noise modelers Articles
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Traffic noise assessment at National Highway 28 in India using FHWA model
Federal Highway Administration's Traffic Noise Model (TNM) versions 2.1 and 2.5 have been analysed to determine their functionality and accuracy in the Indian context. Each of the resulting changes between predicted noise levels and observed noise levels are analysed, and the agreement diagram is developed between observed noise levels with predicted noise levels. During the measurements, traffic ...
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Noise Modelling of Reflections and Façade Corrections
Sound we hear all around us comes at us from all directions. Much of the sound we hear may not actually be visible but may have been reflected off structures and buildings or any surface that is hard and rigid. When a sound engineer has a task of building a noise model containing sources such as vehicle movements on road surfaces or sources related to industrial equipment, they may need to take ...
By WKC Group
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Prediction of noise from track systems
A practical approach is presented for the prediction of noise level generated by a track system at the design stage of a tracked vehicle. Rayleigh's surface integral is adopted for relating the acceleration of a track link chain in the time-domain to the radiated acoustic pressure of the exterior noise. The sound pressure levels of the noise generated by the vibrating track system are calculated ...
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Modelling of friction-induced noise of timing belt
This article presents a study of friction noise of timing belt. A historical review is given and an analytical model is proposed to illustrate friction noise generation mechanism. The analysis suggests that the friction noise of timing belt is due to the friction-induced mode coupling of tooth bending modes. A new mechanism of instability for tooth slippage is proposed and used to correlate ...
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WKC at Landmark IAIA Event
20 Years of IAIAsa - what are we achieving, where are we heading? The 20th Annual Conference of the South African affiliate of the International Association for Impact Assessment (IAIA) was recently held in the midst of the scenic uKhahlamba Drakensberg National Park, a UNESCO World Heritage Site. As well as providing sponsorship for the event, WKC sent a delegation consisting of Marc ...
By WKC Group
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Noise mapping of roads in England
Landmark Solutions, the UK provider of geospatial information, solutions and services, was selected by DEFRA as the prime contractor to carry out noise mapping for the Potteries area of the West Midlands. This work forms part of the Government’s National Ambient Noise Strategy (NANS), part of which is focused on mapping noise levels from roads, railways, aircraft and industrial sites across ...
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A survey of wheel tyre cavity resonance noise
Noise, vibration, and harshness (NVH) are synonymous with quality factor in automotive engineering. This quality factor is influenced by the internal noise such as engine noise, and external noise such as aerodynamic noise and tyre–road noise. Whereas many studies have been done to identify noise sources and reduce the noise and vibration transmission from the engine and aerodynamic sources to ...
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Traffic Noise Mapping in Chile
Against this backdrop of economic change, a two-year study got underway across three Chilean cities led by the Univ. Austral. and was supported by the Chilean Ministry of the Environment. Academically titled: “Development and analysis of noise maps of three urban agglomerations using modeling software”, the study concentrated on the Chilean cities of Coquimbo – La Serena, ...
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Queensland Rail – An example in effective noise mapping and noise control implementation for existing rail operations
There is an increasing trend in the world today to model noise impacts of city-wide infrastructure such as rail, road and industrial activities. This is particularly true of the European Union, which sought to produce an integrated approach across member states to predict city-wide long term average noise levels. The outcome of such an exercise usually results in production of noise contour ...
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Why We Need Noise Prediction Modelling
Establishing the noise environment of a location would typically consist of conducting noise measurements using a sound level meter. Multiple locations in which to measure from may be necessary to account for different but important receptors to noise, as well as frequent measurements if one or more noise sources vary over time. But what approach do you take if the impact of a noise source you ...
By WKC Group
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Noise control in building design planning is a sound investment
Jochen Schaal, managing director of SoundPLAN GmbH and Michel Rosmolen, director of SoundPLAN Asia, outline developments in room acoustics to improve our environment Demand for architectural services in India is increasing, with government initiatives like the Smart Cities Mission[i], encouraging development in the sector. This project aims to harness technology to improve urban development, ...
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Buying Noise Measurement Equipment: how to cut costs, not quality
At a time when budgets are under strain, the Pulsar Model 14, ultra-simple digital sound level meter offers a compliant, reliable, yet affordable noise meter. It is the preferred choice of employers looking for a meter for general purpose use whilst meeting the “Noise at Work” Regulations and the requirements of IEC 61672 to Class 2. The Model 14 retails at £260.00 and provides ...
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Gulf Ecology Merger
WKC Group Merger with Gulf Ecology We are pleased to announce the recent merger between WKC Group and Gulf Ecology. Gulf Ecology is a successful, niche consultancy business based in Dubai offering regional marine ecology and terrestrial ecology services. In combining resources, WKC is now able to offer terrestrial and marine ecology services throughout the Arabian Gulf, and similarly, we are keen ...
By WKC Group
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Predicting acoustic transmission loss through laminated glass with air and porous layers
This study analyses the sound transmission characteristic of various laminated glass designs with application to motor vehicles. The porous interlayer in the laminated glass is filled with polyvinyl butyral (PVB) that serves as an acoustic damper. To model the physics behind the sound transmission losses of the fluid, solid and porous layers, acoustic noise transfer matrices are used to relate ...
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The use of step and pulse tests to design activated carbon adsorption columns for recovery of copper ions from aqueous industrial effluents
Dynamic experiments were carried out on the adsorption of copper ions in a laboratory packed bed of activated carbon. Both pulse and step change inputs were used. Measurements were reproducible and replicate measurements furnished nearly identical parameters for a conventional heterogeneous model of the activated carbon bed, assuming a Langmuir adsorption isotherm. Bed depth had little effect on ...
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Modelling of broadband noise radiated by an airfoil-application to an axial fan
In this paper, a modelling of the broadband noise radiated by an axial subsonic fan is presented and validated. It is an extension of Amiet's model predicting the broadband noise generated by an isolated airfoil. Two sources are analysed, incident turbulence interaction noise and trailing edge noise. It shows the dominance of the leading edge noise. The broadband noise directivity for axial fans ...
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Parameter identification of river water quality models using a genetic algorithm
For solving the multi-parameter identification problem of a river water quality model, analytical methods for solving a river water quality model and traditional optimization algorithms are very difficult to implement. A new parameter identification model based on a genetic algorithm (GA) coupled with finite difference method (FDM) was constructed for the determination of hydraulic and water ...
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Vehicle interior noise transfer function predictions applying semi-analytical, finite element and boundary element approaches
The vehicle interior noise transfer functions that affect structure-borne paths critically are analysed using three different numerical techniques, namely the fast numerical modelling, finite element and boundary element. Firstly, the interior noise transfer function predictions employing the fast numerical modelling for simple rectangular cavity model are validated by comparison to the classical ...
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A computational fluid dynamics study of crosswind effects on vehicle A–pillar aero–acoustics
The surface pressure fluctuations due to the flow separation in the A–pillar region on the front side windows of a passenger car is a dominant source of aerodynamic noise. Aerodynamically generated noise adversely affects vehicle occupant's comfort and safety (due to fatigue caused by long time noise exposure). The size and magnitude of the A–pillar flow separation mainly depend on the local ...
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Numerical analysis of automotive disc brake squeal: a review
This paper reviews numerical methods and analysis procedures used in the study of automotive disc brake squeal. It covers two major approaches used in the automotive industry, the complex eigenvalue analysis and the transient analysis. The advantages and limitations of each approach are examined. This review can help analysts to choose right methods and make decisions on new areas of method ...
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