Near-critical reflection of internal waves
Abstract
Internal waves describe the (linear) response of an incompressible stably stratified fluid to small perturbations. The inclination of their group velocity with respect to the vertical is completely determined by their frequency. Therefore the reflection on a sloping boundary cannot follow Descartes' laws, and it is expected to be singular if the slope has the same inclination as the group velocity. In this paper, we prove that in this critical geometry the weakly viscous and weakly nonlinear wave equations have actually a solution which is well approximated by the sum of the incident wave packet, a reflected second harmonic and some boundary layer terms. This result confirms the prediction by Dauxois and Young, and provides precise estimates on the time of validity of this approximation.
Keywords
Cite
@article{arxiv.1902.06669,
title = {Near-critical reflection of internal waves},
author = {Roberta Bianchini and Anne-Laure Dalibard and Laure Saint-Raymond},
journal= {arXiv preprint arXiv:1902.06669},
year = {2021}
}
Comments
accepted for publication by Analysis & PDE