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.

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 ...

FEM Simulation for ‘Pulse-Echo’ Performances of an Ultrasound Imaging Linear Probe

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

Pulse-echo FEM simulation is seldom found in literature for ultrasound imaging array probes, since the complete modeling of such device is extremely complicated. Nevertheless, the 2D FEM described in the present work was successful, thanks to the following design procedure (see figure): Two piezoacoustic models were employed, one for transmission of the pressure wave into the acoustic domain, ...

Modeling the Sound Radiation by Loudspeaker Cabinets - new

M. Cobianchi[1], M. Rousseau[1]
[1] B&W Group Ltd, Steyning, UK

While musical instruments often rely on a body which resonates on purposefully to amplify the vibration produced by a string or a membrane, such as in a violin or a guitar, loudspeaker cabinets should not contribute at all to the total sound radiation, but aim instead to be a perfectly rigid box which encloses the drive units in charge to transform the electrical signal at their terminal into ...

Acoustical Design of Stethoscope for Improved Performance

C. Thiagarajan[1], Gururajan R.[2], A. H. Baig[2], Prema S.[3]
[1]ATOA Scientific Technologies Pvt Ltd, Whitefield, Bangalore, Karnataka India
[2]University of Southern Queensland, Toowoomba Qld 4350, Australia.
[3]RMK Engineering College, Chennai, Tamil Nadu, India

Stethoscope is in use for more than 200 years for medical diagnostics, especially for auscultation. Recently, the unprecedented growth in mobile technology revived the use of stethoscope for Telehealthcare. Digital or electronic stethoscopes are increasingly researched for use in Telehealthcare. This paper mainly focuses on the acoustical and multiphysics design aspects of the stethoscope for ...

Acoustic Wave Propagation in Water Filled Buried Polyethylene Pipes - new

T. Graf[1], T. Gisler[1], P. Sollberger[1], O. Schaelli[1]
[1]School of Engineering and Architecture, Lucerne University, Horw, Switzerland

Axisymmetric acoustic waves propagating along buried water pipes have been investigated by FEM and experimentally. Universal dispersion relations of the fundamental mode were obtained as a function of the standard dimension ratio SDR and of the material surrounding the pipe (soil, air). At low frequency there exists little dispersion and the “dc” phase velocity of the leak noise is independent ...

MEMS Electrostatic Acoustic Pixel

A. Arevalo [1], D. Conchouso [1], D. Castro [1], I. G. Foulds [2],
[1] Computer, Electrical, & Mathematical Sciences & Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
[2] The University of British Columbia, School of Engineering, Vancouver, BC, Canada

The growth of the electronics industry demand better components for the electronic systems. Such components need to be improve to keep up with the evolution of the digital era. The loudspeaker design has not been changed for almost a century [1-5]. The acoustic transducer is the last analogue component needed for a true digital audio system. We want to validate the feasibility of using an ...

Accuracy of Fully Coupled Loudspeaker Simulation Using COMSOL

M. Hedges[1][2] and Y.W. Lam[1]
[1]Acoustics Research Centre, School of Computing, Science & Engineering, University of Salford, Salford, United Kingdom
[2]Monitor Audio Ltd., Rayleigh, Essex, United Kingdom

Loudspeaker simulation is used to inform the designer as to the performance of a design. In recent years the Finite Element Method (FEM) has been used to model the mechanical and acoustical attributes of a loudspeaker with varying success. This paper shows how a model that incorporates the magnetic, electromagnetic, mechanical and acoustical domains performs. These domains will be coupled where ...

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 ...

A Multiphysics Approach to the Design of Loudspeaker Drivers

R. Magalotti [1]
[1] B&C Speakers, Bagno a Ripoli, Italy

Loudspeaker drivers are energy transducers: their main goal is to efficiently convert electrical energy to acoustic energy (sound), through the movement of mechanical parts. As such, they are prime candidates for the application of multiphysics methods and tools. The talk will outline the growing set of tools that COMSOL Multiphysics® software puts in the hands of the loudspeaker designer; ...

Research on a Numerical Simulation Method about Harmonic Distortion of Loudspeaker - new

X. Lu[1]
[1]Zhejiang Electro-Acoustic R&D Center, CAS, Zhejiang, China

扬声器的失真问题一直受电声业界的关注,尤其是谐波失真,它是影响扬声器重放声音音质的主要因素之一。 本文提出了一种基于 COMSOL Multiphysics® 软件预测扬声器谐波失真的仿真分析方法。该方法需建立包括磁场、振动系统和声场等多个物理场的扬声器的全模型,给扬声器加载一单频电压信号,用瞬态分析的方法可求解得到该频率激励下的扬声器的多个重要物理量随时间的变化函数,如流经音圈的电流I(t)、音圈的受力F(t)、振动系统表面上任意点的位移x(t),以及声场中任意点的声压P(t)等。给扬声器加载一个时间长度为0.1s的单频电压信号,仿真分析所得的防尘帽顶点的位移曲线 x(t) 如图1所示,图2则是对应的在扬声器正前方0.1m处的声压曲线 P(t)。 再对所得的声压信号的稳态部分做FFT频谱分析,便可获得输入信号的各阶次谐波分量 ...