Coupled velocity and temperature measurements in an air-filled differentially heated cavity at Ra=1.2E11

The experimental work described in this paper presents a turbulent natural convection flow at high Rayleigh number (RaH = 1.2 × 1011) within a 4 m-high differentially heated cavity filled with air. Synchronized measurements of velocity and temperature have been developed to describe the turbulent behavior of the flow. For this purpose, this coupled acquisition leads, among others, to the calculation of turbulent heat fluxes. These fluxes are provided in this paper and compared to other turbulent quantities (Reynolds stresses for instance). The synchronization of the acquisitions of velocity and temperature has been set up by the coupling of PIV and micro-thermocouple (Ø = 12.7 μm) measurements. Buoyant effects as well as velocity-temperature interactions on such a turbulent flow are discussed in this paper.