Here you will find presentations given at COMSOL Conferences around the globe. The presentations explore the innovative research and products designed by your peers using COMSOL Multiphysics. Research topics span a wide array of industries and application areas, including the electrical, mechanical, fluid, and chemical disciplines. Use the Quick Search to find presentations pertaining to your application area.

Modeling Acoustic Waveguides for Ear Impedance Measurements

R. Sisto[1], L. Cerini[1], D. Mambro[2], A. Moleti[2], F. Sanjust[1]
[1]INAIL Research, Monteporzio Catone, Italy
[2]Università di Roma, Tor Vergata, Italy

The otoacoustic emissions (OAEs) are acoustic signals emitted by the inner ear as a consequence of the activity of a nonlinear feedback mechanism capable of amplifying the signal near to the hearing threshold level. The otoacoustic emissions can be used as an acoustic imaging of the cochlear functionality. They are used in clinics for screening purposes but due to the extreme variability ...

A Lesson in Cartilage Therapy: Do Chondrocytes Utilize Mechanical Energy from Exercise for Cell Maintenance and Growth?

A. Miller [1], H. Viljoen [1], A. Chama [2], T. Louw [2],
[1] Department of Chemical and Biomolecular Engineering, University of Nebraska - Lincoln, Lincoln, NE, USA
[2] Department of Chemical Engineering, Stellenbosch University, Stellenbosch, South Africa

- Using COMSOL Multiphysics® Acoustics Module: Chondrocytes modeled attached to a plane (to mimic in vivo constraints) are shown to resonate near 5MHz. At resonance, the mechanical energy density in the nucleus is two times higher than in the cytoplasm. - Impact exercise is modeled as traveling pressure pulses and shown to cause cells to vibrate primarily at the resonance frequency. - Two ...

A Study of the Acoustic Response of Carbon Fiber Reinforced Plastic Plates

J. O'Donnell, and G. McRobbie
University of the West of Scotland
Paisly, United Kingdom

This paper gives an introduction to a continuing study detailing the process and development of using both experimental and Finite Element Analysis to characterise the acoustic response of a Carbon Fiber Reinforced Plastic (CFRP) laminate plate provided by a guitar manufacturer. The results show that there is a strong correlation between both the experimental and simulated data which gives ...

基频最大的经纬仪基座的拓扑优化

高阁 [1][2], 刘震宇 [1],
[1] 中国科学院长春光学精密机械与物理研究所,长春,吉林,中国
[2] 中国科学院大学,北京,中国

In order to satisfy the requirements of modern range measuring technology, photoelectric theodolites gradually develop towards lightweight and minitype design. As a consequence, the mobile theodolite is becoming a hot spot recently. New requirements are raised for the theodolite base (Figure1), which is an essential part of photoelectric theodolites. Namely, the eigenfrequencies should be high ...

Temperature Gradients Controlled Broadband Acoustic Omnidirectional Absorber - new

F. Qian[1], L. Quan[1], X. Liu[1]
[1]Institute of Acoustics and School of Physics, Nanjing University, Nanjing, China

Previous research into acoustic omnidirectional absorber (AOA) has shown the feasibility of forming acoustic black hole to guide the incident wave into the central absorptive cavity. However, major restrictions to practical applications exist due to complexity of designing metamaterials and unchangeable working states. Here, we propose two cylindrical, two-dimensional AOA schemes based on ...

Transient Vacuum and High Pressure Generation by Focused Acoustic Waves

R. Eisenschmid [1],
[1] OPTIMA pharma GmbH, Schwaebisch Hall, Germany

Amplitude of acoustic waves can be magnified by conical or concave waveguides, like in ear trumpets or fjords (surface waves). The simplest way realizing a capable device is a conical waveguide with a target to be treated in the top of the cone, and a spherical actor or acoustic exciter on the other end. The acoustic amplitude is magnified, respectively compressed by the ratio of the local cross ...

Simulation Analysis of Acoustic Radiation Force under Ultrasound Exposure and Effect to Microbubbles in Flow

T. Ito
Masuda Laboratory
Tokyo University of Agriculture & Technology
Japan

This paper is in Japanese.

Earth Pressure as a Boundary Condition to Bridge Piers and Abutments

M. Quinn[1], D. Whitlow[1], O.D.S. Taylor[1], M.H. McKenna[1]
[1] Engineer Resource and Development Center, United States Army Corps of Engineers, Vicksburg, MS, USA

Bridge piers and abutments makeup the bridge substructure and transmit loads from the superstructure to the bridge foundation material (Figure 1). The bridge abutment serves three purposes: to provide vertical support to the bridge superstructure where the bridge ends, to connect the bridge with the approach roadway, and to retain roadway base materials. There are several types of abutment ...

基于 COMSOL 的 e-SHM 系统齿轮的负压波损伤监测

王佳琪 [1],
[1] 上海交通大学,上海,中国

将结构健康监测(SHM)应用于机器结构故障检测是近些年发展的新方法,其优点是可以在线监控结构的“健康”状况。本文提出并研究了一种内嵌微管的高效结构健康监测(e-SHM)系统。结合快速成型技术,将微管嵌入结构内部,当对微管施加一定压力(真空或过压)时,闭合微管中的压力变化将变得极其敏感。当结构裂纹扩展到微管时,该处因压差瞬间产生压力变化,进而通过微管传播,最终信号被设置的压力传感器接收。通过实时监测微管的压力变化,便可实现结构裂纹的实时检测。本文的主要工作包括两个方面:(1)压力泄漏与负压波传播模型的设计与仿真。基于负压波的 e-SHM 系统齿轮的损伤监测的理论推导,包括负压波的产生原理和负压波在微管中的传播过程。建立了直管泄漏的负压波仿真模型,并在 MATLAB 环境下编程实现。基于传感压力二维曲线图分析了仿真结果的识别精度等级,验证了基于负压波的 e-SHM 系统的损伤监测的可行性。 ...

Simulation and Evaluation of Small High-Frequency Side Scan Sonars Using COMSOL

J. Jonsson[1], E. Edqvist[1], H. Kratz[1], M. Almqvist[2], and G. Thornell[1]
[1]Ångström Space Technology Centre, Uppsala University, Uppsala, Sweden
[2]Department of Measurement Technology and Industrial Electrical Engineering, Lund University, Lund, Sweden

High frequency side-scan sonar, to be fitted on a miniaturized submersible explorer, have been simulated and built. The purpose of this study is to see if COMSOL Multiphysics® can be used to predict the performance of the sonar, especially the beam width, setting the resolution of the system. Four models were created, from simple 2-D geometries to more complex 3-D models. The simulated beam ...