Experimental and numerical study of turbulent natural convection in an open cubic cavity

Study of natural convection in an open cubic cavity with side length of 1 m is presented. The experimental setup was built with the air as the heat transfer fluid. The vertical wall opposite to the aperture is subjected to uniform heat flux condition with the four different heat flux values in the range 55–333 W/m², whereas the remaining walls were kept thermally insulated. The temperature at discrete locations inside the cavity was obtained which followed evaluation of heat transfer coefficient and Rayleigh number. The thermal and flow analysis in 3-D was based on the standard k–ε turbulence model and implemented using CFD software Fluent 6.3. The spatial distribution for temperature, velocity and turbulent viscosity are determined and analyzed in the perspective of experimental observations. The experimentally determined ranges of Rayleigh number, Nusselt number and heat transfer coefficient are 1.66 × 10¹¹–7.1 × 10¹¹, 185.94–243.31 and 4.88–6.83 W/m² K, respectively. The observed maximum difference between the experimental and numerical values for heat transfer coefficient and Nusselt number are 10.8 and 14 % respectively.