Heat transfer and airflow study of turbulent mixed convection in a ventilated cavity

摘要

The experimental and numerical results of the heat transfer and airflow by turbulent mixed convection in a ventilated cavity are presented. The experimental setup was built to use air as the heat transfer fluid. One vertical wall receives a uniform and constant heat flux, whereas the opposite wall is maintained at constant temperature. The remaining walls are thermally insulated. The experimental temperature profiles were obtained for different heat fluxes and air inlet velocities. Five different turbulence models were used to obtain the numerical results. The comparison between experimental and numerical temperatures indicates that the standard k-ε turbulence model presents a better agreement, with maximum percentage differences between 2.0% and 3.0%. The heat transfer coefficient had values between 2.2 and 3.4 W/m~2K, and it increases with the Rayleigh number and the Reynolds number. The experimental and numerical con-vective heat transfer coefficient predictions are closer for the higher Reynolds number (inlet air velocity of 0.5 m/s). The effects of varying the Rayleigh and Reynolds number on flow patterns and temperature fields were analyzed numerically.