Characterization of a Mixed Convection Cell Designed for Phase Transition Studies in Moist Air

Abstract

A detailed description of an experimental set-up designed for upcoming investigations of latent and sensible heat transfer in a cuboid sample with air in- and outlets is given. The container is heated at the rear and cooled at the transparent front wall. Temperature measurements reveal that both sides exhibit a mean temperature deviation below 2% relative to the temperature difference between the mean plate temperature and the ambient temperature. This is a suitable temperature distribution for such measurements. Tomographic particle image velocimetry covering the entire volume of the mixed convection cell exhibits a large-scale circulation due to forced convection with a buoyancy-induced flow close to the temperature controlled surfaces. Forced convection origins from a flow between the inlet and the outlet channel with a mean deviation of 1% from the mean velocity and a maximum absolute deviation of 0.04 m/s. Measurements were performed for Reynolds numbers ranging from $300< \mathrm {Re} < 2000$ and Grashof numbers $\mathrm {Gr} < 1.2 \times 10^8$. A representative flow field obtained at $\mathrm {Re}=620$ and $\mathrm {Gr}=1.1\times 10^8$ is presented as an example.