Experimental investigation and computational modelling of thermal boundary layers in turbulent natural convection (English shop)

Preview

Table of Contents, PDF (71 KB)
Extract, PDF (180 KB)

This work addresses the numerical and experimental modelling of turbulent, thermally driven air flows in various test configurations. These so-called convective flows represent one of the fundamental problems of fluid mechanics. They attract considerable scientific interest, since they play an essential role in many fields, such as meteorology or industrial applications. An understanding of these flows is particularly important against the background of atmospheric convective flows, which are influenced by a Coriolis force arising from the Earth’s rotation and can develop into cyclonic storms. In each individual test configuration, the convective flow is always generated between two opposing, isothermally heated walls. In addition to validating the chosen numerical model of a Large Eddy Simulation (LES), the results obtained in this work provide insight into the flow dynamics, the turbulence structures that develop, and the heat transfer in the respective test configuration. The focus here lies above all on resolving the thermal wall boundary layer. Of particular note is the numerical as well as experimental investigation of a so-called Rayleigh–Bénard problem subject to an additionally acting Coriolis force. The experiment realised for this purpose in a large centrifuge and the associated numerical study provide insight into the effect of the additional relative accelerations on turbulence production and heat transfer within the fluid.