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.

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 ...

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 ...

Effects of Fluid and Structural Forces on the Dynamic Performance of High Speed Rotating Impellers.

C. Thiagarajan[1], G. Shenoy[2], B. S. Shenoy[3]
[1]ATOA Scientific Technologies Pvt Ltd, Whitefield, Bangalore, India.
[2]Department of Mechanical & Manufacturing Engineering, Manipal Institute of technology, Manipal, India
[3]Department of Aeronautical & Automobile Engineering, Manipal Institute of Technology, Manipal, India

Vibration and Dynamic performances of the rotating machinery are conventionally evaluated based on the dominant structural forces such as the centrifugal forces. The increase in rotational speed, miniaturization and performance, demands for improved and accurate evaluation of the vibration performance. The inclusion of coupled effects of fluid and centrifugal forces can contribute significantly ...

Empirical Model Dedicated to the Sensitivity Study of Acoustic Hydrogen Gas Sensors Using COMSOL Multiphysics®

A. Ndieguene[1], I. Kerroum[1], F. Domingue[1], A. Reinhardt[2]
[1]Laboratoire des Microsystèmes et de Télécommunications/Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
[2]Laboratoire d’Électronique et des Technologies de l’Information, CEA, LETI Grenoble, France

Due to the increasing demand for hydrogen gas sensors for applications such as automation, transportation, or environmental monitoring, the need for sensitive and reliable sensors with a short response time is increasing. This paper presents an empirical model that studies the sensitivity of acoustic hydrogen gas sensors. A parametric study based on the variation of physical properties of ...

Development of a Reactive Silencer for Turbo Compressors

J. Smeulers[1], N. Gonzalez Diez[1]
[1]TNO, Delft, The Netherlands

Turbo compressors can generate high frequency tonal noise, causing nuisance in the environment. As the noise is radiated from the piping, a silencer is installed between the compressor and the pipe system. Commonly an absorption silencer is applied, which is a vessel that contains acoustic absorption material. Due to high flow velocities and vibrations the absorption material may be blown out ...

COMSOL Multiphysics® Software for Simulation of Surface Response to Excitation Method for Manufacturing Process Performance Monitoring - new

H. Fekrmandi[1], N. Miniello[1], R. Kiflemariam[1], I. Nur Tansel[1]
[1]Mechanical & Materials Engineering Department, Florida International University, Miami, FL, USA

In this study, COMSOL Multiphysics® software was used to simulate the surface response to excitation method (SuRE). An aluminum beam with a piezoelectric element bonded is modeled using the COMSOL Acoustics Module. A frequency domain sweep study was performed to simulate the sweep sign generation. The frequency spectrum of the structure is monitored through a frequency range of (20kHz-400kHz). A ...

Sound Field Analysis of Monumental Structures by the Application of Diffusion Equation Model - new

Z. S. Gul[1], N. Xiang[2], M. Caliskan[3]
[1]Department of Architecture, Middle East Technical University, Ankara, Turkey
[2]School of Architecture, Rensselaer Polytechnic Institute, Troy, NY, USA
[3]Department of Mechanical Engineering, Middle East Technical University, Ankara, Turkey

Sound energy distribution patterns within enclosed spaces are the basic concerns of architectural acoustics. Energy decays are analyzed for major acoustical parameter estimations, while spatial energy distribution and flow vectors are indicative in the analysis of sound energy circulation and concentration zones. In this study the acoustical field of a real-size multi-domed monumental ...

Support-Q Optimisation of a Trapped Mode Beam Resonator - new

T. H. Hanley[1], H. T. D. Grigg[1], B. J. Gallacher[1]
[1]Newcastle University, Newcastle-Upon-Tyne, UK

Introducing a disorder into a finite periodic oscillatory system induces the presence of a 'trapped mode': a mode in which the displacement field is localised to the region of the disorder. A main inhibitor to MEMS resonators achieving a high quality (Q) factor is energy radiation through the support to the substrate. The trapped modes present a way to tune this to a minimal value. An initial ...

Analysis of a Plasma-Mediated Photoacoustic Response From Plasmonic Nanoparticles in Ultrashort Regime

A. Hatef [1], B. Darvish [1], A. Dagallier [2], C. Boutopoulos [2], M. Meunier [2],
[1] Nipissing University, North Bay, ON, Canada
[2] École Polytechnique de Montréal, Montréal, QC, Canada

Over the last decade, plasmonic nanoparticles (PNPs) have received growing interest as exogenous contrast agents in the thermal expansion based photoacoustic (PA) imaging technique in biomedical applications [1]. Such functionality is due to the localized surface plasmon resonance (LSPR) created by the light-induced coherent oscillation of the conduction electrons in the PNPs. In the near-field ...

Friction Factor for Perforated Pipes

D. Neihguk [1], M. L. Munjal [2], A. Prasad [1],
[1] Mahindra & Mahindra Ltd, Chennai, India
[2] Indian Institute of Science, Bangalore, India

Perforated pipes are extensively used to control exhaust noise in automobiles [1-4]. The energy loss associated with the perforations leads to back pressure which needs to be quantified and minimized [5]. An objective approach presented in [6] is the introduction of friction factor for perforated ducts as a function of the porosity. In this article, the utilization of the CFD Module of COMSOL ...