John Wettlaufer - Yale University The scaling of the Nusselt number Rayleigh number relationship in Rayleigh-Benard convection has long been known to reside in the nature of the interaction between the boundary layers and the interior of the flow. Experiments have been designed to manipulate that interaction by deliberately tailoring the geometry of the surfaces in convection cells. Here we use numerical simulations to study the effects of periodically roughened boundaries (one upper or an upper and lower boundary) in optimizing the heat transport at a particular wavelength at fixed amplitude, as well as the influence of a fractal upper boundary and its properties.