The Turbulent Diffusivity of Penetrative Convection

Daniel Lecoanet, Princeton U.

Wed Jan 25 at noon
Engineering Science Building, room 2001

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 penetration into the stable region. 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.

Daniel's comment: I'm basically showing that a QL/RNL model works well for describing simulations of convective mixing.