University Paris 13 - Math. dpt.
This note is devoted to a domain decomposition method solving the Helmholtz equation in the frequency domain. We need to perform this global computation as a sequence of local computations, each computation being performed on a single subdomain, without any knowledge of the geometry and meshing of the other subdomains. This is useful when the global geometry is too big to be stored in a single ...
Beam Structure As an Acoustic Wave Sensor: A Study of the Effect of Sensor Design on Its Sensitivity to Noise
F. Akasheh, A. Biddle, W.S. Shepard Jr., and B.B.B. Zhang
Tuskegee University, Tuskegee, AL, USA
University of Alabama, Tuscaloosa, AL, USA
The detection and identification of the location of a sound source is commonly done using arrays of microphones. A recent new alternative approach has been proposed which involves the use of continuous structures, such as beams or plates, as acoustic wave sensors. The sound wave impinging on the surface of the structure causes it to vibrate and the measured surface displacements can then be used ...
J. Ratnieks, A. Jakovics, and J. Klavins
University of Latvia
Although we know the physics inside a media where the sound waves propagate, determination of material\'s or structure\'s sound reduction index is not an easy task. The lack of good engineering solutions proves the point. The only reliable way to calculate the sound reduction index is to carry out an experiment.Therefore, the aim of this study is to develop a mathematical model that can ...
Acoustic Attenuation Performance Of Helicoidal Resonator Due To Distance Change From Different Cross-Sectional Elements Of Cylindrical Duct
Poznań University of Technology, Poznań, Poland
This work presents acoustic attenuation performance of helicoidal resonator due to distance change from different cross-sectional elements of cylindrical duct. The helicoidal resonator properties are described mainly in in infinite long cylindrical duct. For practical applications it is important to know the limits of use of this solution. This paper describes how the helicoidal resonator should ...
The Significance of Coupling in 3D Modelling of Acoustic Wave Propagation in a Cavity Containing Air and Porous Absorbent
L. Kelly, Y.W. Lam, and M. Avis
Research Institute for the Built and Human Environment, University of Salford
This study examines acoustic wave propagation in air and porous media in three dimensions using numerical models; in particular it looks at the significance of the coupling effect between the air and porous layer. The numerical model consist of a layer of air and a layer of porous absorbent which are modelled as equivalent fluid and are characterised by complex characteristic impedance based ...
P.R. Basha, B. Mishra, and A. Zachariah
School of Electronics Engineering, VIT University, Vellore, Tamil Nadu, India
The realization of miniature SAW device is compatible on CMOS device for mobile and wireless communication system has become very important in recent years. Acoustic wave propagation along the surface of a piezoelectric material provides a means of implementing a variety of signal processing devices at frequency ranging from several MHz to a few GHz. In this work, a Miniature SAW device is ...
Zeugin Bauberatungen AG
Especially in large offices and call centers the noise pollution of Employees and mutual disturbance is an actual problem. The existing distribution of the sound pressure level in a range of frequency from 100 – 250 Hz show significant noise pollution also at remote workplaces for the current state of the examined large office. For improvements the influence of compact wideband sound ...
D. P. Elford, L. Chalmers, F. V. Kusmartsev, and G. M. Swallowe
Department of Physics
The results of numerical modelling of sonic crystals with resonant array elements are reported. The acoustic band structure and transmission characteristics of such systems have been computed with the use of finite element methods. An existence of a separate attenuation mechanism associated with the resonant elements, which increases performance in the lower frequency regime has been ...
Acoustics@ MBD Consultants LLC.
Applied 2D scale model presents a semi-realistic design or a microphone and shows the main mechanical, magnetic coil and electrical parts. Some non-vital elements are excluded for better focusing on acoustic properties of the microphone. The models are tested for frequency response, acoustic power loss, directivity patterns as well design and materials optimization. Based on 2D model analysis ...