Speckle measurements of convection in a liquid cooled from above.
01 January 1988
The buoyancy driven recirculation in a liquid filled cavity cooled from above is locally modulated by an unstable thermal sublayer at the top surface. Quasi-steady measurements of the two-dimensional velocity distribution around the undulating central plume which descends through the upper liquid layers were made using multi-exposure laser speckle velocimetry, while the temporal fluctuations were monitored by shearing interferometry. Imposition of a fixed boundary over 50% of the upper surface had no observable influence on the flow field/plume in the liquid below it.