The Impact of Traffic Parameter Assessment on Noise Emission

2016 ◽  
pp. 161-170
Author(s):  
Justyna Sordyl
Keyword(s):  
Noise Emission ◽  
The Impact

scholarly journals DEUFRABASE: A Simple Tool for the Evaluation of the Noise Impact of Pavements in Typical Road Geometries

Environments ◽  
2019 ◽  
Vol 6 (3) ◽  
pp. 27 ◽  
Author(s):  
Michel Bérengier ◽  
Judicaël Picaut ◽  
Bettina Pahl ◽  
Denis Duhamel ◽  
Benoit Gauvreau ◽  
...  
Keyword(s):  
Traffic Noise ◽  
Emission Spectra ◽  
Low Noise ◽  
Noise Emission ◽  
Simple Method ◽  
Acceptable Error ◽  
The Road ◽  
Noise Impact ◽  
On The Road ◽  
The Impact

Traffic noise is considered by people as one of the most important sources of environmental discomfort. A way to limit the traffic noise is to reduce the noise emission, for example, by using specific low noise pavements, particularly in suburban areas. However, in real situations, it can be difficult to evaluate the impact of a given pavement, because it depends, for example, on the road geometry, the meteorological conditions, or the distance of the receiver position. Finally it can be difficult to select the most appropriate pavement for a given noise reduction objective. In this paper, a simple method is proposed to evaluate the noise impact of a pavement, in typical road geometries and environmental conditions. The proposed approach uses two databases, the first one based on measurements of emission spectra of road vehicles on several typical pavements, the second one made of pre-calculations of noise propagation for typical road configurations. Finally, the method is implemented in an interactive web tool, called DEUFRABASE, which allows one to obtain a fast estimation of the L Aeq (1 h or 24 h) and L den noise levels for various pavements and road configurations, as functions of the traffic flow and composition. By comparing the method with measurements, it is showed that the tool, although based on a restricted number of pavements and on several simplifications, can predict the noise impact of typical road configurations, with an acceptable error, most often less than 2 dB.

Effects of the reduction of aircraft noise emission due to the travel restriction during the COVID-19 pandemic at residential areas around Tan Son Nhat Airport

2021 ◽  
Vol 263 (1) ◽  
pp. 5114-5124
Author(s):  
Thulan Nguyen ◽  
Tran Thi Hong Nhung Nguyen ◽  
Bach Lien Trieu ◽  
Makoto Morinaga ◽  
Yasuhiro Hiraguri ◽  
...  
Keyword(s):  
Aircraft Noise ◽  
Residential Areas ◽  
Noise Levels ◽  
Noise Emission ◽  
Acoustic Environment ◽  
Comparison Results ◽  
Travel Restrictions ◽  
Before And After ◽  
The Impact ◽  
Travel Restriction

The travel restrictions caused by the epidemic outbreak in early 2020 worldwide have caused many changes in all aspects of life, especially in the acoustic environment. This study examines the impact of this environmental change at Tan Son Nhat International Airport (TSN), the largest airport in Vietnam, by comparing the situations before and after the airport stopped operating all international flights in March 2020. The after-the-change survey was conducted in 2 phases, June and September 2020, three months and six months after the stop decision. The number of flights observed in August 2019 was 728; this number is 413 and 299 for the two surveys in 2020. The range of noise levels estimated for 12 sites around TSN decreased from 63-81 dB in 2019 to 32-67 dB in June 2020 and 33-69 dB in September 2020. At the same aircraft noise level, the percentage of highly annoyed (% HA) and the percentage of insomnia (%ISM) in the 2020 survey are higher than those in the 2019 survey. The comparison results of reaction to noise before and after the TSN's noise change indicated an increase in negative responses to noise might happen in the increased noise and reduced noise situation.

A Robust Industrial Procedure for Measuring Modal Sound Fields in the Development of Radial Compressor Stages

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Peter Limacher ◽  
Carsten Spinder ◽  
Marius C. Banica ◽  
Heinz-Jürgen Feld
Keyword(s):  
Measurement System ◽  
Noise Source ◽  
Sound Field ◽  
Temperature Stability ◽  
Noise Emission ◽  
Radial Compressor ◽  
Sound Fields ◽  
Compressor Inlet ◽  
Time Required ◽  
The Impact

The turbocharger is a significant noise source in large diesel engines, such as those used in container vessels. Its main noise source is the radial compressor, where improvements in silencers and turbocharger insulation have led to a considerable reduction of compressor inlet noise emission over the past few years. As a result, compressor outlet noise is now becoming increasingly significant for large engines. Recently, an in-house compressor testbed was upgraded by adding an acoustic modal measurement system (MSMS) that allows detailed investigation of modal sound fields inside the piping. This forms part of an updated compressor acoustic qualification procedure. This paper is an in-depth treatise of the characteristics of this modal measurement system. The calculation approach for the modal decomposition and a simplified alternative that assumes axial propagation, as well as relevant considerations, such as spatial resolution, averaging, and the use of multiple reference sensors, are addressed. Various measurement parameters, such as repeatability, measurement time, required temperature stability, pressure scaling, flow noise and their impact on measurement uncertainty were investigated. A successful validation of the modal sound measurement system with a well-known modal sound field at the compressor inlet is also presented. Finally, the characteristics of the modal sound fields of the compressor outlet of a typical modern turbocharger are discussed. Modal decompositions at the first two blade passing frequencies (BPFs) are presented for selected operating points (OPs). The response of total sound power levels (PWLs) to compressor speed along the operating line (OL) is examined by means of both the present and the simplified algorithm. A sensitivity analysis shows the impact of volume flow and rotational speed on the modal sound distribution.

Prediction of Sintered Fibrous Metal Liner Influence on Muffler Sound Attenuation Performance and Noise Emission for Single-Cylinder Motorcycle Engine Exhaust

2008 ◽  
Author(s):  
Mark C. Storm
Keyword(s):  
Gas Flow ◽  
Measurement Data ◽  
Sound Attenuation ◽  
Noise Emission ◽  
Engine Exhaust ◽  
Single Cylinder ◽  
Fibrous Metal ◽  
Metal Liner ◽  
Prediction Techniques ◽  
The Impact

This study contrasts two modeling techniques proposed to accurately predict the influence of sintered fibrous metal (a non-woven structure of metallic fibers attached to one another by sintering processes), as a liner substitute, on sound attenuation performance and resulting noise emission for conventional aftermarket dissipative mufflers. Predicted values are compared to sound measurement data from stationary engine exhaust tests of a commercially available single-cylinder 450cc off-road motorcycle. The performance prediction techniques rely on the appropriate application and combination of pre-existing silencer design, engine exhaust and gas flow performance models as an economic alternative to more complex and expensive modeling programs that are typically beyond the reach of most small to medium-sized businesses in the motorcycle aftermarket industry. With respect to test results that showed approximate acoustical parity between mufflers containing the two different liner types, application limitations on the most suitable prediction technique are presented along with suggestions for further model refinement or additional physical testing. Further research is also invited to explore the impact of this liner substitution on muffler backpressure and its consequential impact on realized engine power.

scholarly journals Assessment of Traffic Noise Pollution Due to Urban Residential Road Transport

2019 ◽  
Vol 8 (1) ◽  
pp. 34-52
Author(s):  
Elena Lezhneva ◽  
Katerina Vakulenko ◽  
Andrii Galkin
Keyword(s):  
Noise Exposure ◽  
Traffic Noise ◽  
Experimental Studies ◽  
National Income ◽  
Noise Pollution ◽  
Road Transport ◽  
Environmental Safety ◽  
Residential Areas ◽  
Noise Emission ◽  
The Impact

Abstract The problem of combating urban noise is closely linked to the rational transformation of the urban environment, which must go through the elimination or reduction of the number of sources of noise, the localization of the noise emission zone, reducing the level of sound sources and protection against noise for the residential areas. Theoretical and experimental studies of acoustic loading on the territory along the highway for the typical section of the urban territory have been conducted. To estimate the complex noise impact from all sources and from individual sources, as well as to predict the total noise exposure for this site, a noise map was constructed using software. As a measure to combat traffic noise in the territory along the highway, the location of the noise protection screen was justified, taking into account the loss of part of the national income as a result of the continuous impact of noise on a person.The results of the research allow to assess the degree of technogenic impact of noise pollution during the operation of the highway, which allows regulating, by administrative and legislative methods, the nature of the impact on natural objects and human health of certain types of activities, as well as reasonably proposing measures that ensure environmental safety when organizing urban streets traffic.

scholarly journals Performance of a small-scale construction and demolition waste recycling unit: a case study in northeastern Brazil

2021 ◽  
Vol 16 (4) ◽  
Author(s):  
Laís Carlos Boaventura Santos ◽  
Thaís Andrade de Sampaio Lopes ◽  
Luciano Matos Queiroz ◽  
Viviana Maria Zanta
Keyword(s):  
Production Capacity ◽  
Construction And Demolition Waste ◽  
Northeastern Brazil ◽  
Recycled Aggregate ◽  
Structural Function ◽  
Small Scale ◽  
Noise Emission ◽  
Demolition Waste ◽  
Natural Sand ◽  
The Impact

Environmental and operational performance of a full-scale small and decentralized construction and demolition waste (C&DW) recycling unit (SDRU) were evaluated. The SDRU was defined as having a production capacity of up to 5 m3 per hour, occupying up to 100 m2. The operational and environmental performance indicators of the SDRU were obtained from the literature and validated by expert judgment. Subsequently, the values of these indicators were obtained from a real-scale SDRU in Bahia state, Brazil. The results showed that the SDRU presented lower levels of noise emission, very small water and energy consumption, and inhalable-particle concentration values lower than the requirements of Brazilian environmental legislation. It was observed that 90% of the C&DW in the storage area had recycling potential. The characteristics of the fine recycled aggregate make it suitable for use in road or sidewalk paving, and the coarse recycled aggregate is suitable for use in concrete without structural function. A Life Cycle Assessment (LCA) of the SDRU was also applied and it was concluded that the use of the recycled aggregate for manufacturing concrete without structural function reduced the environmental impact in all the categories considered, compared with the impact of natural sand and gravel extraction from nature. It was possible to conclude that the implementation of the SRDU in developing countries can provide an effective step towards reducing environmental impacts from the construction sector.

scholarly journals Influence of Cutting Attachment on Noise Level Emitted by Brush Cutter during Tending of Young Forests

2019 ◽  
Vol 41 (1) ◽  
pp. 129-135
Author(s):  
Bartłomiej Naskrent ◽  
Witold Grzywiński ◽  
Adrian Łukowski ◽  
Krzysztof Polowy
Keyword(s):  
Significant Influence ◽  
Noise Level ◽  
Vegetation Type ◽  
Body Position ◽  
Pine Plantations ◽  
Noise Emission ◽  
Wire Cutting ◽  
Pine Stands ◽  
Young Forests ◽  
The Impact

A brush cutter is the most frequently used equipment for tending young forests. When cutting unwanted vegetation, the operator is exposed to various harmful factors, such as: a forced body position, noise, vibrations and exhaust emissions. In this study, the impact of cutting attachment type on the noise level during tending of young pine stands was examined. The attachments used during the tests included: a wire head and cutting blades with 2, 3 and 24 cutting teeth. The research was carried out on 2–3 year old Scots pine plantations covered with three types of vegetation: herbaceous, mixed and woody. It was proven that the the wire head was the device that generated the highest level of noise. In the case of cutting blades, the number of cutting teeth was the important factor. The greater the number of teeth in the cutting blades, the lower the noise level the device produced. There was no significant influence of vegetation type on noise emission level. Based on the results, in order to minimize operators’ exposure to noise, the use of wire cutting attachment should be limited.

scholarly journals Acoustic characteristics of a ported shroud turbocompressor operating at design conditions

2018 ◽  
Vol 21 (8) ◽  
pp. 1454-1468 ◽  
Author(s):  
Sidharath Sharma ◽  
Alberto Broatch ◽  
Jorge García-Tíscar ◽  
John M Allport ◽  
Ambrose K Nickson
Keyword(s):  
Decomposition Methods ◽  
Broadband Noise ◽  
Stable Operation ◽  
Noise Generation ◽  
Noise Emission ◽  
Spectral Signatures ◽  
Surge Margin ◽  
Flow Enhancement ◽  
Ported Shroud ◽  
The Impact

In this article, the acoustic characterisation of a turbocharger compressor with ported shroud design is carried out through the numerical simulation of the system operating under design conditions of maximum isentropic efficiency. While ported shroud compressors have been proposed as a way to control the flow near unstable conditions in order to obtain a more stable operation and enhance deep surge margin, it is often assumed that the behaviour under stable design conditions is characterised by a smooth, non-detached flow that matches an equivalent standard compressor. Furthermore, research is scarce regarding the acoustic effects of the ported shroud addition, especially under the design conditions. To analyse the flow field evolution and its relation with the noise generation, spectral signatures using statistical and scale-resolving turbulence modelling methods are obtained after successfully validating the performance and acoustic predictions of the numerical model with experimental measurements. Propagation of the frequency content through the ducts has been estimated with the aid of pressure decomposition methods to enhance the content coming from the compressor. Expected acoustic phenomena such as ‘buzz-saw’ tones, blade passing peaks and broadband noise are correctly identified in the modelled spectrum. Analysis of the flow behaviour in the ported shroud shows rotating structures through the slot that may impact the acoustic and vibration response. Further inspection of the pressure field through modal decomposition confirms the influence of the ported shroud cavity in noise generation and propagation, especially at lower frequencies, suggesting that further research should be carried out on the impact these flow enhancement solutions have on the noise emission of the turbocharger.

Computerized Noise Emission Simulation for a Multiunit Gas Compressor Station

2001 ◽  
Author(s):  
Roderich Resch ◽  
Luwig Pointner
Keyword(s):  
Computer Program ◽  
Noise Reduction ◽  
Case History ◽  
Gas Turbines ◽  
Compressor Station ◽  
Compressor Plant ◽  
Noise Emission ◽  
Noise Impact ◽  
The Impact

This paper describes a computer program simulation of the impact of noise emissions of Austrian’s largest gas compressor plant. The case history covers a multi-source compressor plant containing LM 2500 and frame 3 gas turbines as well as the noise emissions of gas-air coolers and dehydration equipment. The paper outlines further how potentials of noise reduction can be identified and how the noise impact of future projects can be simulated with the help of a computerized model.

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