[Seminario] INVITACIÓN SEMINARIO Mecánica Matemática y Problemas Inversos, JUEVES 14 DE MARZO A LAS 16:00 HRS.

[Maria Ines Rivera]

Estimados(as) Académicos(as) y Alumnos(as),

Se les invita para este jueves 14 de marzo a las 16:00 hrs, al 
Seminario  Mecánica Matemática y Problemas Inversos, el cual se 
realizará en la sala de Seminarios John  Von Neumann CMM, séptimo piso, 
torre norte de Beauchef 851.
*
SEMINARIO

**MECÁNICA MATEMÁTICA Y PROBLEMAS INVERSOS**
**
**EXPOSITOR

**Miguel D Bustamante**
**Associate Professor**
**School of Mathematics and Statistics**
**University College Dublin**
**Belfield, Dublin 4**
**IRELAND**
**
**TITULO

**Energy flux enhancement, intermittency and turbulence via Fourier 
triad phase dynamics in the 1-D Burgers equation.**
**
**Abstract*: We present a theoretical and numerical study of Fourier 
space triad phase dynamics in 1-D stochastically forced Burgers equation 
at Reynolds number Re ≈ 27000. We show that Fourier triad phases over 
the inertial range display a collective behaviour characterised by 
intermittent periods of synchronisation and alignment, reminiscent of 
Kuramoto model (1984) and directly related to shock collisions in 
physical space. These periods of synchronisation favour efficient energy 
fluxes across the inertial range towards small scales, resulting in 
strong bursts of dissipation and enhanced coherence of Fourier energy 
spectrum. The fast time scale of the onset of synchronisation relegates 
energy dynamics to a passive role: this is further examined using a 
reduced system where Fourier amplitudes are fixed in time -- a 
phase-only model. In it, we find intermittent triad phase dynamics 
without amplitude evolution and recover many features of the full 
Burgers system. Finally, for both full Burgers and phase-only systems 
the physical space velocity statistics reveal that triad phase alignment 
is directly related to the non-Gaussian statistics typically associated 
with structure-function intermittency in turbulent systems. This work 
was done in collaboration with Brendan P. Murray, and is published in 
JFM 850, 624-645 (2018).

JUEVES 14 DE MARZO A LAS 16:00 HRS, SALA DE SEMINARIOS JOHN VON NEUMANN 
CMM, SÉPTIMO PISO, TORRE NORTE DE BEAUCHEF 851.

Esperando contar con su presencia, les saluda,

Ma. Inés Rivera

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