Numerical Simulation of Natural Convection in a Square Cavity Utilizing Nanofluid and Subjected to Air Stream Cooling


In the present paper the natural convection in a squarecavity utilizing Cu-water nanofluid is examined numerically.The cavity is exposed to cooling air stream with free streamtemperature (T∞) from left wall and its right and bottom wallskept with cold and hot temperatures (TC) and (TH) respectively,while the cavity top wall considered as adiabatic. The nanofluidflow inside the cavity is assumed to be laminar and obeying toBoussinesq approximation. The governing equations are solvedby finite volume method using ANSYS FLUENT code. Theresults are accomplished with a range of nanofluid volumefraction =0–0.16, Rayleigh number Ra=103–105 and freestream Reynolds number Re∞=103–104. The effects of thesevariables are displayed on the stream function (), isotherms ()contours and average Nusselt number (Nuavg). The results showthe heat transfer rate augmented with increasing , Ra and Re∞.Also, the increment in both  and Ra increases the circulationinside the cavity while increasing Re∞ produces secondaryvortices and reduces circulation at the main vortex of the cavity.The results of local Nusselt number (Nu) and isotherms () arecompared with other studies and show good agreement withmaximum error values 14.28% and 3.2% respectively.