Effect of Al2O3/water Nanofluid on Conjugate Free Convection in a Baffle Attached Square Enclosure

A numerical study of conjugate free convection heat transfers of Al2O3/water nanofluid inside a differentially heated square enclosure with a baffle attached to its hot wall has been carried out. A detailed parametric study has been carried out to analyze the effect of Rayleigh number (10(4) <= Ra <= 10(6)), length, thickness and position of baffle, conductivity ratio and volume fraction of the nanoparticle (0 <= phi <= 0.2) on heat transfer. The thermal conductivity ratio of the baffle plays a major role on the conjugate heat transfer inside the enclosure. Higher the baffle length better is the effectiveness of the baffle. The average Nusselt number is found to be an increasing function of both thermal conductivity ratio and volume fraction of the nanofluid. The minimum enhancement of conjugate heat transfer is 30% when Al2O3/water nanofluid of 0.1 volume fraction is used for the entire range of Rayleigh number considered.