Mitsubishi Turbocharger & Engine Europe, Almere, The Netherlands
This study presents a rotordynamic analysis of a rotor on hydrodynamic bearings using COMSOL Multiphysics®. In this paper, the complexity of the model is gradually increased. Starting point of the analysis is the modal analysis of the rotor in free-free conditions. A Reynolds model is set up to predict the film pressure distribution under shaft loading. Due to the cross coupling terms of the ...
Lamb Waves and Dispersion Curves in Plates and It’s Applications in NDE Experiences Using Comsol Multiphysics
P. Gómez, J. P. Fernandez, and P. D. García
Hydro-Geophysics & NDE Modeling Unit
University of Oviedo
In this paper, a model for numerically obtaining lamb wave modes and dispersion curves in plates is presented. It is shown that COMSOL Multiphysics can be employed to simulate the behavior of guided waves in dispersive plates, which is useful for NDE applications. A two dimensional steel plate (4x0.1 meters) is excited with a space-time impact point source. To model the point source, we use ...
Simulation of Acoustic Energy Harvesting Using Piezoelectric Plates in a Quarter-Wavelength Straight-Tube Resonator
B. Li, J.H. You
Southern Methodist University, Dallas, TX, USA
An acoustic energy harvesting mechanism at low frequency (~200 Hz) using lead zirconate titanate (PZT) piezoelectric cantilever plates placed inside a quarter-wavelength straight-tube resonator has been studied using COMSOL Multiphysics 4.3 and compared with experimental data. When the tube resonator is excited by an incident wave at its acoustic eigenfrequency, an amplified acoustic resonant ...
Esaote SpA, Florence, Italy
Pulse-echo FEM simulation is seldom found in literature for ultrasound imaging array probes, since the complete modeling of such device is extremely complicated. Nevertheless, the 2D FEM described in the present work was successful, thanks to the following design procedure (see figure): Two piezoacoustic models were employed, one for transmission of the pressure wave into the acoustic domain, ...
C. Van der Woude, and S. Narasimhan
University of Waterloo, Waterloo, ON, Canada
This paper presents a study of a wind turbine subjected to wind and seismic loading, carried out using COMSOL Multiphysics. The dynamic properties and response of wind turbine structures are of interest, as recent developments in wind energy have led to the design and construction of increasingly large and flexible turbine structures. A typical turbine structure model was created in ...
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 2D ...
L. Spicci, and M. Cati
The present paper describes the development of a full FEM model for linear array high performance 5MHz ultrasound imaging transducer. As a preliminary design, a mono dimensional electro-acoustical KLM model was realized, then the complete FEM was developed and optimized. The optimized transducer was manufactured, so that agreement between transducer measured performances and simulation results ...
B. Baumann, J. Schwieger, M. Wolff, F. Manders, J. Suijker
Hamburg University of Applied Sciences, Hamburg, Germany
Philips Lighting, Turnhout, Belgium
High-intensity discharge lamps will in the foreseeable future be important light sources despite a growing market share of LEDs. Cost and energy efficient high frequency (300 kHz) operation is hampered by the excitation of acoustic resonances inside the arc tube, which results in low frequency (10 Hz) light flicker. Our aim is to calculate the acoustic streaming velocity field, which is related ...
A. Cavuto, G.M. Revel , M. Martarelli , F. Sopranzetti 
Università Politecnica delle Marche, Ancona, Italy
Università e-Campus, Novedrate (CO), Italy
A 2D axisymmetric model was considered in order to evaluate the propagation paths of the ultrasonic waves generated inside an aluminum plate sample due to a rapid thermal expansion produced by laser pulse. Laser Doppler Vibrometer is used to experimentally validate the numerical results of the wave propagation in the material. The presented numerical model is able to identify directivity patterns ...
A. Ravi, R. Krishna, J. Christen
Arizona State University, Tempe, AZ, USA
Capacitive MEMS sensors offer high spatial resolution, sensitivity and good frequency response. In this paper, we present a circular membrane capacitive MEMS device that finds use both as capacitive micromachined ultrasonic transducer (CMUT) and pressure sensor. The MEMS device is first designed and simulated to work as a CMUT operating at about 5 MHz frequency. The device can also function as a ...