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Seminario Especial de Matemáticas Aplicadas

CASCADES OF TRIADIC RESONANCE INSTABILITIES IN INTERNAL WAVES ATTRACTORS


por el

Dr. Ilias Sibgatullin

Department of Mechanics and Mathematics, Moscow State University, Russia

Resumen:
In contrast to the atmosphere of the Earth, the driving force of the Ocean is not a heat engine. Vertical mechanisms of energy transfer due to thermal processes and wind play signifcant role mostly in the vicinity of the surface of the Ocean. Meanwhile the global dynamics of the Ocean is also greatly aected by deep water processes and mixing. It means that now one of the most important questions in the dynamics of the oceans is related to the cascade of mechanical energy in the abyss and its contribution to mixing. Here, we propose internal-wave attractors in the large-amplitude regime as a unique self-consistent experimental and numerical setup that models a cascade of triadic interactions transferring energy from large- scale monochromatic input to multi-scale internal-wave motion. We also provide signatures of a discrete wave turbulence framework for internal waves. Beyond this regime, we have a clear transition to a regime of small-scale high-vorticity events which induce mixing. Also we have studied mixing due to boundary interaction and wave attractors formed from 3D sources of monochromatic waves in trapezoidal geometry.

1. C. Brouzet, S. Joubaud, E. Ermanyuk, I. Sibgatullin, T. Dauxois. Energy cascade in internal- wave attractors // Europhysics Letters.-2016.-113:44001-http://dx.doi.org/10.1209/0295- 5075/113/44001

2. C. Brouzet, I. Sibgatullin, H. Scolan, E. Ermanyuk, T. Dauxois. Internal wave attractors examined using laboratory experiments and 3d numerical simulations // Journal of Fluid Mechanics 2016.-Vol. 793.-P. 109-131.-http://dx.doi.org/10.1017/jfm.2016.119

Jueves 10 de noviembre, 2016.
18:00 hrs. Salón 203, Edificio Anexo, IIMAS

Informes: coloquiomym@gmail.com, o al 5622-3564.