G. C. Martins, P. R. Nunes, J. A. Cordioli
Federal University of Santa Catarina, Florianópolis, SC, Brazil
The use of piezoelectric materials in hearing aid loudspeakers, also called receivers, presents technical and economic advantages such as reducing the number of parts of the system and its manufacturing cost. However, the performance of such systems is still not competitive when compared to traditional electrodynamic loudspeakers. In order to achieve an appropriate performance, one option is to ...
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 ...
F. Botta, D. Dini, S. Gentili, G. Cerri
Dipartimento di Ingegneria Meccanica e Industriale, Università degli Studi di Roma Tre, Roma, Italy
Department of Mechanical Engineering, Imperial College London, London, United Kingdom
Turbomachines blades are forced by a load resulting from the interaction with the fluid. The consequent vibrations, and the associated fatigue phenomena, can give catastrophic failures and the reduction of the blades life. It could be increased if damping system are used. The piezoelectric materials has received considerable attention by many researcher for their potential application in the ...
Modeling of Noise Produced by Offshore Wind Turbines with Different Foundations and Effects on the Marine Environment - new
B. Marmo , I. Roberts 
Xi Engineering Consultants, Edinburgh, Scotland, UK
Vibration produced by offshore wind turbines during their normal operation transmits through the tower into the foundation where it interacts with the surrounding water and is released as noise. The noise produced by offshore wind turbines can be detected by fish and marine mammals and may lead to alteration of their behavior. Given that noise is emitted at the interface between the foundation ...
S. Hooshmand Zadeh
GE-Healthcare, Uppsala, Sweden
The approach of this project is Modeling a Coriolis Mass Flow-meter (CMF) bases on a Fluid-Structure Interaction (FSI) device. The "Coriolis mass flow-meter sensor" is modeled using COMSOL Multiphisics® simulation, the Acoustic-Shell Interaction physics interface and coupled by FSI physics interface to drive and simulate the sensor. The modeling and simulation are provided into two different ...
R. Costley, H. Diaz-Alvarez, M. McKenna, A. Miller
U.S. Army Engineer Research and Development Center, Vicksburg, MS, USA
Two finite element models have been developed to investigate the acoustic radiation from a Pratt truss train bridge. The first model was a time dependent structural model that determined the vibration response of the structure due to two wheels, representing a single axle, moving across the bridge at constant speed. This model was expanded to include multiple axles to represent a locomotive. The ...
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 ...
E. Gutierrez-Miravete, E.R. Marderness
Rensselaer Polytechnic Institute, Hartford, CT, USA
General Dynamics-Electric Boat, Groton, CT, USA
Industrial fluid systems often involve continuous piping loops. These systems consist of varying lengths of pipes and hoses connecting multiple components together. Fluid resonances can detrimentally affect the operation of fluid systems and components. This work used COMSOL to investigate the frequency and mode shapes of axial fluid resonances within a system of piping and components that ...
Empirical Model Dedicated to the Sensitivity Study of Acoustic Hydrogen Gas Sensors Using COMSOL Multiphysics®
A. Ndieguene, I. Kerroum, F. Domingue, A. Reinhardt
Laboratoire des Microsystèmes et de Télécommunications/Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
Laboratoire d’Électronique et des Technologies de l’Information, CEA, LETI Grenoble, France
Due to the increasing demand for hydrogen gas sensors for applications such as automation, transportation, or environmental monitoring, the need for sensitive and reliable sensors with a short response time is increasing. This paper presents an empirical model that studies the sensitivity of acoustic hydrogen gas sensors. A parametric study based on the variation of physical properties of ...
Using COMSOL to Support a Cost-Effective, Non-Destructive Evaluation Approach for Predicting Bolt Failure in Highway Bridges
A. Elyea, B. Doubek, G. Hubbard, and D. Ozevin
Department of Civil Engineering
University of Illinois at Chicago
The development of a quantitative nondestructive evaluation method, as an alternative to visual inspection, for inspecting pre-tensioned bolts in fracture critical bridges is presented. In order to understand the ultrasonic behavior of a wide variety of bolt geometries used in bridges, numerical models of nine different bolt geometries were developed. The numerical models included the ...