Numerical investigation of natural convection heat transfer of nanofluids in a Γ shaped cavity

This paper analyzes the heat transfer and fluid flow of natural convection in a Gamma shaped enclosure filled with Al2O3/Water nanofluid that operates under differentially heated walls. The Navier-Stokes and energy equations are solved numerically. Heat transfer and fluid flow are examined for parameters of non-uniform nanoparticle size, mean nanoparticle diameter, nanoparticle volume fraction. Grashof number and different geometry of enclosure. Finite volume method is used for discretizating positional expressions, and the forth order Rung-Kuta is used for discretizating time expressions. Also an artificial compressibility technique was applied to couple continuity to momentum equations. Results indicate that using nanofluid causes an increase in the heat transfer and the Nusselt number so that for R = 0.001 in Cr = 10(3), the Nusselt number 25%, in Cr = 10(4) 26%, and in Cr = 10(5) 28% increases. Furthermore; by decreasing the mean diameters of nanoparticles. Nusselt number increases. By increasing R parameter (d(p,min)/d(p,max)) and nano particle volume fraction, Nusselt number increases. (C) 2012 Elsevier Ltd. All rights reserved.