Boundary layer structure in confined turbulent thermal convection

Abstract

The structure of viscous and thermal boundary layers at the heated and cooled plates in turbulent thermally driven flows are of fundamental importance for heat transfer and its dependence on the thermal forcing (the Rayleigh number Ra in non-dimensional form). The paper by Shi, Emran & Schumacher (J. Fluid Mech., this issue, vol. 706, 2012, pp. 5-33) stresses the deviations of the boundary layer vertical profiles from the Prandtl-Blasius-Pohlhausen theory. Recent papers showing very similar results, in contrast, focus more on the similarities.

Boundary layer evolution in turbulent Rayleigh-Benard convection

“…When a gas or fluid in a cylindrical cell of height H and diameter D is cooled from above and heated from below turbulent convection is triggered provided that the temperature difference between top and bottom plates is sufficiently large. Crucial for the deeper understanding of the mechanisms of turbulent heat transport is the analysis of the physics in the tiny boundary layers at the top and bottom [1]. The video shows the dynamics of velocity field in the thermal boundary layer.…”

Boundary layers and wind in turbulent thermal convection

“…Note, the relation (8.44) holds for the Prandtl-Blasius boundary layer (m = 0) as well as for general Falkner-Skan boundary layers and is one of the main assumptions in the [50] theory on scaling in thermal convection for the case of non-turbulent boundary layers (see also [51,55,134]). Vertical profiles of the temperature and horizontal velocity near the horizontal plates are primary flow characteristics and their investigation is a part of any RBC study [3,33,47,56,104,111,122,135,136,140,145,149,173]. They are usually compared against the predictions for laminar boundary layers, based on the Prandtl-Blasius ansatz, which is a particular case of the more general Falkner-Skan approach.…”