BOUNDARY-LAYER AND SCALING PROPERTIES IN TURBULENT THERMAL-CONVECTION

We describe an experiment which has been designed to measure both spat ial and temporal features of turbulent thermal convection in a fluid l ayer heated from below. Specifically we have studied the dependence of the heat flow vs. the Rayleigh number, the thermal boundary layer pro file, the temperature probability distribution function, the frequency and wave number power spectra. All the results have been compared wit h recent theories. The relevant scales of the problem, the Bolgiano an d dissipative lengths, are also computed as a function of control para meters.