Abstract
The propagation of intense acoustic waves in a periodic medium (often referred as a sonic crystal) is numerically studied. The medium consists in a structured fuid, formed by a periodic array of uid layers with alternating linear acoustic properties and quadratic nonlinearity coefficient. The spacing between layers is of the order of the wave-length; therefore Bragg effects such as band-gaps appear. We show that the interplay between strong dispersion and nonlinearity leads to new scenarios of wave propagation. The classical waveform distortion process typical of intense acoustic waves in homogeneous media can be strongly altered when nonlinearly generated harmonics lie inside or close to band gaps. This allows the possibility of engineer a medium in order to get a particular waveform. Examples of this include the design of media with effective (e.g. cubic) nonlinearities, or extremely linear media (where distortion can be cancelled). In two dimensions, the situation is more complex but the same ideas introduced in 1D case remain valid. As an example, we report the propagation of an intense acoustic beam in a sonic crystal under self-collimation conditions. The presented ideas open a way towards the control of acoustic wave propagation in non-linear regime.
BibTeX citation
@inproceedings{Sanchez-Morcillo2015a,
author = {Víctor Sánchez-Morcillo and Noé Jiménez and Ahmed Mehrem and El Mohktar Hamham and Lluis García-Raffi and Rubén Picó},
booktitle = {ICU 2015: International Congress on Ultrasonics. Metz, France. May 11-14,},
doi = {https://doi.org/10.1016/j.phpro.2015.08.152},
editor = {Physics Procedia},
month = {5},
organization = {Georgia Tech Lorraine},
pages = {271-274},
publisher = {Elsevier},
series = {Oral},
title = {Propagation of Intense Acoustic Waves in Sonic Crystals},
url = {https://www.sciencedirect.com/science/article/pii/S1875389215008937},
volume = {70},
year = {2015}
}