Numerical Study on Shear Horizontal Electromagnetic Acoustic Transducers for Generation of Ultrasonic Guided Waves for Absorber Tubes used in Concentrated Solar Plants
L. Cheng, A. Mohimi, M. Kogia, V. Kappatos, C. Selcuk, T.-H. Gan
Brunel Innovation Centre, Brunel University, Uxbridge, UK
Absorber tubes are one of the most critical components of parabolic trough Concentrated Solar Plants, which is very likely get damaged such as crack and mass loss. Therefore, the monitoring of their structural health via Non-Destructive Testing (NDT) techniques is regarded as essential for preventing them from being significantly defective and thereby reducing maintenance cost. Non-contact ...
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 ...
On The Use of a Diffusion Equation Model for Sound Energy Flow Prediction in Acoustically Coupled Spaces
Y. Jing, and N. Xiang
Rensselaer Polytechnic Institute, Troy, NY, USA
This paper studies sound energy flows through an aperture across two coupled spaces using a diffusion equation model. The so-called double sloped sound energy decay is believed to be caused by the sound energy exchange through the aperture coupling the two rooms. The room diffusion equation is first solved by COMSOL, then the time dependent energy flow is visualized via COMSOL arrow plotting, ...
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 ...
G. Rosi, L. Teresi, A. DiCarlo, and F. dell'Isola
LaMS - Università degli Studi Roma Tre, Roma, Italy
Università degli Studi di Roma "La Sapienza", Roma, Italy
Liquid crystals - as all liquids - are generally modelled as incompressible media. In fact, mass-density changes occurring in these mesophases are minuscule and inconsequential in most regimes of interest. However, liquid crystals exhibit also phenomena that call for a more refined theory. In particular, it is experimentally well established that the Fréedericksz transition - i.e., the sudden ...
S. Carcangiu, B. Cannas, M. Usai, and G. Concu
Department of Electric and Electronic Engineering, Cagliari, Italy
Department of Structural and Infrastructural Engineering and Geomatics, Cagliari, Italy
An experimental program has been developed, with the purpose of evaluating the reliability in building diagnosis and characterization of an integrated analysis of several parameters, associated with acoustic waves propagating through the material. The Direct Transmission Technique has been applied. In this paper we developed a numerical model using the Transient Acoustics-Piezoelectric ...
M. Zebian[1,2], J. Hensel , and T. Fedtke
Physikalisch-Technische Bundesanstalt, Braunschweig, Germany
International Graduate School of Metrology, Braunschweig, Germany
Otoacoustic emission (OAE) tests provide an objective examination of the cochlear function. However, the validity of OAE tests is affected negatively by calibration errors. This report sheds light on the evanescent waves arising at the interface between the OAE probe and the ear canal, and analyses the impact of minor eartip modifications on the acoustic length estimation of ear canals, using ...
Modeling and Experimental Verification of the Power Transfer and Thermal Characteristics of Piezoelectric Transformers Subjected to Combined Mechanical and Electrical Loading
S. Tuncdemir, W.M. Bradley
Solid State Ceramics, Williamsport, PA, USA
QorTek, Williamsport, PA, USA
A piezoelectric transformer allows purely mechanical transfer and scaling of electrical energy via simultaneous utilization of both the direct and converse piezoelectric effects. This mechanical energy transfer enables a wide range of functional differences from typical magnetic-based electrical power transformers. Comparing to their electromagnetic counterparts, piezoelectric transformers are ...
A-S. Moreau, H. Lissek, and R. Boulandet
EPFL-STI-IEL-LEMA, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
In this paper, the underlying concept of electroacoustic absorbers is studied with the help of Comsol Multiphysics® Acoustics Module. Among the different ways to obtain variable acoustic properties on an electroacoustic transducer's voicing face, there is the shunting of the transducer's electrical input. With such shunt devices, the acoustic impedance that the transducer's membrane presents ...
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 ...