Aircraft and Airport Transportation Noise Sources and Control

2020 ◽  
pp. 661-676
Keyword(s):  
Noise Sources ◽  
Transportation Noise ◽  
And Control

scholarly journals Noise Source Identification of a Ring-Plate Cycloid Reducer Based on Coherence Analysis

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Bing Yang ◽  
Yan Liu
Keyword(s):  
High Performance ◽  
High Reliability ◽  
Coherence Analysis ◽  
Noise Sources ◽  
Ring Plate ◽  
Speed Reducer ◽  
Noise Test ◽  
Analysis System ◽  
And Control ◽  
Plate Type

A ring-plate-type cycloid speed reducer is one of the most important reducers owing to its low volume, compactness, smooth and high performance, and high reliability. The vibration and noise tests of the reducer prototype are completed using the HEAD acoustics multichannel noise test and analysis system. The characteristics of the vibration and noise are obtained based on coherence analysis and the noise sources are identified. The conclusions provide the bases for further noise research and control of the ring-plate-type cycloid reducer.

scholarly journals Noise Sources and Control, and Exposure Groups in Chemical Manufacturing Plants

2019 ◽  
Vol 9 (17) ◽  
pp. 3523
Author(s):  
Rikhotso ◽  
Harmse ◽  
Engelbrecht
Keyword(s):  
Manufacturing Sector ◽  
Grey Literature ◽  
The United States ◽  
Raw Material ◽  
Mechanical Equipment ◽  
Exposure Level ◽  
Noise Sources ◽  
Manufacturing Plants ◽  
Chemical Manufacturing ◽  
And Control

The chemical manufacturing industry employs sophisticated mechanical equipment to process feedstock such as natural gas by transforming it to usable raw material in downstream sectors. Workers employed at these facilities are exposed to inherent occupational health hazards, including occupational noise. An online and grey literature search on ScienceDirect, Oxford Journals online, PubMed, Medline, Jstor and regulatory bodies using specific keywords on noise emission sources in the manufacturing sector was conducted. This review focuses on noise sources and their control in chemical manufacturing plants along with the receptors of the emitted noise, providing hearing conservation programme stakeholders valuable information for better programme management. Literature confirms that chemical manufacturing plants operate noise emitting equipment which exposes job categories such as machine operators, process operators and maintenance personnel amongst others. Prominent noise sources in chemicals manufacturing industries include compressors, pumps, motors, fans, turbines, vents, steam leaks and control valves. Specific industries within the chemical manufacturing sector emit noise levels ranging between 85–115 dBA (A-weighted sound pressure level), which exceed the noise rating limit of 85 dBA used in South Africa and United Kingdom, as well as the 90 dBA permissible exposure level used in the United States, levels above which workplace control is required. Engineering noise control solutions for plant equipment and machinery operated in chemical manufacturing plants are available on the market for implementation.

scholarly journals Aeroacoustics of Turbulent Jets: Flow Structure, Noise Sources, and Control

2006 ◽  
Vol 49 (4) ◽  
pp. 1078-1085 ◽  
Author(s):  
Ephraim Jeff GUTMARK ◽  
Bryan William CALLENDER ◽  
Steve MARTENS
Keyword(s):  
Flow Structure ◽  
Turbulent Jets ◽  
Noise Sources ◽  
And Control

A Study on Noise Test and Control of Combine Harvester

2014 ◽  
Vol 971-973 ◽  
pp. 324-328
Author(s):  
Yao Ming Li ◽  
Pan Sun
Keyword(s):  
Present Situation ◽  
National Standard ◽  
Sound Insulation ◽  
Noise Sources ◽  
Combine Harvester ◽  
Noise Test ◽  
Insulation Plate ◽  
Combine Harvesters ◽  
Standard Limit ◽  
And Control

Faced at the present situation that the noise level of most combine harvesters was generally higher than the national standard limit in our country, experiments carried out to reduce the driver's ear noise, which chosen 4LZ-5.0E type tracked combine harvester as experimental prototype. The method of noise sources separation was used to test the whole machine on different working conditions. Based on the contribution analysis to obtain the contribution of main working parts for the driver's ear noise and identify the main noise sources. Through designing the reasonable structure of sound insulation for engine and installing the sound insulation plate on the left of driver, testing results showed that the noise of the driver's ear was reduced 3.1dB (A).

Auralizing the impact of transportation noise sources

2020 ◽  
Vol 148 (4) ◽  
pp. 2568-2568
Author(s):  
Kelsey Rogers ◽  
Benjamin E. Markham
Keyword(s):  
Noise Sources ◽  
Transportation Noise ◽  
The Impact

Insertion loss (IL) of finite sound barriers of different contours - An introduction to geometrical solutions in 3-D space

2021 ◽  
Vol 263 (6) ◽  
pp. 164-174
Author(s):  
Giora Rosenhouse
Keyword(s):  
Insertion Loss ◽  
Vector Analysis ◽  
Control Points ◽  
Noise Sources ◽  
3D Space ◽  
Sound Barriers ◽  
Environmental Acoustics ◽  
And Control ◽  
Rectangular Barrier

The design of finite sound barriers noise sources and control points requires calculations beyond those that are used when the Maekawa formula is applied, since the problem involves polygon sd barriers located in various possible orientations in 3D space. We present here some means that are linked to basic mathematical geometrical tools. Those means are relatively simple, as compared to the physical formulation of the relevant diffraction solutions for sound barriers (e.g. Rosenhouse, 2019, 2020). Such calculations can apply algebraic, trigonometric or vector analysis and their combinations to define the geometries of barrier IL. This approach includes the location of the sources and control points, which are essential as data for finding IL and other issues of environmental acoustics. We will show solutions including results of IL for a common rectangular barrier, as compared to IL of a barrier with a sloped top and side, among other possibilities.

scholarly journals A Time-Frequency Based Approach for Acoustic Emission Assessment of Sliding Wear

Lubricants ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 52
Author(s):  
Igor Rastegaev ◽  
Dmitry Merson ◽  
Inna Rastegaeva ◽  
Alexei Vinogradov
Keyword(s):  
Acoustic Emission ◽  
Sliding Friction ◽  
Monitoring And Control ◽  
Destructive Testing ◽  
Noise Sources ◽  
Processing Technologies ◽  
Time Frequency ◽  
On Line ◽  
Ae Signal ◽  
And Control

The acoustic emission method is one of few contemporary non-destructive testing techniques enabling continuous on-line health monitoring and control of tribological systems. However, the existence of multiple “pseudo”-acoustic emission (AE) and noise sources during friction, and their random occurrence poses serious challenges for researchers and practitioners when extracting “useful” information from the upcoming AE signal. These challenges and numerous uncertainties in signal classification prevent the unequivocal interpretation of results and hinder wider uptake of the AE technique despite its apparent advantages. Currently, the signal recording and processing technologies are booming, and new applications are born on this support. Specific tribology applications, therefore, call for developing new and tuning existing approaches to the online AE monitoring and analysis. In the present work, we critically analyze, compare and summarize the results of the application of several filtering techniques and AE signal classifiers in model tribological sliding friction systems allowing for the simulation of predominant wear mechanisms. Several effective schemes of AE data processing were identified through extensive comparative studies. Guidelines were provided for practical application, including the online monitoring and control of the systems with friction, characterizing the severity and timing of damage, on-line evaluation of wear as sliding contact tests and instrumented acceleration of tribological testing and cost reduction.

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