Energy dissipation in rotating turbulence
Orateur : Basile Gallet
SPEC - CEA Saclay
Résumé : Rapidly rotating turbulence is present in many different contexts, ranging from industrial flows to atmospheric and oceanic motions. In these situations, the turbulent energy dissipation rate is a key quantity : engineers want to optimize the power efficiency, while oceanographers and climate scientists want to parametrize turbulent energy dissipation in the ocean-atmosphere coupled system. Finally, the dissipated power is the central quantity of the Obukhov-Kolmogorov theory of turbulence.
I will present two experiments aimed at studying the influence of global rotation on the energy dissipation rate : does the turbulent flow present a dissipation anomaly, like 3D turbulence, or does it dissipate energy at a laminar rate, like 2D turbulent flows ? How is the drag coefficient of a moving object affected by global rotation ?
This experimental work is supplemented by recent theoretical progress proving that a large class of rotating flows becomes exactly two-dimensional at low Rossby number, with no energy dissipation anomaly.
Date et lieu : le Vendredi 27 Novembre 2015 à 11h00, salle de séminaire IRPHE