Abstract
A simultaneous measurement of velocity and thermal fields in the turbulent natural convection boundary layer in water has been conducted with a particle image velocimetry and a thermocouple rake. The measurement accuracy of turbulent heat fluxes was improved by compensating instantaneous velocity fluctuations with POD analysis. Because the maximum velocity for water becomes relatively larger than that for air, turbulent heat fluxes normalized with the maximum velocity and temperature difference made a marked difference between water and air. When turbulent heat fluxes are normalized with wall heat flux, both profiles for water and air are coincided with respect to one another. Therefore, it is recognized that characteristics of turbulent heat transfer essentially remain unchanged.
