J. Smeulers, N. Gonzalez Diez
TNO, Delft, The Netherlands
Turbo compressors can generate high frequency tonal noise, causing nuisance in the environment. As the noise is radiated from the piping, a silencer is installed between the compressor and the pipe system. Commonly an absorption silencer is applied, which is a vessel that contains acoustic absorption material. Due to high flow velocities and vibrations the absorption material may be blown out of ...
A. van Wijhe, W. de Jong
Process & Energy, 3mE, TU Delft, The Netherlands
A COMSOL Multiphysics® model was made to design a mechanical amplifier and radiation plate for the emission of high intensity 40.5 kHz ultrasound to air by means of a Langevin type transducer usually applied in cleaning baths for example. In this work, ultrasonic irradiation is aimed at acting on flue gas containing fine particulate matter to realize a shift to higher effective particle sizes as ...
An Investigation of Loudspeaker Simulation Efficiency and Accuracy Using i) A Conventional Model, ii) The Near-To-Far-Field Transformation and iii) The Rayleigh Integral
R. Christensen, U. Skov
 iCapture ApS, Roskilde, Denmark
Simulation on loudspeaker drivers require a conventional fully coupled vibro-acoustic model to capture all effect. An accurate vibroacoustic model can be time-consuming to solve, especially in 3D. In practical applications, this results in poor efficiency concerning the decision-making process to move on to the next simulation model. To overcome this the loudspeaker designer can use either the ...
H. Bruus, P.B. Muller, R. Barnkob, M.J.H. Jensen
Technical University of Denmark, Kongens Lyngby, Denmark
COMSOL, Kongens Lyngby, Denmark
We have simulated the ultrasound-induced acoustophoretic motion of microparticles suspended in an aqueous solution. The full first-order thermoviscous acoustics equations have been implented on a rectangular microfluidic 2D domain excited with an ultrasound field tuned to resonance near 2 MHz. The micrometer-thin but crucial viscous boundary layers at the rigid walls have been fully resolved. The ...
NATO Undersea Research Centre, La spezia
In water we can’t see far, because light and electromagnetic waves are absorbed over relatively short distances. In contrast, sound travels very well in water In fact it is well known that marine mammals rely on sound for communication over large distances, and some of them even use sound to locate their target while hunting. In this presentation we provide an overview of the principles of ...
M. Zampolli, N. Malm, and A. Tesei
NURC NATO Research Centre, La Spezia, Italy
COMSOL AB, Stockholm, Sweden
Perfectly matched layers (PML) are an efficient alternative for emulating the Sommerfeld radiation condition in the numerical solution of wave radiation and scattering problems. The key ingredient of the PML formulation is the complex scaling function, which controls the anisotropic damping of the PML. The objective of this study is to propose a modified complex scaling function capable of ...
Simulation of Acoustic Energy Harvesting Using Piezoelectric Plates in a Quarter-Wavelength Straight-Tube Resonator
B. Li, J.H. You
Southern Methodist University, Dallas, TX, USA
An acoustic energy harvesting mechanism at low frequency (~200 Hz) using lead zirconate titanate (PZT) piezoelectric cantilever plates placed inside a quarter-wavelength straight-tube resonator has been studied using COMSOL Multiphysics 4.3 and compared with experimental data. When the tube resonator is excited by an incident wave at its acoustic eigenfrequency, an amplified acoustic resonant ...
Karthi Pradeep, G. Suresh, V. Natarajan,
National Institute of Technology, Tiruchirappalli, Kerala, India
Naval Physical & Oceanographic Laboratory (NPOL), Kochi, Kerala, India
A Helmholtz resonator type acoustic sensor has been designed using analytical method and finite element modeling software, COMSOL Multiphysics®. The acoustic sensor is an aluminium double frustum, hour glass, shaped with the resonator at the bottom and an acoustic horn above to amplify the incoming acoustic signal. The horn provides a broad amplification of the incoming acoustic signal while the ...
N. Alcheikh, C. Ayela, I. Dufour
Univ. Bordeaux, IMS Lab, Pessac, France.
Electrostrictive polymers have been of significant interest over the last years for energy harvesting. Principle is based on the conversion of a mechanical deformation into electricity. The stored energy basically depends on the mechanical strain induced into an electrostrictive polymer by the mechanical resonant vibration of a microcantilever supporting the electrostrictive layer. In this work, ...
Y.L. Rao, and G. Zhang[1-3]
 Micro/Nano Bioengineering Laboratory, Department of Biological and Agricultural Engineering, The University of Georgia
 Nanoscale Science and Engineering Center, The University of Georgia
 Faculty of Engineering, The University of Georgia
Integration of surface acoustic wave (SAW) devices with nanostructures has gained interest in the development of sensors with high sensitivity. To better design nanostructure integrated SAW devices, it is essential to model three dimensional (3-D) SAW devices and analyze the wave propagation characteristics in nanostructure-enhanced SAW devices. In this work, a 3-D finite element model of ...