Long-term unsteadiness and large-scale structures in Rayleigh-Bénard convection with and without electromagnetic forcing

This dissertation focuses on turbulent thermal convection, which occurs in a wide range of (geo)physical situations, like in the atmosphere, the oceans, the interior of stars or planets, and engineering applications, like metal casting or crystal growth processes. In this work, a special type of thermal convection, Rayleigh-Bénard convection, is...

Hydraulic roughness in sediment-laden flow

Most estuarine, and some coastal, areas are characterised by large amounts of fine-grained cohesive and non-cohesive sediments. At sufficiently high concentrations, sediment transport in suspension may significantly influence the hydrodynamics. In sediment-laden flow with concentrations of approximately, stratification may occur due to a...

Direct simulation and regularization modeling of turbulent thermal convection

This dissertation focuses on turbulent thermal convection, which occurs in a wide range of geophysical and engineering situations, such as the atmosphere, the sun, the earth's mantle, indoor climates etc. The first part of the thesis comprises a fundamental study of Rayleigh-BÉnard convection in a domain with aspect-ratio four. An ensemble of...