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.

Modeling of a Jecklin Disk for Stereophonic Recordings

G. McRobbie[1]
[1]University of the West of Scotland, Paisley, Renfrewshire, UK

The Jecklin Disk is a sound absorbing disk placed between two omnidirectional microphones. It is used to recreate some of the frequency-response, time and amplitude variations human listeners’ experience, but in such a way that the recordings also produce a useable stereo image through loudspeakers. This paper presents a finite element model able to simulate the effects on sound propagation ...

Feed-forward/Feed-backward Mechanical Amplification in the Mouse Cochlea

J. Soons[1,2], C. Steele[2], S. Puria[2]
[1]Lab of Biomedical physics, University of Antwerp, Antwerp, Belgium
[2]Department of Mechanical Engineering, Stanford University, Stanford, USA

Sound vibrations are collected from the external environment by the eardrum and are guided to the basilar membrane in the cochlea. Pressure differences in the two scalae of the cochlea result in a traveling wave on the basilar membrane. The tiny displacements are detected by the deflection of thousands of hair cells, situated along this membrane. It is hypothesized that some 3/4 of these hair ...

A Study of the Effects of Mounting Supports, and Dissipation on a Piezoelectric Quartz Double-Ended Tuning Fork Gyroscope

G. Choi[1], Y. Yong[1]
[1]Rutgers University, New Brunswick, NJ, USA

A COMSOL model of a piezoelectric quartz double ended tuning fork gyroscope was implemented. The gyroscope has two detection modes; the first mode detects the angular velocity about a z-axis perpendicular to the tuning fork plane (x-y plane), while the second mode detects the angular velocity about a y-axis that is the longitudinal axis along the length of the tuning fork. Eigenfrequency ...

An Acoustical Finite Element Model of Perforated Elements

P. Bonfiglio[1][2] and F. Pompoli[1][2]
[1]Materiacustica S.r.l., Ferrara, Italy
[2]Engineering Department, University of Ferrara, Ferrara, Italy

The present work deals with a numerical investigation of resonating systems used for noise control applications. In literature one can find analytical models based on fluiddynamics concepts for evaluating losses occurring across the holes of the perforates. In the paper an acoustical formulation based on the equivalent dissipative fluid approach will be analyzed. It will be firstly applied to ...

Influence of Thermal Conductivity and Plasma Pressure on Temperature Distribution and Acoustical Eigenfrequencies of High-Intensity Discharge Lamps

J. Schwieger[1], B. Baumann[1], M. Wolff[1], F. Manders[2], J. Suijker[2]
[1]Heinrich-Blasius-Institute of Physical Technologies, Hamburg University of Applied Sciences, Hamburg, Germany
[2]Philips Lighting, Turnhout, Belgium

High-intensity discharge (HID) lamps are energy-efficient light sources with excellent color qualities. A three-dimensional model of a low-wattage lamp, which includes plasma, electrodes, and burner walls, was developed in COMSOL Multiphysics®. Most parameters appearing in the coupled differential equations of the model, such as viscosity, thermal and electrical conductivity are temperature ...

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 ...

Cloud Computations for Acoustics with Coupled Physics - new

A. Daneryd[1], D. Ericsson[2]
[1]ABB Corporate Research, Västerås, Sweden
[2]COMSOL AB, Stockholm, Sweden

For certain classes of scientific and technical computations the cloud may offer easily accessible, scalable, and affordable gigantic computing power. A power that for these classes may lead to a step change in model and analysis complexity compared to what is feasible with dedicated clusters and similar networked solutions. Acoustics with or without interaction with coupled physics fields ...

Simulation of SAW-Driven Microparticle Acoustophoresis Using COMSOL Multiphysics® Software

N. Nama [1], R. Barnkob [2], C. J. Kähler [2], T. J. Huang [1], F. Costanzo [1]
[1] Department of Engineering Science and Mechanics, Pennsylvania State University, PA, USA
[2] Institute of Fluid Mechanics and Aerodynamics, Bundeswehr University Munich, Neubiberg, Germany

Introduction - The ability to precisely manipulate fluid and particles at microscales is one of the essential requirements for various lab-on-a-chip applications such as drug diagnostics, chemical synthesis etc.[1] Recently, the nonlinear interaction of surface acoustic waves (SAW) with fluid at microscales has been utilized to achieve this aim. When surface acoustic waves interact with fluid ...

On the Numerical Modeling of Elastic Resonant Acoustic Scatterers

V. Romero-García[1], A. Krynkin[2], J.V. Sánchez-Pérez[1], S. Castiñeira-Ibáñez[3], and L.M. Garcia-Raffi[4]
[1]Centro de Tecnologías Físicas Acústica, Universidad Politécnica de Valencia, Valencia, Spain
[2]School of Computing, Science & Engineering, University of Salford, Salford, United Kingdom
[3]Depto. Física Aplicada, Universidad Politécnica de Valencia, Valencia, Spain
[4]Instituto Universitario de Matemática Pura y Aplicada, Universidad Politécnica de Valencia, Valencia, Spain

The elastic and geometrical properties of Low Density Polyethylene (LDPE) foam are used in this paper to improve the attenuation properties of periodic arrangements of acoustic scatterers known as Sonic Crystals (SCs). A specific recycled profile of LDPE foam is used as elastic-acoustic scatterer. The acoustic spectrum of the single scatterer shows two attenuation peaks in the low frequency ...

Calibration of Ultrasonic Testing for Faults Detection in Stone Masonry

M. Usai[1], S. Carcangiu[1], G. Concu[2]
[1]Department of Electrical and Electronic Engineering, University of Cagliari, Cagliari, Italy
[2]Department of Civil Engineering, Environmental and Architecture, University of Cagliari, Cagliari, Italy

In the field of assessment methodologies, particular importance is given to Non-Destructive Testing Techniques, which aspire to achieve the highest number of information about materials and structures without altering their condition. Ultrasonic Testing exploits the transmission and reflection characteristics of mechanical waves with appropriate frequencies passing through the investigated item. ...