  Turbulent motions in the interior of a star play an important role in its
evolution, since they transport chemical species, thermal energy and angular
momentum. Our overall goal is to construct a practical turbulent closure model
for convective transport that can be used in a multi-dimensional stellar
evolution calculation including the effects of rotation, shear and magnetic
fields. Here, we focus on the first step of this task: capturing the well-known
transition from radiative heat transport to turbulent convection with and
without rotation, as well as the asymptotic relationship between turbulent and
radiative transport in the limit of large Rayleigh number. We extend the
closure model developed by Ogilvie (2003) and Garaud and Ogilvie (2005) to
include heat transport and compare it with experimental results of
Rayleigh-Benard convection.
