Here you will find presentations given at COMSOL Conferences around the globe. The presentations explore the innovative research and products designed by your peers using COMSOL Multiphysics. Research topics span a wide array of industries and application areas, including the electrical, mechanical, fluid, and chemical disciplines. Use the Quick Search to find presentations pertaining to your application area.

Simulation of Acoustic Energy Harvesting Using Piezoelectric Plates in a Quarter-Wavelength Straight-Tube Resonator

B. Li[1], J.H. You[1]
[1]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 ...

Bloch Waves in an Infinite, Periodically-perforated Sheet

W. Maysenhölder[1]
[1]Fraunhofer Institute for Building Physics, Stuttgart, Germany

Bloch waves in infinite periodic structures – much in vogue in the present metamaterial age – can be conveniently studied by COMSOL Multiphysics® software. This is demonstrated by a simple, yet rich two-dimensional example: a perforated sheet with square symmetry. Instead of plane waves in homogeneous media, one has to deal with their generalizations: the Bloch waves. The frequencies of such ...

Calculation of Surface Acoustic Waves on a Piezoelectric Substrate using Amazon™ Cloud Computing

U. Vogel [1], M. Spindler [1], S. Wege [1], T. Gemming [1]
[1] Leibniz Institute for Solid State and Materials, Dresden, Germany

In this work, we seek to simulate SAWs for a better understanding and to benchmark the currently available cloud computing possibilities of COMSOL Multiphysics® software. By using the MEMS module we demonstrate 3D models with reduced geometry to achieve principle information about the wavefield. For a benchmark, a high-speed workstation with limited memory (RAM) is compared to the most potent ...

Prediction of the Loudspeaker Total Harmonics Distortion Using COMSOL Multiphysics® Software

F. Malbos [1], M. Bogdanski [2], M. Strauss [2],
[1] Harman, Paris, France
[2] Harman Becker Automotive Systems, Straubing, Germany

For automotive applications, simulation methods are used to get the best audio acoustic performance. Because a loudspeaker is a non linear device, the sound pressure in the vehicle includes harmonics which are mainly created by the force factor, suspension stiffness and voice coil inductance of the loudspeaker. This paper shows how to simulate those non linear components using COMSOL ...

An Improved Loudspeaker Frequency Response by Using a Structure of Rigid Absorptive Panel in a Vented Cabinet - new

R. Balistreri[1]
[1]Community Light & Sound Inc., Chester, PA, USA

When placing a loudspeaker in a cabinet, standing waves inside the cabinet affect the frequency response with ripples. This peaks and dips due to pressure cancellation inside the cabinet have an effect on the diaphragm and generating sound out from the vents. If it was in a condition of total absorption of the sound waves at the back of the diaphragm, the transducer would otherwise have a much ...

Modeling Acoustic Interface Wave Dispersion Using COMSOL Multiphysics®

B. Goldsberry[1], M. Isakson[1]
[1]Applied Research Laboratories, The University of Texas at Austin, Austin, TX, USA

Measuring geoacoustic parameters of underwater sediments is important for accurate modeling of underwater acoustic propagation. While the density and compressional wave speeds can be directly measured in sediments, shear wave speeds are difficult to measure because they are highly attenuated. However, shear wave speeds can be indirectly determined through measurement of Scholte interface wave ...

Laser-Ultrasonics Wave Generation and Propagation FE Model in Metallic Materials

A. Cavuto[1], G.M. Revel [1], M. Martarelli [2], F. Sopranzetti [2]
[1]Università Politecnica delle Marche, Ancona, Italy
[2]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 ...

Simulation of Impact Damage in a Composite Plate and Its Detection

V. Pavelko[1], I. Pavelko[1], M. Smolyaninovs[1], H. Pffeifer[2], M. Wevers[2]
[1]Riga Technical University, Riga, Latvia
[2]Catholic University Leuven, Leuven, Belgium

A problem of damage prediction in aircraft structure and its non-destructive evaluation is very important for aircraft structural health assessment. The analysis of the features of direct impact of thin-walled laminate component of aircraft was performed by COMSOL Multiphysics software. Mainly the GFRC and CFRC laminates were selected in form either thin separate plate or sandwich structure. The ...

Acoustic Field Comparison of High Intensity Focused Ultrasound Using Experimental Characterization and Finite Element Simulation

J. L. Teja[1], A. Vera[1], L. Leija[1]
[1]Department of Electrical Engineering, Cinvestav-IPN, Mexico D.F., Mexico

High Intensity Focused Ultrasound (HIFU) is used as a noninvasive technique of tissue heating and ablation for different medical treatments. This paper presents a quantitative comparison of HIFU acoustic fields experimentally obtained versus simulated acoustic fields. Acoustic field characterization was realized in two HIFU transducers using water as a propagation medium. Also, simulations were ...

Dynamics of Rotors on Hydrodynamic Bearings

R. Eling[1]
[1]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 ...