Enhancement of the sound power of a component of a complex noise source by sound from other nearby components

1988 ◽  
Vol 84 (1) ◽  
pp. 262-274 ◽  
Author(s):  
Robert Hickling ◽  
Samuel P. Marin
Keyword(s):  
Noise Source ◽  
Sound Power

Sound Power Assessment, Noise Source Identification and Directivity Analysis of Compaction Machines

2021 ◽  
Author(s):  
Milind Dadarao Kandalkar ◽  
Jaykumar bari ◽  
Dhondiram Mole ◽  
Nagesh Harishchandra Walke
Keyword(s):  
Source Identification ◽  
Noise Source ◽  
Sound Power ◽  
Noise Source Identification

Identification of the Vehicle Noise Source by Sound Intensity Method

2011 ◽  
Vol 346 ◽  
pp. 634-638 ◽  
Author(s):  
He Li ◽  
Qing Rong Zhao ◽  
Bang Chun Wen
Keyword(s):  
Power Spectrum ◽  
Noise Source ◽  
Sound Intensity ◽  
Regulation System ◽  
Sound Power ◽  
Analysis Software ◽  
Noise Sources ◽  
Vehicle Noise ◽  
Measurement Results ◽  
Radiation Noise

In this paper, we analysed the level of radiation noise and distribution of noise sources of car’s engine and front panels by using sound intensity method. To get the nephogram of sound intensity and sound power spectrum, we used the sound intensity probe and Multi-channel Data Acquisition Regulation System B&K 3560-D and Pulse Data Processing Analysis Software. By analysing experimental results, we can conclude the location of noise sources of these parts. The measurement results will serve as a reference for the car noise reduction.

Analysis of the Sound Power Level Emitted by Portable Electric Generators (Outdoor Powered Equipment) Depending on Location and Measuring Surface

2013 ◽  
Vol 430 ◽  
pp. 266-275 ◽  
Author(s):  
Elena Postelnicu ◽  
Valentin Vladut ◽  
Cristian Sorica ◽  
Petru Cardei ◽  
Ion Grigore
Keyword(s):  
Noise Source ◽  
Power Level ◽  
Acoustic Power ◽  
Sound Power ◽  
Noise Emission ◽  
Sound Power Level ◽  
Measuring Surface ◽  
Measurement Surface ◽  
Electric Generators

Acoustic power is a measure which must be specified on the outdoor used equipments and its determination depends on several factors: the place where the equipment works (indoor or outdoor), the placement of the microphones for its determination (the distance less or greater from the noise source), the shape of the measurement surface (parallelepiped or hemispherical). This paper aims to analyze the values obtained in these situations and interpret the data to determine the influence that each factor has on the acoustic power compared with the values obtained (permissible) according to Directive regarding noise emission D 2000/14/EC.

scholarly journals COGENERATION UNIT NOISE REDUCTION BY ITS CASE

2021 ◽  
Vol 2021 (2) ◽  
pp. 4501-4504
Author(s):  
RADEK STRAMBERSKY ◽  
◽  
VACLAV PAVELKA ◽  
TOMAS PAWLENKA ◽  
PAVEL SURANEK ◽  
...  
Keyword(s):  
Noise Reduction ◽  
Frequency Spectrum ◽  
Noise Source ◽  
Microphone Array ◽  
Noise Measurement ◽  
Sound Power ◽  
Final Number ◽  
Beamforming Algorithm

This paper deals with cogeneration unit noise measurement by the acoustic camera. Noise is not only measured as the final number of sound power levels, but also its original location is determined with the use of the beamforming algorithm. The properties of the used microphone array are considered and numerically calculated as every different microphone array layout will measure with another resolution. From the frequency spectrum, the possible technical source is determined. The results of noise source visualization show the cogeneration unit case noise decreasing effect while also offering the possibilities for design improvements.

A Simulation on Aerodynamic Noise of an Air-Conditioning Duck

2012 ◽  
Vol 466-467 ◽  
pp. 778-783
Author(s):  
Wen Ku Shi ◽  
Jian Peng Yao ◽  
Suo Jun Hou ◽  
Fu Xiang Guo ◽  
De Guang Fang
Keyword(s):  
Flow Field ◽  
Air Conditioning ◽  
Transient Flow ◽  
Noise Source ◽  
New Products ◽  
Flow Simulation ◽  
Broadband Noise ◽  
Aerodynamic Noise ◽  
Sound Power ◽  
Simulation Results

The transient flow field is needed in order to predict the aerodynamic noise of an automotive HVAC duck by conventional methods. However, it is time-consuming when are several improved schemes .To solve the problem, schemes with large sound power can be discarded using Broadband Noise Source (BNS) model at first. Then, the best scheme can be found after the transient flow simulation .In this paper, an automotive HVAC duck is used as an example. Firstly BNS is used to predict which scheme is noisier, secondly the aerodynamic noise is computed using Fluent coupled with Sysnoise. At last they come to the same conclusion. The simulation results indicate BNS model can be used to find which scheme is the best without computing the transient flow field. So it can shorten the cycle of developing new products.

scholarly journals A Tandem Axial-Piston Unit Based Strategy for the Reduction of Noise Sources in Hydraulic Systems

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5377
Author(s):  
Leandro Danes ◽  
Andrea Vacca
Keyword(s):  
Transfer Functions ◽  
Noise Source ◽  
Destructive Interference ◽  
Sound Power ◽  
Vibration Band ◽  
Hydraulic Systems ◽  
Source Reduction ◽  
Third Harmonic ◽  
Pressure Ripple ◽  
Axial Piston

This article presents a novel passive fluid borne noise source reduction strategy, based on tandem axial-piston unit indexing with the usage of symmetric lines. The strategy consists of setting the phase between the two synchronous units to accomplish destructive interference in targeted unit harmonics. A strategy capable of achieving destructive interference in all odd harmonics is investigated first analytically and then confirmed by a simulation study. Experiments on the proposed strategy confirmed its effectiveness at the first and third pump fundamental harmonics, and pressure ripple reduction was accomplished. The fluid borne noise source reduction in the first and third harmonic is verified to be propagated to pipe vibration and sound power. Regarding the first harmonic, pressure ripple was reduced by up to 18 dB; while for third harmonic, pressure ripple was reduced by up to 11 dB. In the experiment, however, noise cancellation is not achieved for the higher odd harmonics, as is instead found in the simulation. Conversely, transfer functions form pressure ripple to pipe wall acceleration are obtained experimentally, and a critical vibration band from 2000 Hz to 3000 Hz is identified as being crucial for effective overall sound power reduction.

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