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.
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COMSOL-News-Magazine-2016

Analysis of High-Frequency Thermoacoustic Instabilities in Lean, Premixed Gas Turbine Combustors

F. Berger [1], T. Hummel [1], P. Romero [1], M. Schulze [1], B. Schuermans [2], T. Sattelmayer [1],
[1] Lehrstuhl für Thermodynamik, TU München, Germany
[2] GE Power, Switzerland

Modern gas turbine systems for power generation are prone develop so-called thermosacoustic instabilities in the combustion chamber. Physically, these instabilities emerge as large amplitude pressure oscillations within the combustor, which are caused by constructive feedback interactions between the flame and the combustor's natural acoustic modes. The oscillations disturb the combustion ...

PCCP Profiling and Tube Wave Analysis of WRE Signal

N. Chowdhury[1], Z. Liao[2], and L. Zhao[1]
[1]Department of Electrical & Computer Engineering, Ryerson University, Toronto, ON, Canada
[2]Department of Architectural Science, Ryerson University, Toronto, ON, Canada

Acoustic wave propagation due to the breakage or slippage of reinforced wire in water-filled prestressed concrete cylinder pipe (PCCP) attracts interest in non-destructive pipe testing. Current practice of acoustic emission (AE) detection and wire-break related events (WRE) recognition is based on field data analysis. This work deals with the theoretical investigation of WRE signal from ...

Design and Simulation of an Orbiting Piezoelectric MEMS Gyroscope Based on Detection of Phase-Shift Signals - new

S. Gorelick[1], J. R. Dekker[1], B. Guo[1], H. Rimminen[1]
[1] VTT Technical Research Centre of Finland, Espoo, Finland

The feasibility of phase-sensitive detection of angular-rates using bi-directional orbiting piezoresonators suspended by thick annular springs with thin-film aluminium nitride piezoactuators on top of them was investigated. The ring-shaped flexures are more suitable for supporting the orbiting motion due to their angle-dependent spring constant. The response of the orbiting resonators to ...

安装在有限大障板上的轴对称扬声器特性的近似计算方法

陆晓 [1], 温周斌 [1],
[1] 浙江中科电声研发中心,嘉善,浙江,中国

使用 COMSOL Multiphysics® 仿真轴对称扬声器一般可采用 2D 轴对称模型,但在这种坐标系下无法建立扬声器测量中常用的矩形障板模型,而选择计算安装在无限大障板上扬声器的声特性,其仿真计算结果又与常见的标准障板上的测量结果在中低频段存在较大差异。 为了使无限大障板上的仿真结果与标准障板(或其它有限大障板)上的测量结果相一致,提出一种方法,利用 COMSOL 软件的 Parameter Sweep 功能,通过多次进行 2D 轴对称的电磁场、结构力学和声学三场耦合的扬声器仿真计算及相应后处理,得到安装在有限大障板上的扬声器正前方的声特性。 采用该方法可在较短时间内比较准确地计算得到安装在任意形状的有限大障板上的扬声器的声压级和谐波失真等特性。如图1和图2所示,采用该方法得到的声压级和总谐波失真曲线(红色),与测量结果(黑色)趋势和细节都比较一致。 ...

Optimization of an Acoustic Waveguide for Professional Audio Applications

M. Cobianchi[1] and R. Magalotti[1]
[1] B&C Speakers S.p.a., Bagno a Ripoli, FI, Italia

In modern live sound reinforcement there is a growing use of line sources, obtained through the stacking of many loudspeakers with properly controlled wavefront shape. Thus the use of waveguides is mandatory in order to modify the shape and size of the wavefront exiting from professional compression drivers. With the help of COMSOL Multiphysics®, we have designed a waveguide featuring an ...

Phonon Tunneling Loss Solver for Micro- and Nanomechanical Resonators

G.D. Cole[1], M. Aspelmeyer[1], and I. Wilson-Rae[2]
[1]University of Vienna, Vienna, Austria
[2]Technical University Munich, Munich, Germany

Micro-and nanoscale mechanical resonators have recently emerged as ubiquitous devices for use in advanced technological applications, for example in mobile communications and inertial sensors, and as novel tools for fundamental scientific endeavors. We report a significant advancement towards understanding and controlling support-induced losses through the demonstration of an efficient numerical ...

A Study into the Acoustic and Vibrational Effects of Carbon Fiber Reinforced Plastic as a Sole Manufacturing Material for Acoustic Guitars

J. O'Donnell[1], G. McRobbie[1]
[1]University of the West of Scotland, Paisley, Scotland, United Kingdom

This study will research a modern design of acoustic guitar by analysis of the vibrational modes. The guitar that will undergo testing has been provided by Emerald Guitars and is solely constructed using Carbon Fiber Reinforced Plastic (CFRP). With the use of COMSOL Multiphysics© the soundboard of the guitar will be simulated and analysis will be carried out to determine the first 10 ...

Acoustic Streaming of a Sharp Edge

M. Ovchinnikov[1]
[1]Alcon Research Ltd., Lake Forest, CA, USA

Anomalous acoustic streaming is observed from sharp edges of vibrating solid bodies in fluids. The streaming velocities can be orders of magnitude higher than expected from the Rayleigh streaming at similar amplitudes of vibrations. Acoustic velocity of a fluid relative to a solid body diverges at a sharp edge giving rise to a localized time-independent body force acting on the fluid. The ...

Underwater Flow Noise Simulation

S. H. Abadi [1], A. T. Lim [1],
[1] University of Washington, Bothell, WA, USA

Underwater acoustics is an area that studies the sound propagation in water and the interactions with other objects and water boundaries. There are many technologies available for acoustic exploration of the ocean. Underwater vehicles are robots used in ocean sciences that travel underwater autonomously and can tow a hydrophone as a mobile sensor to record sound. The turbulent flow induced by ...

Vibration Analysis of Rectangular Perforated Plates by COMSOL Multiphysics® Software

B. Raghavendra[1]
[1]SRM University & BITS Pilani University, Chennai, Tamil Nadu, India

Vibration analysis of perforated plates is extremely important when designing structures where resonance is the possible mode of failure. This paper deals with the vibration analysis of rectangular perforated plates with three different types of perforations. Vibration analysis is to be carried out by both COMSOL Multiphysics® Software and Experimental set-up. The applications of perforated ...