N. Chowdhury, Z. Liao, and L. Zhao
Department of Electrical & Computer Engineering, Ryerson University, Toronto, ON, Canada
Department of Architectural Science, Ryerson University, Toronto, ON, Canada
Acoustic wave propagation due to the breakage or slippage of reinforced wire in water-filled prestressed concrete cylinder pipe (PCCP) attracts interest in non-destructive pipe testing. Current practice of acoustic emission (AE) detection and wire-break related events (WRE) recognition is based on field data analysis. This work deals with the theoretical investigation of WRE signal from ...
K. Mcilhany, and J.C Hernandez
U.S. Naval Academy, Annapolis, MD, USA
Acoustic Imaging of hand movement is being studied with COMSOL and Matlab. A hardware implementation is being pursued that will be an array of 16x16 ultra-sonic speakers placed in a grid facing a similar grid of 16x16 microphones, operating at 40kHz. COMSOL is used to repeatedly calculate the diffraction pattern from a small scattering center, approximately 1.0cm in diameter. In conjunction ...
Y.F. Wang, Y.S. Wang, L. Wang
Institute of Engineering Mechanics, Beijing Jiaotong University, Beijing, China
Department of Mechanical Engineering, Østfold University College, Halden, Norway
We show in this paper that by careful design of the geometry of the resonators, complete bandgap with relatively low center frequency can be obtained for 2D and 3D Phononic Crystals with resonators. The generation of the bandgap is due to the local resonance of the unit cell. Spring-mass and spring-pendulum models are developed to predict the boundaries of the complete bandgap. The predicted ...
B. Baumann, M. Wolff, J. Hirsch, P. Antonis, S. Bhosle, and R. Valdivia Barrientos
Hamburg University of Applied Sciences, Hamburg, Germany
Philips Lighting, Eindhoven, The Netherlands
LAPLACE, Université de Toulouse and CNRS, Toulouse, France
National Institute of Nuclear Research, Salazar, Ocoyoacac, Mexico
High intensity discharge lamps can experience flickering and even destruction, when operated at high frequency alternating current. The cause of these problems has been identified as acoustic resonances inside the lamp’s are tube. Here, a finite element approach for the calculation of the acoustic response function is described. The developed model does not include the plasma dynamics.
J. Muraoka, and T. Suzuki
Yamagata Research Institute of Technology
The traveling wave ultrasonic vibration disks for dispersion of particles were designed by using of FEM analysis. The vibration disks are required specific vibration pattern, which contains three nodal lines. The vibration disk thickness was calculated to be matched the resonance frequency of bolted langevin type transducer and the specific vibration pattern. The alignment of the transducer was ...
Lind, R.J., Abedian, B.
Department of Mechanical Engineering Tufts University, Medford, Massachusetts
This presentation is a numerical study of fluid flow around a two-dimensional rigid flapping plate and its effects on the resultant transient heat transfer effects on the solid interface. In this study, a flat inflexible thin plate surrounded by air undergoes sinusoidal angular motion from one end while the other end is kept stationary, simulating a flapping motion. The two-dimensional ...
D. Borelli and C. Schenone
DIPTEM, University of Genova, Genova, Italy
The present paper describes the results of a Finite Element Model used to analyze sound propagation in lined ducts. By means of a numerical model it was possible to predict the insertion loss inside rectangular lined ducts in a frequency range from 250 Hz to 4000 Hz. The model was validated by a comparison with experimental data obtained in accordance to ISO 11691 and ISO 7235 standards. The ...
M. Herring Jensen
Widex A/S, Vaerloese, Denmark
In this study we model the sound attenuation properties of a hearing aid earmold tube. The model includes thermoviscous acoustic effects and it couples structural vibrations to the external acoustic field. Moreover, the finite element domain is coupled at two boundaries with an electroacoustic model of a hearing aid and an acoustic 2-cc coupler.
O. Legrani, O. Elmazria, S. Zhgoon , L. Le Brizoual, and A. Bartasyte
Institut Jean Lamour, CNRS-Nancy University, Vandoeuvre lès Nancy, France
Moscow Power Engineering Institute, Krasnokazarmennaja, Moscow, Russia
Institut des Matériaux Jean Rouxel, Université Nantes, CNRS, Nantes, France
In this work, the theoretical study for the realization of waveguiding layer acoustic waves devices based on AlN/IDT/ZnO/Silicon structure using the modeling software COMSOL Multiphysics (2D) is presented. The effect of thicknesses of AlN and ZnO thin films on the evolution of frequency response, phase velocity and electromechanical coupling is studied. The adequate structure is determined for ...
C. Peyrega, and D. Jeulin
Center of Mathematical Morphology, Mines ParisTech, Fontainebleau, France
This study is a part of the Silent Wall ANR project, to which the Center of Mathematical Morphology is associated. Its main objective is to build an acoustical and thermal insulating system for buildings, composed of fibrous materials. The material is composed of two phases: the fibrous network and the air surrounding it. At the microscopic scale the absorption of the acoustic wave is mainly due ...