The Turbulent Diffusivity of Convective Overshoot
Orateur : Daniel Lecoanet
UC-Berkeley, USA
Résumé : There are many natural systems with convectively unstable fluid adjacent to stably stratified fluid ; including the Earth’s atmosphere, most stars, and perhaps even the Earth’s liquid core. The convective motions penetrating into the stable region can enhance mixing, leading to changes in transport within the stable region. In this talk, I will present convective overshoot simulations, in which I quantitatively measure the extra mixing due to overshoot. This extra mixing can be accurately modeled as a turbulent diffusivity. I will then apply the turbulent diffusivity measurements to the astrophysical problem of mixing in convectively bounded carbon flames.
Date et lieu : le Vendredi 8 Février 2016 à 11h00, salle de séminaire IRPHE