In questa sezione troverete i lavori presentati alle Conferenze mondiali COMSOL. Le presentazioni descrivono ricerche e prodotti innovativi progettati con COMSOL Multiphysics da colleghi di tutto il mondo. I temi delle ricerche presentate abbracciano un'ampia gamma di settori produttivi e aree applicative, in ambito elettrico, meccanico, fluidodinamico e chimico. Lo strumento di Ricerca Rapida vi permetterà di trovare le presentazioni che si riferiscono all'area di vostro interesse.

Piezoelectric Buzzer Optimization for Micropumps

A. Garcia[1], A. Marcus[1], F. Tejo[1], C. Precker[1], C. Moreira[2]
[1]Universidade Federal de Campina Grande, Campina Grande, PB, Brazil
[2]Instituto Federal de Alagoas, Maceio, AL, Brazil

Piezoelectric buzzers are low cost devices which can be used successfully as actuators in diaphragm-based micro-pumps. The buzzers are piezoelectric wafers (lead-zirconate-titanate-PZT) that are glued on a brass membrane and they are available within different sizes and thicknesses. For the best performance of a diaphragm pump, it is necessary to have a large displacement of the membrane. This ...

Orientation of Piezoelectric Crystals and Acoustic Wave Propagation

G. Zhang[1]
[1]Clemson University, Clemson, SC, USA

Surface acoustic wave (SAW) devices are commonly used as wireless filters, resonators, and sensors. The confinement of acoustic energy near the surface of a piezoelectric substrate in a SAW sensor makes it highly sensitive for discerning surface perturbation. As sensors, SAW devices have the potential to provide a high-performance sensing platform with capabilities of remote and high-temperature ...

Modeling of Pinna Related Transfer Functions (PRTF) Using the Finite Element Method (FEM)

M. Joshi[1], N. Gupta[1], L. Hmurcik[1]
[1]University of Bridgeport, Bridgeport, CT, USA

Pinna Related Transfer Functions (PRTFs) are signal processing models that represent the modifications undergone by the acoustic signal as it interacts with the listener’s pinna (outer ear). PRTFs are used to generate binaural sounds, especially those coming from an elevation. The complex shape of the pinna causes reflections, diffractions and resonances that give rise to a unique PRTF for each ...

Surface Acoustic Wave Scattering Matrix Evaluation Using COMSOL Multiphysics®: Application to Surface Acoustic Wave Transmission Through 2D Surface Phononic Crystal

S. Yankin[1,2], A. Talbi[1], V. Preobrazhensky[1,3], P. Pernod[1], O. Bou Matar[1], A. Pavlova[1]
[1] Joint International Laboratory LICS/LEMAC, IEMN UMR CNRS 8520, EC Lille, Villeneuve d'Ascq, France
[2] Saratov State University, Saratov, Russia
[3] Wave Research Center, Russian Academy of Sciences, Moscow, Russia

This contribution is dedicated to numerical analysis of SAW propagation though 2D surface phononic crystal (PnC) and FE method is nowadays one of most common tool for such calculation. The device under investigation consists of two dispersive IDT and lattice of ferromagnetic pillars realized on 128°YX LiNbO3. In addition to dispersion curves calculations this work describes the results of ...

Analysis of an Air Transparent Soundproof Window System & Comparisons to Physical Test Data - new

M. Yeoman[1], V. Sivasailam[1], A. Tomar[2]
[1]Continuum Blue Ltd., Ystrad Mynach, UK
[2]Jaguar Land Rover Ltd, Coventry, UK

The design of windows and or other perforated structures which allow the free flow of air into & out of a building or system, while being fully soundproofed or attenuate certain frequencies is of great interest to architects and design engineers, where sound as a longitudinal wave, is difficult to separate it from its medium of propagation. In this work, we present the analysis of air ...

Study & Modeling of 'Acoustic Matching Layers' for Ultrasound Imaging Probes Through Pulse-Echo FEM Simulation - new

L. Spicci[1]
[1]Esaote SpA, Florence, Italy

Ultrasound Imaging probes are specific devices that require a very detailed design of acoustic impedance match for the stack of layers that form the probe head (1,3). These are typically made of silicone rubber, special epoxy resins, polyurethanes and, of course, piezoelectric materials. The acoustic impedance, measured in Rayls, have to be matched similarly to an electric circuit (2), from a ...

Finite Element Model for Simulating the Inspection of Steel Tubes Using Electromagnetic Acoustic Transducers - new

P. Sun[1], X. Ding[1], X. Wu[1], M. Cong[1]
[1]School of Mechanical Science & Engineering, Huazhong University of Science and Technology, Wuhan, China

Steel tubes are widely used in industries. In order to ensure the safety and reliability of industrial processes, electromagnetic acoustic transducers (EMATs) based guided wave technology has been developed for inspecting stainless steel tubes regularly. Theoretical models and finite element modes have been built to investigate the EMAT technology. However, existing models mainly focused on ...

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 ...

PVDF Piezoelectric Nanofibers as Hair Cell Substitutes: A Feasibility Study

C. R. Pérez [1], J. J. Santiago-Avilés [2],
[1] Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, USA
[2] Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, USA

Sensorineural hearing loss is the most common sensory deficit in the world, and within this category damage or loss of the primary sensory cells of the inner ear, known as hair cells is the most common cause [1]. Partial hearing loss is addressed by the use of hearing aids, electronic devices that greatly amplify sound directly into the user's ear, but for more severe cases cochlear implants are ...

The Acoustoelastic Effect: EMAT Excitation and Reception of Lamb Waves in Pre-Stressed Metal Sheets

R.M.G. Ferrari[1]
[1]Danieli Automation S.p.A., Buttrio, UD, Italy

The acoustoelastic effect relates the change in the speed of an acoustic wave travelling in a solid, to the pre-stress of the propagation medium. In this work the possibility of assessing nondestructively the stress status in metal sheets, by using the acoustoelastic effect, is investigated. As the effect turns out to be very small for practical values of applied stress, the proposed technique ...