Numerical simulation of parametric sound generation and its application to length-limited sound beam

Document type: Journal Articles
Article type: Original article
Peer reviewed: Yes
Author(s): Hideyuki Nomura, Claes Hedberg, Tomoo Kamakura
Title: Numerical simulation of parametric sound generation and its application to length-limited sound beam
Journal: Applied Acoustics
Year: 2012
Volume: 73
Issue: 12
Pagination: 1231-1238
ISSN: 0003-682X
Publisher: Elsevier
URI/DOI: 10.1016/j.apacoust.2012.02.016
ISI number: 000308730300004
Organization: Blekinge Institute of Technology
Department: School of Engineering - Dept. of Mathematics & Natural Sciences (Sektionen för ingenjörsvetenskap - Avd.för matematik och naturvetenskap)
School of Engineering S-371 79 Karlskrona
+46 455 38 50 00
Language: English
Abstract: In this study we propose a simulation model for predicting the nonlinear sound propagation of ultrasound beams over a distance of a few hundred wavelengths, and we estimate the beam profile of a parametric array. Using the finite-difference time-domain method based on the Yee algorithm with operator splitting, axisymmetric nonlinear propagation was simulated on the basis of equations for a compressible viscous fluid. The simulation of harmonic generation agreed with the solutions of the Khokhlov-Zabolotskaya-Kuznetsov equation around the sound axis except near the sound source. As an application of the model, we estimated the profiles of length-limited parametric sound beams, which are generated by a pair of parametric sound sources with controlled amplitudes and phases. The simulation indicated a sound beam with a narrow truncated array length and a width of about one-quarter to half that of regular a parametric beam. This result confirms that the control of sound source conditions changes the shape of a parametric beam and can be used to form a torch like low-frequency sound beam.
Subject: Physical Acoustics\General
Keywords: Nonlinear sound propagation, Parametric acoustic array, Length-limited sound beam, Numerical simulation, Finite-difference time-domain (FDTD) method
Note: Special Issue