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 ...
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. ...
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 ...
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 ...
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 ...
COMSOL Multiphysics® Software for Simulation of Surface Response to Excitation Method for Manufacturing Process Performance Monitoring - new
H. Fekrmandi, N. Miniello, R. Kiflemariam, I. Nur Tansel
Mechanical & Materials Engineering Department, Florida International University, Miami, FL, USA
In this study, COMSOL Multiphysics® software was used to simulate the surface response to excitation method (SuRE). An aluminum beam with a piezoelectric element bonded is modeled using the COMSOL Acoustics Module. A frequency domain sweep study was performed to simulate the sweep sign generation. The frequency spectrum of the structure is monitored through a frequency range of (20kHz-400kHz). A ...
A. Arevalo , D. Castro , D. Conchouso , I. G. Foulds 
 Computer, Electrical and Mathematical Sciences and Engineering (CEMSE), King Abdullah University of Science and Technology (KAUST), Saudi Arabia
 The University of British Columbia, School of Engineering, Okanagan Campus, Saudi Arabia
For our simulation we used the Piezoelectric Devices interface. The structure was set with (clamped) fix constraint boundaries to both ends. The bottom electrode was set to be the ground for the electrostatic physics and the top electrode was set to be a Terminal with potential of 10V. A parametric sweep study was set to change the geometry, the parameters to change was the hole diameter (Holed) ...
V. Chatziioannou, and W. Kausel
Institute of Music Acoustics
University of Music and Performing Arts
The vibration of the walls of brass wind instruments has been a subject of study in the field of musical acoustics throughout the last decades. The amplitude of such vibrations, stimulated by the oscillating air pressure inside the instrument bore, is very small compared to the dimensions of the instrument. However, it has been recently shown that at the flaring regions of the bell of brass ...
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 ...
陆晓 , 温周斌 ,
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。 ...