Scalings and structures in natural thermal convection

Turbulent thermal convection which occurs due to the temperature differences imposed at the boundaries of the domain is omnipresent in nature in technology. In this talk, we will focus on Rayleigh-Benard convection but also consider some other flow configurations: vertical and horizontal convection. For these systems, we will discuss the problem of scaling relations of the global heat and momentum transport, the proper boundary layer equations, and the large-scale flow organization. We will show that in some cases, the scaling of the global heat transport and the temperature profiles can be predicted by solving the proper boundary-layer equations that include turbulent fluctuations and correct boundary conditions. For Rayleigh-Benard convection, we will discuss also the onset of convection in slender containers, the proper length scales, and the formation of global flow structures in turbulent regimes.