G. Zhu, E.M. Dede
Toyota Research Institute of North America, Ann Arbor, MI, USA
In previous work, a two-dimensional (2D) model was carried out to simulate the phononic band structure of a phononic crystal with square lattice structure, but this model did not account for the out-of-plane phonon dispersions . In fact, for 2D films used for coating materials, it is more interesting to understand their cross-plane properties. In this work, the phonon dispersion relation of ...
Simulating Acoustic Combustion Chamber Eigenmodes to Facilitate Combustion Stability in Rocket Engines
R. Kaess , J. Braun ,
 Airbus Safran Launchers, Ottobrunn, Germany
Airbus Safran Launchers is the market leader in Space Launch services. Rocket engines are among the most powerful machines that exist. The core of the rocket engine is the combustion chamber where in the case of liquid propellant rocket engines, fuel and oxidizer are injected, mixed and burnt and where, consequently, the energy release takes place. The hot combustion gases are accelerated in a ...
V. Vadde, and B. Lakshmi G
In this paper, we develop and analyze a standard piezoacoustic Tonpilz-transducer model for underwater acoustics in Comsol by addressing the attendant piezoelectric and pressure acoustic multiphysics phenomena. Transducer properties that are studied and characterized are the center frequency, bandwidth, linearity, sensitivity, and noise figure. In an effort to miniaturize the transducer, a ...
韩建宁 , 罗世通 ,
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。
JBL Professional, Northridge, CA, USA
The author presents an overview of methods to build virtual prototypes of both horns and loudspeaker drivers which allows a significant reduction in the number of physical prototypes, as well as reduced development time. This paper will present some of the practical results from work the author has performed in the course of designing both transducers and horns using COMSOL Evolution of the ...
J. M. Stauber , B. A. Marmo ,
 Xi Engineering Ltd, Edinburgh, United Kingdom
Tonal noise from wind turbines can have effects on neighboring residences and its emission can result in strong regulatory penalties that can include the closure of wind farms. The authors present a model of a new broadband damping approach where containers filled with EniDamp™, an Advance Particle Damping (APD) material. The containers, so-called APD pods, are magnetically fixed to wind ...
Poznan University of Technology
This paper concerns the problem of obtaining proper acoustic attenuation performance through computations. COMSOL was used to solve acoustics systems with helicoidal resonators in the frequency domain. Based on the studies of insertion and transmission loss of helicoidal resonators, a high consistency between the results obtained by numerical calculations with experimental measurements was ...
Study & Modeling of 'Acoustic Matching Layers' for Ultrasound Imaging Probes Through Pulse-Echo FEM Simulation - new
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 ...
R. Christensen ,
 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 ...
W. Chalgham , A. C. Seibi ,
 University of Louisiana at Lafayette, Lafayette, LA, USA
Pipeline inspection tools present some limitations related to power supply which require recharging after each operation. Using batteries or tethered tools make the duration to inspect any pipeline very limited and time consuming. This paper aims at designing a spherical self-recharging untethered mobile ball flowing inside a given pipeline using the COMSOL Multiphysics® software. The ball will ...