H. Zhang, W. Lin, and X. Wang
Chinese Academy of Sciences, Institute of Acoustics, Beijing, China
Acoustical well logging is an important technology for petroleum industry. Calibration and testing of tools in real wells is not feasible because the cost is high and the condition is not controllable. During manufacturing and maintaining, the logging tools are usually tested in a fluid filled circular pipe. The acoustic field in non-circular wells are calculated by using of the PDE mode of ...
G.D. Cole, M. Aspelmeyer, and I. Wilson-Rae
University of Vienna, Vienna, Austria
Technical University Munich, Munich, Germany
Micro-and nanoscale mechanical resonators have recently emerged as ubiquitous devices for use in advanced technological applications, for example in mobile communications and inertial sensors, and as novel tools for fundamental scientific endeavors. We report a significant advancement towards understanding and controlling support-induced losses through the demonstration of an efficient numerical ...
Two-Dimensional FEM Analysis Of Brillouin Gain Spectra In Acoustic Guiding And Acoustic Antiguiding Single Mode Optical Fibers
Y.S. Mamdem, X. Pheron, F.Taillade, Y. Jaouën, R. Gabet, V. Lanticq[1,3], G. Moreau, A. Boukenter, Y. Ouerdane, S. Lesoille, and J. Bertrand
EDF R&D, Chatou, France
ANDRA, Chatenay-Malabry, France
LCPC, Paris, France
Telecom ParisTech, Paris, France
Laboratoire Hubert Curien, Saint-Etienne, France
We present a full modal -analysis of optical and acoustic properties based on two-dimensional finite-element method (2D-FEM) for Brillouin Gain spectrum (BGS) determination in optical fibers with COMSOL. This model enables us to predict precisely the BGS of any kind of silica fiber knowing well the geometry of doping composition. The results of numerical modeling have shown good agreement in ...
S. Floody, R. Venegas, and F. Leighton
Universidad de Chile, Facultad de Artes, Departamento de Música y Sonología, Licenciatura en Sonido, Santiago, Chile
University of Salford, Acoustics Research Centre, Salford, UK
Universidad Tecnológica de Chile Inacap, Sede Pérez Rosales, Santiago, Chile
The present article presents a method to redistribute the acoustic modes of a rectangular enclosure in the low frequency range using slit resonators. The objective of the present work is to compare different strategies of optimal design in order to determine the dimensions of the resonators. The method of the finite elements will be used to model the acoustic physical behavior of the room. In ...
B. Marmo, and B. Carruthers
Reactec Ltd., Edinburgh, United Kingdom
The onshore wind turbine industry must overcome many technical, commercial, and environmental difficulties. A significant element for planning consent is operational noise. Acoustic limits are strictly enforced and can lead to near-neighbour complaints as well as contractual disputes. Reactec have diagnosed, analysed and solved a problematic tonal resonance for a major wind turbine generator ...
J. Ratnieks, A. Jakovics, and J. Klavins
University of Latvia
Although we know the physics inside a media where the sound waves propagate, determination of material\'s or structure\'s sound reduction index is not an easy task. The lack of good engineering solutions proves the point. The only reliable way to calculate the sound reduction index is to carry out an experiment.Therefore, the aim of this study is to develop a mathematical model that can ...
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 ...
Modeling Thermal Bridging at Interface Conditions: Analysis of Solutions for Reducing Thermal Bridges Effects on Building Energy Consumption
C. Balocco, E. Marmonti
Dipartimento di Energetica, Università di Firenze, Firenze, Italy
In Europe considerable building activity can be expected over the coming decades; Net Zero Energy Buildings refers to a building with minimal power, until maximum 15 kW/m^2. In both cases this requires very well insulated buildings with minimal thermal bridges. Concrete balconies, that extend the floor slab through the building envelope, are a common example of thermal bridging, where structural ...
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 ...
Modeling and Experimental Verification of the Power Transfer and Thermal Characteristics of Piezoelectric Transformers Subjected to Combined Mechanical and Electrical Loading
S. Tuncdemir, W.M. Bradley
Solid State Ceramics, Williamsport, PA, USA
QorTek, Williamsport, PA, USA
A piezoelectric transformer allows purely mechanical transfer and scaling of electrical energy via simultaneous utilization of both the direct and converse piezoelectric effects. This mechanical energy transfer enables a wide range of functional differences from typical magnetic-based electrical power transformers. Comparing to their electromagnetic counterparts, piezoelectric transformers are ...