L. Spicci, M. Cati
Esaote, Firenze, Italy
Ultrasound imaging probes are widely used for several types of diagnosis applications. In the present work we focus our attention on a disk-type probe, which is widely used in CW and PW operating conditions. In particular we present a 2D-axial symmetry FEM for the probe, capable to predict both the operative temperature values at different driving signal frequencies, both the heating dynamics. ...
C. Thiagarajan, G. Shenoy, B. S. Shenoy
ATOA Scientific Technologies Pvt Ltd, Whitefield, Bangalore, India.
Department of Mechanical & Manufacturing Engineering, Manipal Institute of technology, Manipal, India
Department of Aeronautical & Automobile Engineering, Manipal Institute of Technology, Manipal, India
Vibration and Dynamic performances of the rotating machinery are conventionally evaluated based on the dominant structural forces such as the centrifugal forces. The increase in rotational speed, miniaturization and performance, demands for improved and accurate evaluation of the vibration performance. The inclusion of coupled effects of fluid and centrifugal forces can contribute significantly ...
V.M. Acosta, E. Riera, G. Rodriguez, A. Pinto, A. Cardoni, J.A. Gallego-Juárez
Power Ultrasonics Group, CSIC, Serrano, Madrid, Spain
Pusonics, Arganda del Rey, Madrid, Spain
This work describes the design methodology and development of piezoelectric transducers for applications in fluids with COMSOL_Multiphysics. In these linear models for the acoustic-structure interaction approximate numerical solutions have been obtained. In order to perform the calculations, simplifications are only valid for low-power sound waves. Numerical modeling of piezoelectric transducers ...
Dinex Emission Technology A/S, Middelfart, Denmark
Exhaust noise must meet legislation targets, customer expectations and cost reduction which call for design optimization of the exhaust systems in the design phase. One solution is to use 3 dimensional linear pressure acoustics and calculate the transfer matrix of the muffler. The transfer matrix is the basis for calculating either the insertion loss or transmission loss of a muffler. The 3D ...
C. Van der Woude, and S. Narasimhan
University of Waterloo, Waterloo, ON, Canada
This paper presents a study of a wind turbine subjected to wind and seismic loading, carried out using COMSOL Multiphysics. The dynamic properties and response of wind turbine structures are of interest, as recent developments in wind energy have led to the design and construction of increasingly large and flexible turbine structures. A typical turbine structure model was created in ...
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. ...
J. Ratnieks, A. Jakovics, J. Klavins
Laboratory for Modeling Technological and Environmental Processes, University of Latvia, Riga, Latvia
A 2D numerical model for determination of sound reduction index is set up in this work. Results are in good agreement in middle and high frequency range when using solid structure approximation. Results are compared with experiment.
Castaings, M.1, Predoi, M.V.2, Hosten, B.1 1 Laboratoire Mécanique Physique, Univ. Bordeaux 1, UMR CNRS 5469, Talence, France
2 Catedra de Mecanica, Universitatea Politehnica Bucuresti, Bucuresti, Romania
Wave propagation in elastic waveguides is a problem of constant interest from the last decades. Several numerical approaches exist. The most intuitive uses time-marching routines that solve the equations of dynamic equilibrium and supply displacements of the structure nodes as time functions. This procedure is usually time and memory consuming due to huge number of temporal iterations required ...
ACOUSTICS@MBD CONSULTANTS, LLC, Westborough, MA, USA
There is a practical interest among composite materials manufacturers to high-speed accurate non-destructive evaluation (NDE) technology for voids inspection when these voids are natural components of such complex structures like resin insulated layer of double-sided copper-clad laminates. Model based design (MBD) of NDE system is one of principal solutions for voids inspection in such composites ...
G. Campa, E. Cosatto, S. Camporeale
Politecnico di Bari, Bari, Italy
Ansaldo Energia, Genova, Italy
A hybrid technique based on the use of the FEM and the transfer matrix method is used to identify the frequencies at which thermoacoustic instabilities are expected and the growth rate of the pressure oscillations at the onset of instability. The Helmholtz equation is used to model the combustion chamber and the classical ?-? formulation for the flame model is adopted. The gas turbine combustion ...