An experimental study of flows and heat transfer enhancements in an air-filled differentially heated cavity of vertical aspect ratio 4, is presented. The control mechanism employed in the present research consists in thermal disturbances produced by a thin tube located at the bottom of the hot wall. The effects of amplitude and of temperature frequency signals are investigated for two Rayleigh numbers. For the first value, just above the first bifurcation, the flow is periodical. For the second, the flow is turbulent. The results show details of flow structures, such as the spatial distribution of the local mean and fluctuating velocity, the evolution of the global and local Nusselt numbers. A more complex behaviour of the flow is observed than was anticipated.

This content is only available via PDF.
You do not currently have access to this content.