Holistic optimisation of noise reducing devices (original) (raw)
Related papers
Experimental evaluation and optimization of the acoustic properties of a noise barrier
2002
The latest Italian laws and U.E. Directives on noise pollution have prompt attention on the acoustic performances of materials; in this field noise barriers are among the most commonly used systems to reduce noise from roads or railways, also in urban areas. The paper illustrates the measurement results obtained at the Acoustics Laboratory of the University of Perugia on a new noise barrier sample. The barrier is made of perforated metal panels, filled with rockwool; there is also the possibility to insert in the barrier transparent panels, made of PMMA (Polimetylmetacrylate). Sound insulation properties have been measured in two coupled reverberating rooms, according to ISO 140-1[1], 140-3 [2], 717-1 [3], EN 1793-1 [4] and 1793-2 [5]; measurements have been carried out for two different barriers, one all made of metal panels, the other one with an insertion of PMMA panels. Sound absorption properties of the metal panels have been measured in a reverberating room, according to ISO/D...
COMPARISON OF EFFECTIVE NOISE BARRIERS IN TERMS OF ATTENUATION OF NOISE POLLUTION
Attenuating the noise is an ideal solution for the prevention of its pollution rather than its control. The process of attenuation can be achieved by providing noise barriers when it is unbearably louder. However, the provision of the barrier is cost effective as well as beneficial to human beings in the longer time. An analysis is created to achieve a potential noise barrier by constructing two noise barriers on a highway. The cost of a barrier can be described with known or quantifiable parameters such as barrier height, thickness, materials, initial costs, maintenance costs, replacement costs, etc. The benefits associated with a solution are defined by computable parameters such as sound absorption, sound reduction, insertion loss, and even intangible parameters such as its visual impact and environmental impact. In this study, the barriers used are of thatched leaves and concrete wall of specific size, and the reduction of traffic noise is being examined in terms of performance and construction cost and the suitability of each barrier is defined.
Attenuation of Noise Barrier in the Form of Enclosures
The installation of sound barriers is feasible enough to cause a significant decrease in noise pollution on roads. This study analyzes how the noise barriers affect the sound intensity level on roads. Noise level generated by a traffic flowing across open stream is compared to that of roads provided with sound barrier. Based on the field measurements an in-depth discussion is carried out to analyze the effectiveness of installing the barriers. The main objective of this paper is to predict the sound attenuation after the installation of the sound barrier on the road side. The priority of this project is to determine whether the installation of sound barriers is feasible enough to cause a distinct decrease in noise level on the roads.
ICSV 14 Cairns • Australia 9-12 July , 2007 ACOUSTIC PROPERTIES OF SOUND BARRIERS
2007
The purpose of this study was to optimize the acoustic properties of sound barriers for traffic noise applications. For a correct assessment of the noise produced by road vehicles, it is necessary to know every detail about the noise source. The main difficulty in the prediction of road traffic noise levels is the great variation in source conditions. First of all, the road vehicle type may vary from scooters and mopeds to various types of passenger cars to various types of trucks. Secondly, the characteristics of the road surface are of great influence on the tyre/road noise production. Finally, the noise produced by a single vehicle on a specific road surface is dependent on driving behavior and meteorological conditions.
Journal of the Acoustical Society of Japan (E), 1993
This paper deals with the development and the validation of a model used to evaluate the performance of parallel noise barrier configuration. These barriers are generally used to reduce the noise emitted by traffic roads. The formulation and algorithm used combine the multiple reflections occuring between the parallel barriers by the acoustical imagery method, and the barriers absorption by the modified Delany-Bazley impedance model. They also take into account parallel barriers with different heights, the ground effect, and a spectral sound power for various type of traffic noise. A complex summation between acoustical waves originating from a single source is used to obtain rigorously constructive and destructive acoustical interferences. This approach has been validated against systematic experimentations in controlled conditions in a semi-anechoic room. A case study is also presented which highlights the importance of applying absorbent materials on the barriers in terms of an increase in efficiency.
The Decrease of Noise with Acoustics Barriers
sra.ro
In this paper is presented the effect of one barrier of length infinite, situated along the speedway, having effect of acoustics protection over a populated area situated behind it. The barrier doesn't cover up an area of acoustic shadow, due to sound diffraction over the superior edge. It's made a parallel between two choice variants of acoustics barriers using the sound damping calculation, from behind of barrier.
Determination of Acoustic Properties of Noise Barriers
2016
Recently major improvements in the measurement methods for determining the in-situ values of noise barriers have been implemented. Laboratory and in-situ measurements have been compared. The results are not directly comparable, due to differences between the diffuse, omnidirectional sound field in the laboratory and the limited incidence angles that occur in the field. Additionally, new measurement methods have been developed by the University of Twente and SoundInSight, which are suitable to determine the acoustic properties of noise barriers in-situ, for any complex sound field.
Attenuation of Noise using Barrier in the form of Enclosure
The installation of sound barriers is feasible enough to cause a significant decrease in noise pollution on roads. This study analyzes how the noise barriers affect the sound intensity level on roads. Noise level generated by a traffic flowing across open stream is compared to that of roads provided with sound barrier. Based on the field measurements an in-depth discussion is carried out to analyze the effectiveness of installing the barriers. The main objective of this paper is to predict the sound attenuation after the installation of the sound barrier on the road side. The priority of this project is to determine whether the installation of sound barriers is feasible enough to cause a distinct decrease in noise level on the roads.
QUIESST Guidebook to Noise Reducing Devices optimisation
QUIESST Guidebook to Noise Reducing Devices optimisation, 2012
The aim of this guidebook is to become a reference tool for noise mitigation through a better use of Noise Reducing Devices (NRD) (e.g.: Noise Barriers or sound Absorptive Claddings). It targets all the stakeholders involved in NRD projects (designers, manufacturers, authorities, construction companies, maintenance companies...) and who are willing tooptimise the products and their use, either for rail or road noise mitigation. This guidebook is based on the final results and outcomes of the QUIESST research: it synthesizes this 3-years project and provides examples of best practices and recommendations on: • The effect of sound reflections in the far field by the definition and the determination of intrinsic far field performance indicators; • A new method for in-situ measurements of sound reflection and airborne sound insulation of NRD; • A better knowledge of the European NRD market through the first database comparing 400 different devices and their acoustic performances through...
A case study on acoustic performance and construction costs of noise barriers
Scientific research and essays
In the study, the barriers used for reducing traffic noise are being examined in means of performance and construction cost. First a noise prediction is made in the sample highway under certain traffic conditions in order to determine the noise barrier requirement and the results are confirmed by measurement. According to the noise prediction equations used in Turkey, Germany and Canada, the effects of heavy vehicle ratio, average traffic flow speed and hourly total vehicle quantity change on noise level and barrier requirement are examined, so assessment can be made for highways having different traffic specifications than the sample highway. In the continuation of the study, the working principle of noise barriers and effects of barrier position and height on reducing noise are researched in order to determine the construction costs of barriers in Turkey and Canada at different heights and made from different materials.