Numerical Mixed Convection Heat Transfer Analysis in a Ventilated Irregular Enclosure Crossed by Cu-Water Nanofluid

The present paper reports a numerical investigation of steady and laminar mixed convection flow within an irregular ventilated enclosure, crossed by Cu-Water nanofluid. The bottom wall is maintained at a constant and uniform temperature, whereas the top and the vertical walls are adiabatic. The inclined wall as well as the nanofluid at the entrance is kept at a lower constant temperature. The governing coupled equations are resolved by the means of the finite volume technique. The computations are performed using a homemade computer code, which was successfully validated, after comparison of our results with pervious numerical and experimental works. Empirical relations to predict the nanofluid's effective thermal conductivity and viscosity were employed. The results are analyzed through dynamic and thermal fields with a particular attention to the Nusselt number evaluated along the active wall. The results reveal that the flow structure is more sensitive to both Richardson and Reynolds numbers variations. Moreover, heat transfer is enhanced by the increase in the nanoparticles volume fraction, Richardson and Reynolds numbers and by the decrease in the nanoparticles diameter. Useful correlations predicting the heat transfer rate as a function of nanoparticles volume fraction and diameter as well as the Richardson number are proposed.