H. T. D. Grigg, T. H. Hanley, B. J. Gallacher
Newcastle University, Newcastle, Tyne and Wear, UK
This work enunciates the principles of SAW design from a physical perspective, examining the standard engineering modelling assumptions in some detail. An integral form analytical expression based on 2D elastic isotropic theory is validated against a COMSOL Multiphysics® simulation, corresponding to the traditional COM approach. Next, a COMSOL model of the full 3D problem, including anisotropy, ...
Study & Modeling of 'Acoustic Matching Layers' for Ultrasound Imaging Probes Through Pulse-Echo FEM Simulation
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 ...
Ibragimov A., Koola, P.M.
Texas Tech University, Mathematics and Statistics, Lubbock TX, BSI One KBSI Place, East University, TX
Wave Carpet is a novel deep offshore wave-power floating system concept funded by the Office of Naval Research that will have low overall life cycle cost due to an integrated design and be rapidly redeployable. In this paper we numerically model the Wave Carpet motion using a coupled hydro-elastic time-domain solution. The major feature of the mathematical model is the presence of non ...
L. Martinelli, and A. Lamberti
Universita di Bologna, Italy
Objective of this contribution is to show how to implement the Mild Slope Equations with COMSOL Multiphysics. These equations are commonly used to study the propagation of waves in harbors. Some interesting features are presented, namely the use of weak terms (used for the modelling of the source term); the evaluation of a smooth phase gradient from the complex dependent variable; a robust ...
W. R. Kampinga, and Y. H. Wijnant
Reden, Hengelo, Netherlands
University of Twente, Enschede, Netherlands
Three efficient alternatives to the model in COMSOL’s thermoacoustics interface are presented. The higher efficiency of these models are explained from theory and are demonstrated by means of two examples.
R. C. Thiagarajan
ATOA Scientific Technologies Private Limited
Ultrasonic acoustic waves usually encounter interfaces with significant impedance mismatch in practical medical or industrial imaging applications. A transparent interface can help to improve the performance of medical and industrial imaging and overall innovative applications. Similarly, a broadband total reflection interface can help to improve the architectural or transportation barrier ...
F. Qian, L. Quan, X. Liu
Institute of Acoustics and School of Physics, Nanjing University, Nanjing, China
Previous research into acoustic omnidirectional absorber (AOA) has shown the feasibility of forming acoustic black hole to guide the incident wave into the central absorptive cavity. However, major restrictions to practical applications exist due to complexity of designing metamaterials and unchangeable working states. Here, we propose two cylindrical, two-dimensional AOA schemes based on ...
V. Romero-García, A. Krynkin, J.V. Sánchez-Pérez, S. Castiñeira-Ibáñez, and L.M. Garcia-Raffi
Centro de Tecnologías Físicas Acústica, Universidad Politécnica de Valencia, Valencia, Spain
School of Computing, Science & Engineering, University of Salford, Salford, United Kingdom
Depto. Física Aplicada, Universidad Politécnica de Valencia, Valencia, Spain
Instituto Universitario de Matemática Pura y Aplicada, Universidad Politécnica de Valencia, Valencia, Spain
The elastic and geometrical properties of Low Density Polyethylene (LDPE) foam are used in this paper to improve the attenuation properties of periodic arrangements of acoustic scatterers known as Sonic Crystals (SCs). A specific recycled profile of LDPE foam is used as elastic-acoustic scatterer. The acoustic spectrum of the single scatterer shows two attenuation peaks in the low frequency ...
S.L. Firebaugh, F. Roignant, and E.A. Terray
United States Naval Academy, Annapolis, Maryland, USA
Polytechnique Nantes, Nantes, France
Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
A fast, high-sensitivity detector is required for studies of environmentally relevant gases. Photoacoustic spectroscopy (PAS), an absorption spectroscopy technique in which absorption is detected as sound, is explored as a possible solution. A tuning-fork based PAS sensor is modeled using COMSOL. The model combines the acoustic and piezoelectric modules and also includes viscous damping. The ...
Y. Jing, and N. Xiang
Graduate program of Architectural Acoustics, School of Architecture, Rensselaer Polytechnic Institute, Troy, NY, USA
This note proposes a modified boundary condition for the diffusion equation model to predict the reverberation times and sound pressure distributions in enclosures.While previous diffusion equation models usually only have good performances for a certain range of absorption surfaces, the modified diffusion model yields more satisfactory results for both low and high absorption surfaces.An example ...