Aqui você encontrará apresentações realizadas nas Conferências de Usuários COMSOL de todo o mundo. As apresentações englobam pesquisas e produtos inovadores feitas por engenheiros e cientistas usando o COMSOL Multiphysics. Os tópicos abrangem uma grande gama de indústrias e aplicações, como elétrica, mecânica, escoamento e química. Use a função de busca "Quick Search" para encontrar apresentações na sua área de interesse.

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 ...

CMUT Based Free Membrane Intra-Cardiac Volumetric Blood Flow-Meter

P. Priya [1], B. D. Pant [2],
[1] Birla Institute of Technology and Science Pilani, Pilani, Rajasthan, India
[2] CSIR-Central Electronics Engineering Research Institute, Pilani, Rajasthan, India

In this paper, a free membrane is used as a receiver to increase the capacitance and therefore the resolution of the flow meter. For the current application, from the wavelength of sound wave in soft tissue (c= 1540 m/s) the resolution was calculated to be 0.48 mm. This gives the first Eigen frequency of the capacitive structure according to which the poly silicon membrane was designed. After ...

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, ...

SAW Sensors for Surgical Arm using Piezoelectric Devices

Rakesh Kumar Pati [1], SK Mohammed ali[1], Sakuntala Mahapatra[1], Millee Panigrahi[1]
[1]MEMS Design Centre, Dept. of ETC, Trident Academy of Technology, Bhubaneswar, Odisha, India

Despite of the existing successful clinical applications, however, the interaction, i.e. artificial sensing, between the robot and the patient is still very limited. With the help of various cameras, vision is almost the only feeling that a robot can have. In order to imitate the human skin, various signals e.g., the strength of pressure, change of strength, speed and acceleration should be ...

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 ...

Acoustic Wave Crack Detection: A First Principles Approach

R. W. Pryor [1],
[1] Pryor Knowledge Systems, Inc., Bloomfield Hills, MI, USA

Crack detection is and has been an active field of exploration, both theoretical and applied for a number of years. It is the belief of this author that the concepts presented herein explore a new methodology for the modeling and the detection of cracks and families of cracks in crystalline solids, polycrystalline solids and high viscosity amorphous materials (glasses). In the case of the ...

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 ...

COMSOL Analysis of Acoustic Streaming and Microparticle Acoustophoresis

H. Bruus[1], P.B. Muller[1], R. Barnkob[1], M.J.H. Jensen[2]
[1]Technical University of Denmark, Kongens Lyngby, Denmark
[2]COMSOL, Kongens Lyngby, Denmark

We have simulated the ultrasound-induced acoustophoretic motion of microparticles suspended in an aqueous solution. The full first-order thermoviscous acoustics equations have been implented on a rectangular microfluidic 2D domain excited with an ultrasound field tuned to resonance near 2 MHz. The micrometer-thin but crucial viscous boundary layers at the rigid walls have been fully resolved. ...

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; ...