchronous with tool tooth sweeping, and establishing an airflow induced sound pressure model according to the reference pneumatic pulsating waveform and a phase relation; calculating a surface normal vibration speed according to the vibration acceleration, and establishing a structure radiation sound pressure model in combination with a sound wave equation; decomposing the sound pressure signal to obtain two types of component estimation values, and performing parameter optimization to obtain net sound intensity of a main sound radiation area; extracting vibration frequency band energy of an infrasound radiation area, calculating equivalent sound intensity by combining a sound radiation efficiency model, and outputting a total sound power level by space integration; the invention provides an effective method for accurately measuring and controlling the noise of the woodworking machine tool.
Owner:FUJIAN PROV AGRI MACHANIZATION INST

Sound power adjusting system based on vehicle-mounted battery state self-adaption

The invention discloses a sound power adjusting system based on vehicle-mounted battery state self-adaption, and relates to the technical field of automobile electronic control, and the system comprises a vehicle state sensing and data collection module which is used for analyzing a bus message to obtain a power parameter and a load state, and collecting a battery physical parameter; the decision and strategy control module is connected to the sensing module and is used for calculating a sound equipment allowable output power threshold value under the current working condition and generating a control instruction according to the power priority mapping table and a battery state power calculation model; the execution and audio processing module is used for adjusting the carrier frequency and gain of a power amplifier according to the instruction and executing audio frequency band processing; and the cross-domain isolation power supply protection module is used for providing isolation power supply and switching to the emergency energy storage element when the voltage drops. Through a load preloading mechanism and dynamic internal resistance evaluation, adaptive matching of the sound power and the vehicle battery state is realized, and the system is effectively prevented from resetting due to voltage drop.
Owner:CHINA FAW CO LTD

A method and system for predicting cab noise

ActiveCN119601029BSustainable transportationSpeech analysisAcoustic transfer functionSound sources
The present invention provides a method and system for predicting cab noise, relating to the technical field of vehicle strength analysis. The method comprises: when a physical cab or a cab model is available, obtaining the vibration-acoustic transfer function from each cab mounting point to the driver's position through different methods, obtaining the mounting point load under different operating conditions, obtaining the sound-acoustic transfer function from the cab sound source to the driver's position through different methods, and performing sound power level testing on each cab sound source to obtain the sound source load of the cab sound source; combining the vibration-acoustic transfer function and the mounting point load to generate structure-borne sound; combining the sound-acoustic transfer function and the cab sound source load to generate airborne sound; and synthesizing the cab noise based on the structure-borne sound and airborne sound. The present invention can more quickly and accurately determine cab noise.
Owner:UNIV OF SCI & TECH BEIJING

Real-valued super-resolution direction-of-arrival estimation method for high-order acoustic field sensor array

The application relates to a real-valued super-resolution direction estimation method of a high-order acoustic field sensor array, which uses a received signal covariance matrix to approximately calculate an estimated value of noise power, avoids the iterative operation process of noise power in the prior art, improves the calculation efficiency, and reduces the floating-point operation amount. By constructing an augmented matrix, the array receiving data matrix and the array manifold matrix with a multi-dimensional structure of an element are made into Hermitian matrices, so that the unitary transformation processing of the related parameters of the high-order acoustic field sensor array is realized. On the basis of obtaining the array receiving data matrix and the array manifold matrix in the real number domain, the array receiving data matrix and the array manifold matrix are applied to a sparse approximate minimum variance method with a variable exponential factor, and the completely real-valued sparse approximate minimum variance direction estimation with a variable exponential factor is realized.
Owner:NORTHWESTERN POLYTECHNICAL UNIV

A noise simulation test method, device and electronic equipment of a vehicle

The application relates to a noise simulation test method and device of a vehicle and electronic equipment, relates to the technical field of vehicles, in particular to the technical field of simulation tests, and comprises the following steps: obtaining sound power level data of bench test of an electric drive system to be tested; constructing a noise simulation model of a target vehicle, determining an electric drive noise excitation source in the noise simulation model based on the sound power level data; performing noise simulation test based on the noise simulation model to obtain a noise simulation test result. The noise excitation source inside the electric drive shell is determined based on the bench test result, the actual excitation of the electric drive under different working conditions of the vehicle can be better reflected, and the accuracy of the noise simulation result is improved.
Owner:CHONGQING CHANGAN AUTOMOBILE CO LTD

Acoustic power modulation in a thermoacoustic machine

ActiveFR3130947B1Stirling type enginesCompression machinesSound sourcesPower modulation
The invention relates to a thermoacoustic machine (1) comprising a control device (14) configured to modulate the acoustic power generated by one or more acoustic sources (6-9) so that the temperature of an external source (2) connected to one or more thermoacoustic cells (10-13) of the machine (1) reaches or remains substantially the same as a setpoint temperature. Figure for the abstract: Fig. 1
Owner:EQUIUM GRP

Solar bluetooth sound power supply (k035)

ActiveCN309876238SSound powerTesting Methods
1. The name of the design product: solar Bluetooth sound power (K035). 2. The use of the design product: for energy storage, the product can also be used to play audio. 3. The design points of the design product: in shape. 4. The picture or photo that best indicates the design points: perspective view.
Owner:深圳市诚信诺科技有限公司

A method for generating an aluminum leakage determination model, an aluminum leakage detection method, and a device

The application relates to the technical field of aluminum processing supervision, in particular to a generation method of an aluminum leakage judgment model, an aluminum leakage detection method and equipment, which comprises the following steps: acquiring a first acoustic fingerprint signal and noise power spectral density under a casting state without aluminum leakage; acquiring a second acoustic fingerprint signal and environmental sound power spectral density under the casting state with aluminum leakage; calculating a noise suppression gain function; acquiring a training acoustic fingerprint signal and extracting casting acoustic fingerprint features based on the noise suppression gain function; classifying the casting acoustic fingerprint features to acquire non-aluminum leakage feature labels and aluminum leakage feature labels, and training to obtain an aluminum leakage judgment model; collecting real-time acoustic fingerprint signals under the casting state and obtaining real-time acoustic fingerprint features; inputting the real-time acoustic fingerprint features into the aluminum leakage judgment model and waiting for output judgment results; if the judgment results correspond to the aluminum leakage feature labels, it is determined that aluminum leakage is determined and alarm information is output. The application is used for improving aluminum leakage detection effects in a multi-noise environment.
Owner:JIANGSU ANSHENG INTELLIGENT TECHNOLOGY CO LTD

Loop free piston thermo-acoustic generator with built-in nuclear fuel

The invention relates to the technical field of power generation devices, and provides a nuclear fuel built-in loop free piston thermo-acoustic generator which comprises a thermo-acoustic engine, a control drum, a neutron reflecting layer and a piston type generator, the thermo-acoustic engine comprises a low-temperature heat exchanger, a heat regenerator and a reactor core which are arranged in sequence, and the reactor core is provided with a channel for working medium gas to circulate; the control drum is arranged on the peripheral side of the thermoacoustic engine; the thermoacoustic engine and the control drum are both arranged in the neutron reflecting layer, the piston type generator is provided with a main piston air cylinder, the main piston air cylinder is in acoustic communication with the outlet end of the thermoacoustic engine through an expansion cavity side resonance tube, and the piston type generator is used for converting part of acoustic power into electric energy and adjusting the acoustic impedance phase angle. The reactor core is directly used as a heat source to be arranged in the thermoacoustic engine, so that the reactor core directly replaces a hot end heat exchanger in the traditional technology, the arrangement of a middle heat transfer structure is avoided, the structure is simple, and the problem of low heat transfer efficiency caused by the heat transfer structure is avoided.
Owner:TECHNICAL INST OF PHYSICS & CHEMISTRY - CHINESE ACAD OF SCI

Road totally-enclosed sound barrier sound field prediction method and system

The invention relates to the technical field of environmental acoustics, discloses a road totally-enclosed sound barrier sound field prediction method and system, belongs to the field of environmental acoustics, and has very high practicability in sound field prediction and noise pollution evaluation of public road traffic noise after a totally-enclosed sound barrier is implemented. On the basis of the acoustic propagation principle, a new prediction method is provided for a road traffic noise source and a totally-closed sound barrier, a sound field is divided into two subsystems including a barrier internal space and an external space, and equivalent acoustic models of the two subsystems and a calculation method and recommendation parameters of the noise source sound power level are given respectively. According to the method, the sound environment of the high-rise building close to the urban road can be accurately predicted and calculated, and a basis is provided for noise pollution evaluation and control. And meanwhile, the method can be matched with a national standard method or commercial acoustic software for use, and has relatively high applicability.
Owner:CHINA SHIPPING ENVIRONMENT SCI & TECH (SHANGHAI) CO LTD

Vehicle abnormal sound identification method, system and device and computer readable storage medium

A vehicle abnormal sound identification method, system and device and a computer readable storage medium relate to the field of vehicle abnormal sound detection, and specifically comprise the following steps: determining a weighting coefficient corresponding to each 1 / 6 frequency band based on a weighting coefficient of a 1 / 3 frequency band corresponding to target vehicle noise data; obtaining a target noise characteristic curve and a non-target noise characteristic curve corresponding to each 1 / 6 frequency band; determining a second distance based on a first distance between a target upper limit curve of the target noise characteristic curve and the target noise characteristic curve, the first weighting coefficient and the second weighting coefficient; determining a first upper limit curve of the non-target noise characteristic curve based on the second distance and the non-target noise characteristic curve; and carrying out abnormal sound identification on the target vehicle based on the position relationship between the target noise characteristic curve and the target upper limit curve and the position relationship between the non-target noise characteristic curve and the first upper limit curve. The problem that abnormal sound with low sound power and / or narrow frequency band cannot be effectively identified in the prior art is solved.
Owner:DONGFENG MOTOR GRP

An acoustic mask for defining a square area sound power measurement and a method of making the same

The present application relates to the field of sound field measurement of medical ultrasonic diagnostic equipment, and particularly relates to a sound mask for limiting square area sound power measurement and a preparation method thereof. The sound mask comprises: a first absorbing layer, a reflecting layer, an intermediate layer and a second absorbing layer which are sequentially stacked from top to bottom; the reflecting layer is located at the central region of the first absorbing layer, the intermediate layer and the second absorbing layer, and a square sound transmission hole penetrating through the thickness of the reflecting layer is formed on the reflecting layer; the first absorbing layer, the reflecting layer, the intermediate layer and the second absorbing layer are tightly adhered through a pouring process to form an integral plate structure. The present application reasonably arranges the mask structure of the sound mask by establishing a theoretical model of sound wave vertical incidence multi-layer medium, so that the sound beam can be constrained, and the performance of the sound mask can strictly meet the technical requirements of the industry standard YY / T1084-2015.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA

Method and device for acoustically imaging fan noise, electric vehicle charging pile

The present disclosure relates to a method and device for acoustically imaging fan noise, an electric vehicle charging pile, and a storage medium. The method comprises: acquiring a noise time-domain signal generated by a fan when the fan is running; performing time-frequency conversion on the noise time-domain signal based on a short-time Fourier transform algorithm to obtain a noise frequency-domain signal; inputting the noise frequency-domain signal into a delay-and-sum beamformer to perform beamforming to obtain beam data; positioning principal component data of the beam data to obtain sound power data; and generating a sound image containing a sound source position according to the sound power data. In this embodiment, the resolution of the noise can be improved by positioning the principal component of the beam data, which achieves the effect of accurately positioning the sound source position and is conducive to obtaining a more accurate sound image.
Owner:XIAOMI EV TECH CO LTD +1

Woodworking machine noise sound power level measurement method based on sound intensity method

This invention discloses a method for measuring the sound power level of woodworking machine tool noise based on the sound intensity method, belonging to the field of machine tool noise measurement technology. Specifically, it includes: determining the housing surface covered by the projection of the tool's rotation plane as the main sound radiation area, and the main bearing seat mounting surface as the secondary sound radiation area; acquiring sound pressure, vibration acceleration signals, and dynamic air pressure signals in the main sound radiation area; resampling the dynamic air pressure signal in the rotational angular domain, extracting the reference air pulse waveform synchronized with the tool tooth sweep, and establishing an airflow-induced sound pressure model based on this and the phase relationship; calculating the surface normal vibration velocity based on the vibration acceleration, and establishing a structural radiation sound pressure model based on the sound wave equation; decomposing the sound pressure signal to obtain estimates of two types of components, and obtaining the net sound intensity of the main sound radiation area after parameter optimization; extracting the vibration frequency band energy of the secondary sound radiation area, calculating the equivalent sound intensity based on the sound radiation efficiency model, and spatially integrating to output the total sound power level. This invention provides an effective method for the accurate measurement and control of woodworking machine tool noise.
Owner:FUJIAN PROV AGRI MACHANIZATION INST

Exhaust plume control structure and power generating plant including same

An exhaust plume control structure includes a mounting member configured to mount to an exhaust flow source. A diverter member is coupled to the mounting member to radially direct an initial exhaust flow exiting from the exhaust flow source radially outward. A plurality of peripherally spaced, radially extending vanes are coupled to the mounting member and radially outward of the diverter member to separate the radially outward directed initial exhaust flow into a plurality of additional exhaust flows. Each vane has a radially diverging cross-section. Each of the plurality of additional exhaust flows has a same radial exit velocity. The structure reduces exhaust flow velocity and may provide back pressure to the initial exhaust flow. The structure has a sound power level of less than 115 dBA. A power generating plant including the structure is also disclosed.
Owner:GE INFRASTRUCTURE TECH LLC

Rocket takeoff jet noise prediction method and system containing multistage water spraying

The invention relates to a rocket takeoff jet flow noise prediction method and system containing multistage water spraying, and belongs to the technical field of aerospace transportation systems.The takeoff jet flow is dispersed into a series of independent point sound sources, sound power and sound radiation characteristics of the point sound sources are established respectively, meanwhile, a control volume is delimited in a jet flow water spraying area, and the control volume is calculated; the jet flow parameter ratio before and after water spraying is calculated, the sound power and radiation characteristics of the point sound source after water spraying are obtained through calculation, and then takeoff jet flow noise after water spraying is obtained; according to the method, takeoff jet noise prediction under different water spraying parameters can be realized, and reference is provided for noise environment design and water spraying scheme design; according to the rocket takeoff jet flow sound source distribution and the rocket takeoff water spraying position, the deflection jet flow noise radiation characteristic and the effective water spraying rate are obtained, the total sound pressure level precision at the takeoff noise peak moment is predicted to be superior to 3dB, the prediction precision of the peak frequency band of the 1 / 3 octave spectrum at the peak moment is predicted to be superior to 3dB, and the method has important engineering application and popularization value.
Owner:BEIJING INST OF ASTRONAUTICAL SYST ENG

A transformer load noise calculation method and system

The application discloses a transformer load noise calculation method and system, and the method comprises the following steps: S1, modal test is carried out on a transformer coil under inherent compression force of the transformer coil, and modal test parameters are obtained; S2, an equivalent model of the transformer coil is established, modal simulation is carried out on the equivalent model of the transformer coil, and modal simulation parameters are obtained; S3, the modal test parameters and the modal simulation parameters are compared, and equivalent material parameter values are determined; S4, a mapping relationship between the compression force and the equivalent material parameter values is established; S5, the electric power of the transformer coil is obtained by adopting three-dimensional magnetic field simulation; S6, the vibration amplitude of the transformer coil is calculated; S7, noise energy generated by the transformer coil is calculated; and S8, the sound power level of the transformer load is calculated. The mapping relationship between the compression force, material characteristics, vibration response and noise radiation is established, and more accurate load noise calculation is realized.
Owner:CHINA XD ELECTRIC CO LTD +2

A converter station sound insulation and noise reduction type enclosure structure design method based on artificial intelligence

This invention discloses an artificial intelligence-based design method for the sound insulation and noise reduction enclosure structure of converter stations, specifically relating to the field of converter station noise control. It addresses the problems of low-frequency control difficulties and noise leakage from ventilation openings leading to mismatch between the design scheme and station boundary targets in converter station enclosure structure design. The method involves obtaining equivalent continuous sound levels at representative points at the station boundary according to specifications and recording equipment operating status. These levels are then compared with existing predicted sound levels of the same diameter to obtain source term corrections, generating an equivalent sound power parameter set. Combining ventilation and heat dissipation constraints with the station's layout boundary calculation criteria, machine learning is used to comprehensively obtain the governance allocation coefficient. This guides the retrieval of the enclosure unit library to generate candidate enclosure combinations and matching opening noise reduction configurations. Finally, sound field and thermal ventilation checks are performed to output a constructable layout and node details, improving design feasibility and consistency.
Owner:STATE GRID HUBEI ELECTRIC POWER RES INST +1

Method and device for constructing underwater acoustic prediction model of steel ball

In order to solve the problem of low prediction precision in the existing underwater acoustic prediction model, the invention provides the method for constructing the underwater acoustic prediction model of the steel ball, firstly, a time domain signal of underwater entry of the steel ball is collected through a near-field virtual source method and a reverberation method, and through EMD denoising processing, the time domain signal of underwater entry of the steel ball is obtained; and respectively calculating sound power levels and drawing power spectrums, then carrying out filtering fusion to obtain the whole section of radiation sound power when the steel ball enters water, simultaneously extracting an initial impact sound power level, and obtaining bubble pulsation sound power through a difference value. And repeating the multi-working-condition experiment, drawing the change rule of the sound power level along with the particle size and the water falling height, further constructing a three-layer perceptron neural network model, performing training by combining a mean square error loss function, a Dropout strategy and 5-fold cross validation, and finally obtaining a model capable of accurately predicting the water entering acoustic characteristics of the steel ball. The method is suitable for hydroacoustics research and other technical fields.
Owner:HARBIN ENG UNIV

Plate shell structure reinforcement layout topological optimization method for sound radiation suppression

The invention discloses a plate shell structure reinforcement layout topological optimization method for sound radiation suppression, and belongs to the technical field of structural acoustics and intelligent optimization design. The method comprises the following steps: 1) establishing a base structure, defining a structure load, boundary conditions, optimization parameters and design variables, and determining the position of a seed point; 2) performing finite element analysis to obtain structural dynamic response; 3) acquiring a real unit set and an empty unit set, and calculating sensitivity; 4) dynamically updating the real unit width by adopting a global moving asymptote algorithm; 5) according to the width of the real unit, introducing a growth competition criterion to guide branches and degradation of the corresponding unit and update the material attribute of the unit to obtain a new reinforcement configuration; 6, whether the optimization process is converged or not is judged based on the target function value, and if not, finite element analysis is carried out again until the optimal reinforcement configuration is obtained.By means of the method, the radiation sound power of the plate shell structure can be effectively reduced, the acoustic performance is improved, the optimized configuration which is clear in boundary and easy to manufacture is obtained, the calculation efficiency is improved, and stability and convergence are guaranteed.
Owner:DALIAN UNIV OF TECH

Ultrasonic thrombolysis system capable of realizing real-time cavitation dose monitoring and self-adaptive acoustic beam regulation and control

The invention relates to an ultrasonic thrombolysis system capable of realizing real-time cavitation dose monitoring and self-adaptive acoustic beam regulation and control. The ultrasonic thrombolysis system comprises a thrombolysis main control unit which can configure a thrombolysis working state of a thrombolysis probe unit so as to perform in-vitro ultrasonic thrombolysis on a target area, and in the process of performing thrombolysis on a thrombus area by using a treatment sound beam, the thrombolysis main control unit configures the thrombolysis probe unit to receive a treatment echo signal and transmits the treatment echo signal to the thrombolysis probe unit. The current cavitation dose is monitored in real time based on the received treatment echo signal; and based on the monitored current cavitation dose, the thrombolysis main control unit at least adjusts the sound power of the treatment sound beam emitted by the thrombolysis probe unit until the current cavitation dose is matched with the target cavitation dose. According to the invention, the cavitation dosage during thrombolysis can be monitored in real time, the thrombolysis treatment acoustic beam can be subjected to self-adaptive acoustic beam regulation and control, and the reliability and thrombolysis efficiency of ultrasonic thrombolysis are improved.
Owner:VINNO TECH (SUZHOU) CO LTD

Magnetic screw driven thermoacoustic refrigeration system and method

The application relates to the technical field of low-temperature refrigeration, and provides a magnetic screw drive thermal-acoustic refrigeration system and method, which comprises at least one thermal-acoustic refrigeration basic unit, the unit comprising a pressure wave generating device, a thermal-acoustic refrigerator and a resonance tube. The pressure wave generating device comprises a pressure-resistant shell, a rotating motor, a magnetic screw shaft, a mover permanent magnet, a compression piston and a rotor permanent magnet arranged on the magnetic screw shaft; the magnetic screw shaft is connected with the rotating motor, the compression piston is arranged in the pressure-resistant shell, the mover permanent magnet is connected with the compression piston and is arranged in opposite interval with the rotor permanent magnet; a compression cavity is formed between the compression piston and the pressure-resistant shell; and the resonance tube is communicated with the compression cavity and the thermal-acoustic refrigerator. The rotating motor is used as a power source, the pressure wave generating device is used to replace a linear compressor, the manufacturing difficulty and cost are reduced, the rotating motor has high power density and high magnetic coupling efficiency, a large sound power can be output in a small volume, and the demand for high refrigeration capacity density is met.
Owner:TECHNICAL INST OF PHYSICS & CHEMISTRY - CHINESE ACAD OF SCI

Acoustic shield field sound insulation effect evaluation method based on oil tank vibration and sound signal inversion

The invention provides a sound insulation cover field sound insulation effect evaluation method based on oil tank vibration and sound signal inversion, and relates to the technical field of substation reactor sound insulation cover noise field evaluation. The method comprises the following steps: firstly, collecting surface vibration data of the extra-high voltage shunt reactor, and calculating an average sound pressure level of body noise according to the surface vibration data; constructing a multi-sound-source noise calculation model, and combining the frequency domain data of the full-band noise of the receiving point to solve the sound propagation attenuation under each frequency; a sound source single-band sound power inversion model is further established, and the sound power and the full-band sound power spectrum of the sound source are obtained; and finally, the insertion loss of the acoustic enclosure is calculated according to the full-band sound power spectrum and the average sound pressure level of the body noise, and accurate quantitative evaluation of the field sound insulation effect of the acoustic enclosure is realized. The method can effectively overcome the defects that traditional measurement is easily interfered by environmental noise and real insertion loss cannot be obtained.
Owner:NORTH CHINA ELECTRIC POWER UNIV

Evaluation method and device for knocking energy and radiation noise of speed-changing gear box

The invention relates to the technical field of engineering machinery, and discloses a method and device for evaluating knocking energy and radiation noise of a gearbox, and the method comprises the steps: collecting the radiation sound power of a reference gearbox under torque fluctuation at different moments; according to the obtained gear parameter set of the reference gearbox, the gear knocking energy of the reference gearbox is determined, the gear parameter set of the reference gearbox comprises the gear parameter of each gear in all gears of the reference gearbox, and the gear parameters comprise at least one of the gear radius, the gear rotating speed and the rotational inertia; according to the gear knocking energy of the reference gearbox and the radiation sound power of the reference gearbox, the gear knocking energy of the target gearbox and the radiation sound power of the target gearbox under torque fluctuation at different moments are predicted, and the target gearbox and the reference gearbox are the same gearbox. Therefore, the evaluation accuracy and the evaluation efficiency of the gear knocking level and the radiation noise of the gearbox can be improved.
Owner:GUANGXI LIUGONG MASCH CO LTD

Wireless Acoustic Power Receiver for a Load

This disclosure relates to wireless acoustic power reception. The disclosure includes a wireless acoustic power receiver comprising one or more acoustic transducers, and a corresponding method for operating the receiver. Each acoustic transducer is configured to: capture a first alternating current (AC) signal with receptively a first electrode and a second electrode; capture a second AC signal with receptively the first electrode at a first phase and the second electrode at a second phase, wherein the first AC signal and the second AC signal are respectively based on vibrations of a first vibration mode and a second vibration mode of a diaphragm that are respectively induced by a first acoustic frequency and a second acoustic frequency; and provide an electrical power of the first AC signal, the second AC signal at the first phase, and the second AC signal at the second phase to a load.
Owner:INTERUNIVERSITAIR MICRO ELECTRONICS CENT (IMEC VZW)

Fan broadband noise pipeline acoustic mode identification method

The invention provides a fan broadband noise pipeline acoustic mode identification method. The method comprises the following steps: determining all propagable pipeline acoustic modes of fan broadband noise on a sound source section under a specific frequency and an axial flow Mach number; establishing a modal transfer matrix of the broadband noise at a specific frequency; calculating an amplitude square ratio between all conduction modes and a reference sound mode of the broadband noise under a specific frequency under the condition of equal sound power; establishing a transfer relation between a cross-power spectrum matrix of a noise observation point of the measurement microphone array at a corresponding frequency and a cross-power spectrum matrix of a broadband acoustic mode amplitude at a sound source cross section; solving the square of the reference acoustic modal amplitude of the broadband noise under the specific frequency by using a least square method; and the squares of the amplitudes of all the propagable modes of the broadband noise under the specific frequency are solved. According to the method, a limited number of measurement microphones in the pipeline can be fully utilized, or the far-field microphones are directly utilized to realize analysis and identification of the broadband acoustic mode amplitude on the fan sound source cross section.
Owner:AECC COMML AIRCRAFT ENGINE CO LTD +1

Parameterization calculation method for vehicle-induced structural noise of waiting hall under elevated station bridge

The invention discloses an elevated station under-bridge waiting hall vehicle-induced structural noise parameterization calculation method, which is characterized by comprising the following steps: S1, dividing the top surface of an elevated station under-bridge waiting hall into areas, acquiring the area of each area, the coordinates of a central point and the time domain vibration acceleration of each central point, and further obtaining the vibration speed; s2, establishing a relationship between the vibration speed and the radiation sound power, and converting the vibration quantity into an acoustic quantity; s3, establishing a relationship between the radiation sound power of each region and the sound pressure radiated to the target point in each region; s4, superposing the sound pressure contributions of the full frequency band and all the areas to obtain total sound pressure; and S5, calculating the structural noise sound pressure level of the target point. Compared with a traditional finite element method and a boundary element method, the method has the advantages that the calculation complexity is remarkably reduced, the efficiency is greatly improved, the full-band calculation precision is improved, the data acquisition threshold is low, and the design period is shortened.
Owner:CHINA RAILWAY DESIGN GRP CO LTD +1