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.

Increasing Heat Transfer in Microchannels with Surface Acoustic Waves - new

S. Berry[1]
[1]Massachusetts Institute of Technology: Lincoln Laboratory, Lexington, MA, USA

In this numerical study, surface acoustic waves (SAWs) are evaluated as a potential disruptive flow technology for enhancing heat transfer in microchannels. Using COMSOL Multiphysics® software, the physics governing acoustics, single-phase-fluid flow and heat transfer are coupled. The results show that acoustic streaming can disrupt the bulk fluid flow, creating rotating vortices within the ...

PVDF Piezoelectric Nanofibers as Hair Cell Substitutes: A Feasibility Study

C. R. Pérez [1], J. J. Santiago-Avilés [2],
[1] Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, USA
[2] Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, USA

Sensorineural hearing loss is the most common sensory deficit in the world, and within this category damage or loss of the primary sensory cells of the inner ear, known as hair cells is the most common cause [1]. Partial hearing loss is addressed by the use of hearing aids, electronic devices that greatly amplify sound directly into the user's ear, but for more severe cases cochlear implants are ...

The Acoustoelastic Effect: EMAT Excitation and Reception of Lamb Waves in Pre-Stressed Metal Sheets

R.M.G. Ferrari[1]
[1]Danieli Automation S.p.A., Buttrio, UD, Italy

The acoustoelastic effect relates the change in the speed of an acoustic wave travelling in a solid, to the pre-stress of the propagation medium. In this work the possibility of assessing nondestructively the stress status in metal sheets, by using the acoustoelastic effect, is investigated. As the effect turns out to be very small for practical values of applied stress, the proposed technique ...

Design Of Acoustic Metamaterials Based On The Concept Of Dual Transmission Line

A-S.Moreau[1], H.Lissek[1], and F. Bongard[2]
[1]Ecole Polytechnique Fédérale de Lausanne, Switzerland
[2]JAST SA, Antenna Systems, Lausanne, Switzerland

In this context, a one-dimensional acoustic transmission line, exhibiting metamaterial properties, is presented. It is composed of an acoustic waveguide, periodically loaded with membranes having the function of series capacitances, as well as transversally connected open channels (denoted stubs) having the function of shunt inductances. A validation of the transmission line design is made ...

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 ...

基于声学超材料的菲涅尔声透镜

韩建宁 [1], 罗世通 [1],
[1] 中北大学,太原,中国

基于声学透镜的声学聚焦技术已经在医学检测及医学治疗中有着广泛应用,特别是在 HIFU 技术中有着重要的地位。虽然近几年声学聚焦技术已经有着很多的成果,但是由于“衍射极限”的问题,聚焦区域有一定的限制。声学超材料技术是当前物理领域的热点,该技术的相关成果和优势已经渗透到多个学科的研究中。本文为了更好地抓住学科交叉的技术优势,发挥声学超材料在声学聚焦技术中的优势,使用 COMSOL Multiphysics® 进行了水下聚焦超声技术研究,得到了较好的实验效果。这些研究对推动我国的声学透镜技术研究有较大的帮助,对基于 COMSOL 的有限元分析声学透镜技术有较大的借鉴。

Lumped Element Multimode Modeling of Balanced-armature Receiver with COMSOL Multiphysics® Software

Wei Sun [1],
[1] Institute of Acoustics, Tongji University, China

For the lack of higher order modes, lumped element (LE) models currently used may be insufficient to predict the system of balanced-armature receiver (BAR). We develop a LE multimode model for BAR in the frequency domain based on the techniques of mode decomposition, truncation, and selection via COMSOL Multiphysics® software. The validation is made by comparing with both the corresponding ...

Compression Driver Simulation Including Air Damping in Phase Plug

R.Christensen, and U. Skov
iCapture ApS
Gadstrup, Denmark

A compression driver is a certain type of electrodynamic loudspeaker which has a phase plug with slits in front of the diaphragm. The slits are narrow enough that the so-called viscothermal effects are of significant importance. In this paper a 2D axisymmetric finite element model of a commercial compression driver is established where the vibroacoustic behavior can be evaluated. The ...

Study & Modeling of 'Acoustic Matching Layers' for Ultrasound Imaging Probes Through Pulse-Echo FEM Simulation - new

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

Ultrasound Imaging probes are specific devices that require a very detailed design of acoustic impedance match for the stack of layers that form the probe head (1,3). These are typically made of silicone rubber, special epoxy resins, polyurethanes and, of course, piezoelectric materials. The acoustic impedance, measured in Rayls, have to be matched similarly to an electric circuit (2), from a ...

Numerical Modelling of Wave Propagation in Particulate Composites

P. S. K. Mylavarapu, and S. Boddapati
Defence Metallurgical Research Laboratory

Syntactic foams are hollow particle filled composites that have recently emerged as attractive materials for use in advanced structural applications in aerospace and defence industry. Ultrasonic characterization of these foams is performed extensively in order to understand the effect of porosity and particle size on the ultrasonic properties such as longitudinal velocity and attenuation. ...