Detlef Lohse is Professor and Chair of the Physics of Fluids group at the University of Twente, The Netherlands. His research focuses on multiphase flow from an experimental and theoretical perspective with research addressing microscopic as well as macroscopic scales.
Turbulent Rayleigh-Benard and Taylor-Couette flow
Rayleigh-Benard flow — the flow in a box heated from below and cooled from above — and Taylor-Couette flow -- the flow between two coaxial co- or counter-rotating cylinders -- are the two paradigmatic systems in physics of fluids and many new concepts have been tested with them. They are mathematically well described, namely by the Navier-Stokes equations and the respective boundary conditions.
While the low Reynolds number regime (i.e., weakly driven systems) has been very well explored in the '80s and '90s of the last century, in the fully turbulent regime major research activity only developed in the last decade. This was also possible thanks to the advancement of computational power and improved algorithms and nowadays numerical simulations of such systems can even be done in the so-called ultimate regime of turbulence, in which even the boundary layers become turbulent. In this talk we review this recent progress in our understanding of fully developed Rayleigh-Benard and Taylor-Couette turbulence, from the experimental, theoretical, and numerical point of view. We will explain the parameter dependences of the global transport properties of the flow and the local flow organisation, including velocity profiles and boundary layers, which are closely connected to the global properties. Next, we will discuss transitions between different (turbulent) flow states.
This is joint work with many colleagues over the years, and I in particular would like to name Siegfried Grossmann, Roberto Verzicco, Richard Stevens, Erwin van der Poel, and Rodolfo Ostilla-Monico.