Convection - Experiments
Thermal convection is one of the most important heat transport mechanism and as such plays a crucial role in many geo- and astrophysical systems. We study experimentally different aspects of thermal convection using the Rayleigh-Bénard (RB) setup, where a fluid layer of height L, is confined by a warm plate from below and a cold one from above.
A schematic of a cylindrical RB cell is depicted in figure 1. When the temperature difference Δ between the plates is large enough, the fluid enclosed by the cylinder will start to transport heat by buoyancy induced convection in addition to conduction. The temperature difference can be expressed in non-dimensional form by the Rayleigh number Ra and is a measure of the system's driving strength. Likewise, the resulting heat flux that passes through the plates and the fluid can be expressed by the non-dimensional Nusselt number Nu . One important question is the dependence of Nu(Ra) .