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.

Simulação de um Sistema de Levitação Acústica para Manipulação de Partículas em Ar

M. A. B. Andrade [1], N. Pérez [2], J. C. Adamowski [3],
[1] Instituto de Física, Universidade de São Paulo, São Paulo, SP, Brasil
[2] Centro Universitario de Paysandú, Universidad de la República, Paysandú, Uruguai
[3] Departamento de Engenharia Mecatrônica e Sistemas Mecânicos, Escola Politécnica, Universidade de São Paulo, São Paulo, SP, Brasil

Este trabalho apresenta a simulação numérica de um sistema de levitação acústica para manipulação de partículas em ar. O sistema de levitação consiste de dois transdutores de ultrassom e um refletor de face plana. Através da simulação é calculado o potencial da força de radiação acústica que atua numa esfera. Os resultados da simulação são verificados experimentalmente através da comparação da ...

Numerical Study on the Mechanism of Interface Debonding Detection for CFST with PZT

H. Chen [1], J. Li [1], S. Xia [2],
[1] Hunan University, Changsha, Hunan, China
[2] Xi'an Jiaotong University, Xi'an, Shaanxi, China

Introduction In order to understand the detection mechanism of the PZT based nondestructive testing (NDT) technology for interface debonding of CFSTs, numerical simulation on a multi-physical model composed of surface-mounted PZT patches and CFST structural member is established in COMSOL Multiphysics®. The stress propagation process and the electrical signal output of an embedded PZT patch as ...

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 ...

Towards Rotordynamic Analysis with COMSOL Multiphysics

M. Karlsson[1]
[1]ÅF, Stockholm, Sweden

In this paper a pre-study on using COMSOL Multiphysics for rotordynamic analysis is presented. It is concluded that it is possible to use COMSOL Multiphysics to perform rotordynamical analysis. However, there are no standard environment for rotordynamics, hence the user has to extend the structural model with the rotordynamics effect such as gyroscopic effect and rotordynamical coefficients. By ...

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 ...

Phase Decomposition for Loudspeaker Analysis

R. Christensen [1],
[1] GN ReSound A/S, Copenhagen, Denmark

The vibration of an electrodynamic loudspeaker driver causes a resulting sound pressure. For simple pistonic vibration, there is a simple relationship between the vibration and the sound pressure. For complex vibration patterns, however, different parts of the vibrating surface contribute differently to the sound pressure, depending on the position in which the sound pressure is evaluated. A ...

Design of Ultrasonic MEMS Temperature Sensor Using COMSOL Multiphysics® Software

S. K. Kamilla [1], G. Parag [1], H. Tripathy [1], P. Pattanaik [1],
[1] Semiconductor Research Lab, ITER, Siksha 'O' Anusandhan University, Bhubaneswar, Odisha, India

The attempt has taken to miniaturized size of non contact temperature sensor by using ultrasonic trans-receiver. The piezoelectric material is used in both transmitter and receiver ends for this ultrasonic Micro-Electronics Mechanical Systems (MEMS) based temperature sensing device. Prior to fabrication of ultrasonic MEMS device, design and simulation are extensively used to avoid wastage of ...

Design of Electroacoustic Absorbers Using PID Control

H. Lissek, R. Boulandet, and M. Maugard
Ecole Polytechnique Federale de Lausanne
Lausanne, Switzerland

An \"electroacoustic absorber\" is a loudspeaker, used as an absorber of sound, which acoustic impedance can be varied by electrical means. This can be achieved either by plugging passive shunt electric networks at the loudspeaker terminals (“shunt loudspeakers”) or by feeding back the loudspeaker with a voltage proportional to acoustic quantities, such as sound pressure and diaphragm normal ...

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 ...

Thermo-Acoustic Analysis of an Advanced Lean Injection System in a Tubular Combustor Configuration

A. Giusti[1], A. Andreini[1], B. Facchini[1], F. Turrini[2], Ignazio Vitale[2]
[1]Department of Energy Engineering, University of Florence, Florence, Italy
[2]Avio, Turin, Italy

In this work a thermoacoustic analysis of a tubular combustor with an advanced lean injection system is presented. The performed analysis is based on the resolution of the eigenvalue problem related to an inhomogeneous wave equation which includes a source term representing heat release fluctuations (the so called Flame-Transfer-Function, FTF) in the flame region. The effect of the mean flow is ...