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 abramgem 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.

Mathematical Model for Prediction of Transmission Loss for Clay Brick Walls

J. Ratnieks[1], A. Jakovics[1], J. Klavins[1]
[1]Laboratory for Modeling Technological and Environmental Processes, University of Latvia, Riga, Latvia

A 2D numerical model for determination of sound reduction index is set up in this work. Results are in good agreement in middle and high frequency range when using solid structure approximation. Results are compared with experiment.

浅海声场建模预报

刘佳琪 [1], 朴胜春 [2], 唐骏 [2]
[1] 哈尔滨工程大学,哈尔滨,黑龙江,中国
[2] 挪威科技大学,特隆赫姆,挪威

海洋覆盖了地球表面百分之七十以上的面积,其中蕴藏着丰富的生物矿产资源,日益受到世界各国的重视。声波作为海水中传输信号的唯一载体,在浅海波导中的传播受海底和海面影响很大,当声波在浅海波导中发生折射反射和散射时,如何预报复杂海底边界条件下浅海中的传播特性对海洋开发有重要意义。针对含有声速剖面的沉积层海底、楔形海底及实际弹性海底,利用有限元理论,对二维浅海声场的传播损失进行数值模拟。应用 COMSOL Multiphysics® 软件的声压接口和声结构耦合接口,把地形数据导入软件模拟真实海底的地形。把浅海波导简化成分层矩形,信号源以点声源的形式向外发射单频信号,在模型定义处添加完美匹配层模拟无限远距离处声压场情况;对于含有声速剖面情况的波导问题,在 COMSOL 中可以较为便捷地以添加内插函数的形式进行仿真,与其他声场建模软件形成对比,突显有限理论元理论计算浅海传播损失的优势 ...

Computational Modeling of Wave Propagation in a Geophysical Domain

J. McKenna[1], M. McKenna[1], S. Yushanov[2], J. Crompton[2], and K. Koppenhoefer[2]
[1]U.S. Army Engineering Research and Development Center
[2]ACES of Columbus, LLC, Columbus, OH, USA

The propagation of shear (S) and compression (P) waves within the earth allows geologists to track seismic events and to identify subterranean structure. This work shows the strong effect of including the variation of wave speed through the top thirty meters of the earth. By including this variation in material properties, the wave arrival time and frequency content agree with experimental data. ...

Sound Propagation through Circular Ducts with Spiral Element Inside

W. Lapka
Poznan University of Technology, Poland

This paper examines a sound propagation without airflow through circular ducts with spiral element inside. Models are numerically computed in three-dimensions. The spiral element in the duct is a newly analyzed acoustical element, geometrically similar to the well-known Archimedes screw. It can be applied significantly in ducted systems, such as ventilation, air-conditioning and heat ...

Modelling the Wall Vibrations of Brass Wind Instruments

V. Chatziioannou, and W. Kausel
Institute of Music Acoustics
University of Music and Performing Arts
Vienna, Austria

The vibration of the walls of brass wind instruments has been a subject of study in the field of musical acoustics throughout the last decades. The amplitude of such vibrations, stimulated by the oscillating air pressure inside the instrument bore, is very small compared to the dimensions of the instrument. However, it has been recently shown that at the flaring regions of the bell of brass ...

High-Intensity Piezo-Ceramic Ultrasonic Transducer with Mechanical Amplifier and Radiation Plate

A. van Wijhe[1], W. de Jong[1]
[1]Process & Energy, 3mE, TU Delft, The Netherlands

A COMSOL Multiphysics® model was made to design a mechanical amplifier and radiation plate for the emission of high intensity 40.5 kHz ultrasound to air by means of a Langevin type transducer usually applied in cleaning baths for example. In this work, ultrasonic irradiation is aimed at acting on flue gas containing fine particulate matter to realize a shift to higher effective particle sizes as ...

From Music to Non-Invasive Therapies via COMSOL Multiphysics® Models - new

E. Lacatus[1], G. C. Alecu[2], A. Tudor[2], M. A. Sopronyi[3]
[1]Polytechnic University of Bucharest, Bucharest, Romania
[2]Student-Polytechnic University of Bucharest, Bucharest, Romania
[3]INFLPR -National Institute for Laser Plasma and Radiation Physics, Bucharest, Romania

Vibration and music therapies are non-invasive treatments having effective results although their basics are still disputed. By the application of COMSOL Multiphysics® software for modeling and analysis, some of the nonlinear physical phenomena laying on these applications may be clarified. Acoustic environmental stimuli at different intensities are continuously interacting with our bodies, ...

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 ...

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 ...

An Investigation of Loudspeaker Simulation Efficiency and Accuracy Using i) A Conventional Model, ii) The Near-To-Far-Field Transformation and iii) The Rayleigh Integral

R. Christensen[1], U. Skov[1]
[1] iCapture ApS, Roskilde, Denmark

Simulation on loudspeaker drivers require a conventional fully coupled vibro-acoustic model to capture all effect. An accurate vibroacoustic model can be time-consuming to solve, especially in 3D. In practical applications, this results in poor efficiency concerning the decision-making process to move on to the next simulation model. To overcome this the loudspeaker designer can use either the ...