Showing results for: acoustic modeling Articles
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Structural acoustic modelling of three dimensional enclosed sound fields with active/passive piezoelectric networks
In this paper, analytical effort for modelling piezoelectric-structural acoustic interactions of sound transmission through a flexible smart panel into an enclosure is presented. A spherical wave is transmitted into a rectangular enclosure through a flexible panel, while piezoelectric patches, bonded on the panel, are used as actuators and /or passive dampers. The developed model accounts for ...
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The Significance of Sound Diffraction Effects in Predicting Acoustics in Ancient Theatres.
Abstract This paper examines the effect of sound diffraction in predicting sound propagation in ancient theatres. Few simulation studies to date concerning ancient theatre acoustics were conducted with diffraction effects. While sound diffraction effects in ancient theatres are known qualitatively, rarely have they been quantitatively documented. In this paper, the ancient theatre of Kourion in ...
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Acoustical characterisation of porous sound absorbing materials: a review
Over the past 50 years, the characterisation of porous sound absorbing materials has been of increasing interest to both the acoustic engineers and customers. It is particularly important that acoustic engineers are able to predict the acoustical behaviour of these materials to get a quantitative measure of the acoustic energy absorption. This paper reviews the relevant literatures over this ...
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Sound Absorption for All Saints Church Community Centre
Acoustic specialists, Sound Reduction Systems (SRS Ltd) were approached by All Saints Church with a view to treating the poor acoustics within their community centre. They had recognised that high levels of reverberation and echo were affecting the various groups that used the space, and were looking for a solution that was both effective and decorative. Initially, Mr Les Munns (Church Building ...
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Noise mapping of industrial sources
Noise is often one of the environmental variables where it seems more difficult to guarantee full compliance with legal limits in complex industrial situations and/or in other multi-source environments. This paper describes the application of noise mapping techniques to industrial sources, such as factories, power plants, wind farms, showing the potential of its use, both at the design stage as ...
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KLN Transducer Model Implementation Using Transfer Matrices
The Krinholtz, Leedom, and Matthaei transmission line model for acoustic transducers has been implemented on an IBM PC-XT computer using transfer, or "ABCD" matrices. Use of matrix formalism makes the programs easy to understand and allows quantities such as voltage, stress, strain and current to be readily calculated anywhere in the model. Previously difficult to model cases, such as open ...
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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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Computer-Optimized Design of Quarter-Wave Acoustic Matching and Electrical Matching Networks for Acoustic Transducers
We have developed an Iterative computer program to optimize the parameters for the acoustic matching layer(s) and the electrical matching network of a transducer for a minimum length of the impulse response. By including the Interactions between electrical and acoustic matching in our model » we have been able to significantly improve the quality of our transducers. A 3.65 MHz center ...
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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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Suspended particles in wastewater: their optical, sedimentation and acoustical characterization and modeling
Wastewater regulation and treatment is still a major concern in planetary pollution management. Some pollutants, referred to as particulate matter, consist of very small particles just suspended in the water. Various techniques are used for the suspended particles survey. Few of them are able to provide real-time data. The development of new, real time instruments needs the confrontation with ...
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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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Comparison of ISO 9613-2 vs Advanced Calculation Methods using Olive Tree Lab - Terrain
Abstract The process of performing an Environmental Impact Assessment includes the study of noise propagation. Often, the path from a noise source to a noise sensitive location involves complicated mechanisms of sound transmission. These mechanisms may relate to diffraction & reflections from obstacles (natural or man made), ground properties, and meteorological conditions. The International ...
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Doel Power Station - Case Study
Location: Belgium Project Date: 1996 Project: Doel Nuclear Power Plant Product: Spa Species: Herring and Sprat Electrabel approached Fish Guidance Systems Ltd in 1996 to help reduce the numbers of fish that were being drawn into Doel 3&4 intake, as the entrained fish were creating both environmental and operational issues for the station. The main species being affected ...
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Pulsar Sound Level Meter Achieves Germany’s PTB type approval
A Great Start to 2017 Pulsar Instruments Plc, leading manufacturer of occupational noise measurement products, has announced that the Model 45 Class 1 Sound Level Meter from its flagship Nova series has just received regulatory type approval from the Physikalisch- Technische Bundesanstalt (PTB). The German National Metrology Institute (PTB) is the highest federal authority and research ...
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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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Cirrus helps music festival keep the peace with local residents - Case study
With the summer season in full swing, people up and down the country are travelling far and wide to attend the year’s biggest music festivals. What better way is there to enjoy this glorious British summer than to venture off to enjoy a few days of fantastic music, surrounded by your favourite people? Music festivals are synonymous with British summer but as fun as they may be, they can, if ...
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Integrated noise calculation and evaluation according to the EU directive on environmental noise
The model data for acoustic calculations already contains essential characteristics for more in depth evaluation of the results (i.e. building heights, number of storeys, or ground space per storey). With additional information such as building usage and number of inhabitants, the evaluation and graphical representation of the results can be completed with only a small increase in expense. ...
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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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