Session Ch - Convection & Buoyancy.
ORAL session, Sunday, November 23
308, Moscone Center
We report experimental results for turbulent rotating Rayleigh-Bénard convection in water with Prandtl number \sigma \approx 6. Heat transport measurements and flow visualization for Rayleigh number, 5\times 10^7\leq R\leq 5\times 10^8 and dimensionless rotation rates, 0 < Ømega < 8\times 10^4 are compared to obtain a consistent picture of turbulent boundary layer stability and the mechanisms for the enhancement of heat transport by rotation. The flow diagnostics consist of thermochromic-liquid-crystal visualization for the temperature field and PIV for the velocity field. A scanning PIV system allows us to measure the horizontal velocity field over a vertical distance of 3 cm below the upper cold boundary. The structure of the vortical plumes erupting from the boundary layer was determined to be cyclonic with Ekman suction at the core and Ekman pumping along a ring. No evidence for large scale circulation was found for strongly rotating convection.
\hfil Present Address: Jet Propulsion Lab, Pasadena, CA