Structures, boundary layers and plumes in turbulent Rayleigh-Bénard convection

Rayleigh-Bénard convection is a fluid driven by temperature differences between a top and a bottom plate. An important and interesting quantity is the heat transport through the system. Obtaining accurate estimates on how this scales with the temperature difference is the goal of a large scientific effort. A low driving, the flow is laminar or there is no convection present at all. Stronger driving, i.e. a larger temperature difference, results in turbulent flow. The turbulence exists at first far from the plates and thus the boundary layers remain laminar. This regime of thermal convection is accessible by numerical and experimental studies and is well understood theoretically. In this thesis the theory is improved using recent data from the scientific community. Astro –and geophysical applications of thermal convection are fully turbulent and inaccessible for contemporary experiments and numerics. This is why in this research the behavior of the structures, boundary layers and thermal plumes are studied in two –and three-dimensional systems at as high driving as possible using state-of-the-art supercomputers. In addition, the performance of the used numerical codes has been improved in order to facilitate an accurate extrapolation of the available data to these inaccessible regimes.