Experimental study and numerical models assessment of turbulent mixed convection heat transfer in a vertical open cavity

摘要

Flow and heat transfer in a vertical open cavity with turbulent mixed convection is investigated experimentally and numerically. The internal size of the cavity is 1 m x 1 m x 1.2 m, with liquid nitrogen as the cold source and mica electronic heating plates as the heat source of the experiments. The velocity and temperature fields are obtained by hot-wire anemometry, particle image velocimetry and local temperature sensors for 4.6 x 10(4) <= Re <= 5.9 x 10(4) and Gr <= 1.8 x 10(13). The secondary upward flow was found to occur near the heated walls. Three two-equation RANS turbulence models, RNG k-epsilon model, L-B Low Re k-epsilon model and SST k-omega model, are used in the numerical simulation with the same boundary conditions as experiments. Through comparison with experimental data, Low Re k-epsilon model performs overall the best in the accuracy in solving mixed convection problems in large-scale vertical cavities with strong buoyancy force. (C) 2017 Elsevier Ltd. All rights reserved.