Lind, R.J., Abedian, B.
Department of Mechanical Engineering Tufts University, Medford, Massachusetts
This presentation is a numerical study of fluid flow around a two-dimensional rigid flapping plate and its effects on the resultant transient heat transfer effects on the solid interface. In this study, a flat inflexible thin plate surrounded by air undergoes sinusoidal angular motion from one end while the other end is kept stationary, simulating a flapping motion. The two-dimensional ...
L. Martinelli, and A. Lamberti
Universita di Bologna, Italy
Objective of this contribution is to show how to implement the Mild Slope Equations with COMSOL Multiphysics. These equations are commonly used to study the propagation of waves in harbors. Some interesting features are presented, namely the use of weak terms (used for the modelling of the source term); the evaluation of a smooth phase gradient from the complex dependent variable; a robust ...
Design of a MEMS Resonator for a Centre Frequency Greater than 26.35 MHz and Temperature Coefficient Frequency Less than 0.5 ppm
S.Manikandan, R.Radeep krishna
Kalasalingam University, Department of ECE, Srivilliputtur ,Krishnan koil, Tamil Nadu, India
The variability of the design parameters caused by material properties like thermal conductivity is the major challenge in Micro Electromechanical System (MEMS). In resonator design the basic problem is that the frequency changes with temperature variation and quantitative explanation with respect to this varies. The change can be attributed to the stability in terms of frequency drift in parts ...
K. Anderson, A. Smith, D. Forgette
Mechanical Engineering, California State Polytechnic University at Pomona, Nonlinear FEM/CFD Multiphysics Simulation Lab, Pomona, CA, USA
In this poster the acoustic analysis of a small home recording studio is presented.. Figure 1 illustrates the recording studio room which was simulated using the COMSOL Multiphysics® software with the Acoustics Module . The propagation of sound is modeled as pressure waves in which modal analysis is performed in the frequency domain . Lower eigen-frequencies are the most critical to ...
Simulation Analysis of Acoustic Radiation Force under Ultrasound Exposure and Effect to Microbubbles in Flow
Tokyo University of Agriculture & Technology
This paper is in Japanese.
L.B.M. Silva, E.J.P. Santos
Laboratory for Devices and Nanostructures, Electronics and Systems Department, Universidade Federal de Pernambuco, Recife, PE, Brasil
Transducer optimization is a key aspect for successful development and deployment of advanced sensors, especially when designing 3D structures for harsh environments. For piezoelectric transducers, plate thickness determines the operating frequency of the resonator, which is frequently tuned in the shear thickness vibration mode. Quartz has been the material of choice for the fabrication of bulk ...
Glass Plates Noise Transmission Suppression by Means of Distributed Piezoelectric Composite Actuators Shunted by an Active Circuit
K. Novakova, P. Mokry
Research Centre for Special Optics and Optoelectronic Systems (TOPTEC), Institute of Plasma Physics, Academy of Sciences of the Czech Republic, Turnov, Czech Republic
Institute of Mechatronics and Computer Engineering, Technical University of Liberec, Liberec, Czech Republic
Glass windows represent a virtual sound source for buildings interior. It is very easy to make them vibrate by action of incident acoustic pressure wave. Therefore, non-negligible part of the wave is transmitted through the window. We propose and simulate a method based on the change of mechanical properties of the plate using flexible piezoelectric Macro Fiber Composite actuators distributed on ...
K. Koppenhoefer, S.Yushanov, and M.H. McKenna
AltaSim Technologies, LLC, Columbus, Ohio, USA
U.S. Army Engineering Research and Development Center
Aging infrastructure requires frequent inspections to assess their structural integrity. However, the large amount of existing infrastructure, and the distance between these structures present significant challenges to inspectors. Acoustics-based technologies represent a simple, and relatively inexpensive, technique to monitor the integrity of a structure. To develop these techniques, designers ...
G. Rosi, L. Teresi, A. DiCarlo, and F. dell'Isola
LaMS - Università degli Studi Roma Tre, Roma, Italy
Università degli Studi di Roma "La Sapienza", Roma, Italy
Liquid crystals - as all liquids - are generally modelled as incompressible media. In fact, mass-density changes occurring in these mesophases are minuscule and inconsequential in most regimes of interest. However, liquid crystals exhibit also phenomena that call for a more refined theory. In particular, it is experimentally well established that the Fréedericksz transition - i.e., the sudden ...
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 ...