J. P. Sandoz, J. M. Kissling
Institute of Applied Microtechnology, La Chaux-de-Fonds, HE‐ARC, Switzerland
In this contribution we present a COMSOL Multiphysics® example of a disk piezoelectric ceramic transformer (D-PT) coupled with a bipolar NPN transistor to form an auto-oscillator. The comparison between the simulations and the measurements made on our prototype are found to be in good agreement. Having at our disposal a large number of homogenously poled disks, we decided to build and to ...
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 ...
University of the West of Scotland, Paisley, Renfrewshire, UK
The Jecklin Disk is a sound absorbing disk placed between two omnidirectional microphones. It is used to recreate some of the frequency-response, time and amplitude variations human listeners’ experience, but in such a way that the recordings also produce a useable stereo image through loudspeakers. This paper presents a finite element model able to simulate the effects on sound propagation ...
M. Yeoman, V. Sivasailam, A. Tomar
Continuum Blue Ltd., Ystrad Mynach, UK
Jaguar Land Rover Ltd, Coventry, UK
The design of windows and or other perforated structures which allow the free flow of air into & out of a building or system, while being fully soundproofed or attenuate certain frequencies is of great interest to architects and design engineers, where sound as a longitudinal wave, is difficult to separate it from its medium of propagation. In this work, we present the analysis of air ...
M. J. Herring Jensen 
 COMSOL A/S, Lyngby, Denmark
In this session, we will discuss and showcase a few examples of advanced acoustics applications. In this context, “advanced” means problems that cannot simply be modeled “out-of-the-box,” but require the flexibility and strengths of COMSOL Multiphysics® software. Topics include: • Coupling of several space dimensions • Optimization • Equation-based modeling • Advanced boundary ...
L. Fromme , J. Waßmuth , D. Wehmeier ,
 Bielefeld University of Applied Sciences, Bielefeld, Germany
The knowledge of the acoustical transfer paths in active noise control systems is very important for the performance of the system. Unfortunately, simulation is challenging since even simple configurations require comprehensive experience in physics and modeling. Two test setups were chosen for basic investigations on modeling, simulation and validation. The first results presented here are ...
D. Neihguk , M. L. Munjal , A. Prasad ,
 Mahindra & Mahindra Ltd, Chennai, India
 Indian Institute of Science, Bangalore, India
Perforated pipes are extensively used to control exhaust noise in automobiles [1-4]. The energy loss associated with the perforations leads to back pressure which needs to be quantified and minimized . An objective approach presented in  is the introduction of friction factor for perforated ducts as a function of the porosity. In this article, the utilization of the CFD Module of COMSOL ...
A. Giusti, A. Andreini, B. Facchini, F. Turrini, Ignazio Vitale
Department of Energy Engineering, University of Florence, Florence, Italy
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 ...
E. Lacatus, G. C. Alecu, A. Tudor, M. A. Sopronyi
Polytechnic University of Bucharest, Bucharest, Romania
Student-Polytechnic University of Bucharest, Bucharest, Romania
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, ...
V. Romero-García, A. Krynkin, J.V. Sánchez-Pérez, S. Castiñeira-Ibáñez, and L.M. Garcia-Raffi
Centro de Tecnologías Físicas Acústica, Universidad Politécnica de Valencia, Valencia, Spain
School of Computing, Science & Engineering, University of Salford, Salford, United Kingdom
Depto. Física Aplicada, Universidad Politécnica de Valencia, Valencia, Spain
Instituto Universitario de Matemática Pura y Aplicada, Universidad Politécnica de Valencia, Valencia, Spain
The elastic and geometrical properties of Low Density Polyethylene (LDPE) foam are used in this paper to improve the attenuation properties of periodic arrangements of acoustic scatterers known as Sonic Crystals (SCs). A specific recycled profile of LDPE foam is used as elastic-acoustic scatterer. The acoustic spectrum of the single scatterer shows two attenuation peaks in the low frequency ...