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 ...
F. Berger , T. Hummel , P. Romero , M. Schulze , B. Schuermans , T. Sattelmayer ,
 Lehrstuhl für Thermodynamik, TU München, Germany
 GE Power, Switzerland
Modern gas turbine systems for power generation are prone develop so-called thermosacoustic instabilities in the combustion chamber. Physically, these instabilities emerge as large amplitude pressure oscillations within the combustor, which are caused by constructive feedback interactions between the flame and the combustor's natural acoustic modes. The oscillations disturb the combustion ...
G. Zhu, E.M. Dede
Toyota Research Institute of North America, Ann Arbor, MI, USA
In previous work, a two-dimensional (2D) model was carried out to simulate the phononic band structure of a phononic crystal with square lattice structure, but this model did not account for the out-of-plane phonon dispersions . In fact, for 2D films used for coating materials, it is more interesting to understand their cross-plane properties. In this work, the phonon dispersion relation of ...
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 ...
M. A. G. Suijlen , R. J. Woltjer ,
 Novioscan, Nijmegen, Netherlands
For non-imaging wearable ultrasound applications Novioscan is developing piezoelectric MEMS transducers. These transducers consist of a large array of micromechanical silicon membranes with piezoelectrically actuated regions to generate an out-of-plane displacement causing a pressure wave in the adjacent medium. For a typical application of echo sounding in a human body such transducers operate ...
M. Swamy, L. J. van Lier, J. Smeulers
TNO, Delft, The Netherlands
In one of the screw compressor system, designed silencer was not optimal. A great challenge was the large variation in operating conditions, especially the variation of the molecular weight of the gas. There was need to optimize the silencer. This paper describes the acoustic modelling tools to optimize the acoustic performance of the silencer. Optimization steps carried out are based on the ...
Solving the Inverse Problem of Resonant Ultrasound Spectroscopy on Dumbbell-shaped Compression Samples Using COMSOL Multiphysics®
M. C. Golt
U.S. Army Research Laboratory*, Aberdeen Proving Ground, MD, USA
*Contracted through Dynamic Science, Inc.
The dumbbell geometry is an ideal shape for testing the compressive strength of advanced ceramic materials. This paper details the combined use of COMSOL Multiphysics® and LiveLink™ for MATLAB® for determining the elastic properties of dumbbell-shaped samples by measuring their acoustic resonance frequencies. Degenerate bending modes which are sensitive to inhomogeneities or machining defects ...
G.D. Cole, M. Aspelmeyer, and I. Wilson-Rae
University of Vienna, Vienna, Austria
Technical University Munich, Munich, Germany
Micro-and nanoscale mechanical resonators have recently emerged as ubiquitous devices for use in advanced technological applications, for example in mobile communications and inertial sensors, and as novel tools for fundamental scientific endeavors. We report a significant advancement towards understanding and controlling support-induced losses through the demonstration of an efficient numerical ...
M. A. B. Andrade , N. Pérez , J. C. Adamowski ,
 Instituto de Física, Universidade de São Paulo, São Paulo, SP, Brasil
 Centro Universitario de Paysandú, Universidad de la República, Paysandú, Uruguai
 Departamento de Engenharia Mecatrônica e Sistemas Mecânicos, Escola Politécnica, Universidade de São Paulo, São Paulo, SP, Brasil
Este trabalho apresenta a simulação numérica de um sistema de levitação acústica para manipulação de partículas em ar. O sistema de levitação consiste de dois transdutores de ultrassom e um refletor de face plana. Através da simulação é calculado o potencial da força de radiação acústica que atua numa esfera. Os resultados da simulação são verificados experimentalmente através da comparação da ...
K. Kryniski , A. Trangard ,
 ABB Corporate Research, Västerås, Sweden
In addition to using advanced functions built-into the engine of the COMSOL Multiphysics® software, we integrate dynamic properties of rotating components that are measured or pre-computed. Here, it is shown how to integrate fluid-film characteristics and take advantage of post-processing and graphics to present the results to the customers using the Cloud. COMSOL® simulations of rotor-bearing ...