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.

Dynamic Characterization and Mechanical Simulation of Cantilevers for Electromechanical Vibration Energy Harvesting

N. Alcheick[1], H. Nesser[1], H. Debeda[1], C. Ayela[1], I. Dufour [1]
[1]Univ. Bordeaux, IMS Lab, Pessac, France

Energy harvesting from ambient vibrations has become an interesting topic for powering wireless sensor networks. Resonant microdevices based on MEMS have become of central importance at low frequency. The power produced at resonance is at least one order of magnitude larger than off frequency power since the largest strain is obtained at resonance. In order to obtain large strain for efficient ...

Modeling and Experimental Verification of the Power Transfer and Thermal Characteristics of Piezoelectric Transformers Subjected to Combined Mechanical and Electrical Loading

S. Tuncdemir[1], W.M. Bradley[2]
[1]Solid State Ceramics, Williamsport, PA, USA
[2]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 ...

Analysis of High-Frequency Thermoacoustic Instabilities in Lean, Premixed Gas Turbine Combustors

F. Berger [1], T. Hummel [1], P. Romero [1], M. Schulze [1], B. Schuermans [2], T. Sattelmayer [1],
[1] Lehrstuhl für Thermodynamik, TU München, Germany
[2] 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 ...

Numerical Simulation of Phonon Dispersion Relations for Phononic Crystals

G. Zhu[1], E.M. Dede[1]
[1]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 [1]. 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 ...

Time-Dependent Study of Pressure Waves Generated by Square Array MEMS Ultrasound Transducers

M. A. G. Suijlen [1], R. J. Woltjer [1],
[1] 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 ...

Phonon Tunneling Loss Solver for Micro- and Nanomechanical Resonators

G.D. Cole[1], M. Aspelmeyer[1], and I. Wilson-Rae[2]
[1]University of Vienna, Vienna, Austria
[2]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 ...

Optimization of Acoustic Silencer for the Screw Compressor System - new

M. Swamy[1], L. J. van Lier[1], J. Smeulers[1]
[1]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 ...

Simulação de um Sistema de Levitação Acústica para Manipulação de Partículas em Ar

M. A. B. Andrade [1], N. Pérez [2], J. C. Adamowski [3],
[1] Instituto de Física, Universidade de São Paulo, São Paulo, SP, Brasil
[2] Centro Universitario de Paysandú, Universidad de la República, Paysandú, Uruguai
[3] 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 ...

Virtual Commissioning of Large Machines with COMSOL Multiphysics® Software

K. Kryniski [1], A. Trangard [1],
[1] 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 ...

Compression Driver Simulation Including Air Damping in Phase Plug

R.Christensen, and U. Skov
iCapture ApS
Gadstrup, Denmark

A compression driver is a certain type of electrodynamic loudspeaker which has a phase plug with slits in front of the diaphragm. The slits are narrow enough that the so-called viscothermal effects are of significant importance. In this paper a 2D axisymmetric finite element model of a commercial compression driver is established where the vibroacoustic behavior can be evaluated. The ...