N. R. Mahesh, and P. Nair
SSN College of Engineering
Tamil Nadu, India
Acoustic metamaterials are structured materials of negative mass density or negative bulk-modulus or both of them. Materials are tailored in sub-wavelength dimensions so as to get these negative properties. This paper compares the result of an experimental investigation of acoustic metamaterial with negative bulk-modulus to its COMSOL modeling. The resonance characteristics of single ...
J. McKenna, M. McKenna, S. Yushanov, J. Crompton, and K. Koppenhoefer
U.S. Army Engineering Research and Development Center
ACES of Columbus, LLC, Columbus, OH, USA
The propagation of shear (S) and compression (P) waves within the earth allows geologists to track seismic events and to identify subterranean structure. This work shows the strong effect of including the variation of wave speed through the top thirty meters of the earth. By including this variation in material properties, the wave arrival time and frequency content agree with experimental data. ...
Y. Davletshin, J. C. Kumaradas
Ryerson University, Toronto, ON, Canada
Photoacoustic (PA) imaging has matured into a clinical modality for tissue imaging and functional cancer cell research. It uses a pulsed laser to irradiate a region and generate a thermally-induced acoustic pressure wave that can be collected by an ultrasound transducer. The optical absorption/PA contrast of the region of interest can be enhanced by the use of plasmonic nanoparticles. The ...
J. H. Lee
Department of Mechanical Engineering, American University of Sharjah, Sharjah, UAE
The idea of application as a hearing device based on a parasitoid fly, Ormia ochracea has been studied extensively recently. This paper addresses another possible application as an underwater directional sensor. In order to study the feasibility of the application, it is necessary to investigate the feasibility of the underwater application of the directional sensor based on the hearing ...
S. L. Pinjare, V. S. Nagaraj, S. N. Savitha, S. Kesari, M. S. Sagar, and K. R. Roshan
Nitte Meenakshi Institute of Technology
The MEMS microphone is also called microphone chip or silicon microphone. The pressure sensitive diaphragm is etched directly into a silicon chip by MEMS techniques and is usually accompanied with integrated preamplifier. Most MEMS microphones are variants of the condenser microphone design. The MEMS microphone has been successfully fabricated and tested in an anechoic chamber. The microphone ...
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 ...
Study & Modeling of 'Acoustic Matching Layers' for Ultrasound Imaging Probes Through Pulse-Echo FEM Simulation - new
Esaote SpA, Florence, Italy
Ultrasound Imaging probes are specific devices that require a very detailed design of acoustic impedance match for the stack of layers that form the probe head (1,3). These are typically made of silicone rubber, special epoxy resins, polyurethanes and, of course, piezoelectric materials. The acoustic impedance, measured in Rayls, have to be matched similarly to an electric circuit (2), from a ...
L. Fromme , J. Waßmuth , D. Wehmeier ,
 Bielefeld University of Applied Sciences, Bielefeld, Germany
The knowledge of the acoustical transfer paths in active noise control systems is very important for the performance of the system. Unfortunately, simulation is challenging since even simple configurations require comprehensive experience in physics and modeling. Two test setups were chosen for basic investigations on modeling, simulation and validation. The first results presented here are ...
J. P. Sandoz, J. M. Kissling
Institute of Applied Microtechnology, La Chaux-de-Fonds, HE‐ARC, Switzerland
In this contribution we present a COMSOL Multiphysics® example of a disk piezoelectric ceramic transformer (D-PT) coupled with a bipolar NPN transistor to form an auto-oscillator. The comparison between the simulations and the measurements made on our prototype are found to be in good agreement. Having at our disposal a large number of homogenously poled disks, we decided to build and to ...
F. Mbailassem , Q. Leclere ,
 LVA - INSA de Lyon, France
This paper introduces an efficient model to describe energy dissipation in acoustic. When the propagation domain has hard wall boundary conditions only viscous and thermal losses happen and are completely described by the so-called Full Linearized Navier-Stokes model (FLNS) which is implemented in thermoacoutics interface using the COMSOL Acoustics Module. This model defined by a set of ...