Thermal Convection From a Minimal Flow Unit to a Wide Fluid Layer

The computations of the ``minimal channel'' by Jim\'enez \& Moin (1991, JFM) provided a conceptual framework and building block from which to study the structure of near-wall turbulence driven by mean shear. Mean buoyancy, on the other hand, can sustain a vigorous field of very large eddies whose horizontal extent can extend across many full channel heights. We examine the extent to which a flow model consisting of a finite periodic array of such structures can successfully predict certain turbulence statistics in thermal convection with and without a mean flow in very large-aspect ratio channels.