EPJ E – Turbulent convection at the core of fluid dynamics

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Published on 10 August 2012

Buoyant convection of a fluid subjected to thermal differences is a classical problem in fluid dynamics. Its importance is compounded by its relevance to many natural and technological phenomena. For example, in the Earth atmosphere, the study of thermal convection allows us to do weather forecasts and, on larger time and length-scales, climate calculations. In the oceans, where there are differences in temperature and salinity, turbulent convection drives deep-water currents. Geology and astrophysics are other areas where thermal convection has great impact. The simplest and most useful convection systems is the Rayleigh-Bénard setup: a fluid in a container heated from below and cooled from above. In this classical system, the flow properties are determined by the scale and geometry of the container, the material properties of the fluid, and the temperature difference between top and bottom. The crux of the problem is to how to determine the rate of heat transfer in a given condition.

In this EPJE Colloquium paper, Francesca Chilla’ and Joerg Schumacher review the recent experimental, numerical and theoretical advances in turbulent Rayleigh-Bénard convection. Particular emphasis is given to the physics and structure of the thermal and velocity boundary layers, which play a crucial role in governing the turbulent transport of heat and momentum in highly turbulent regimes. The authors moreover discuss some important extensions of Rayleigh-Bénard convection, such as the so-called non-Oberbeck-Boussinesq effects and address convection with phase changes.