Numerical simulation of natural convection in a square cavity utilizing nanofluid and subjected to air stream cooling

Abstract EN

In the present paper the natural convection in a square cavity utilizing Cu-water nanofluid is examined numerically.

The cavity is exposed to cooling air stream with free stream temperature (T∞) from left wall and its right and bottom walls kept with cold and hot temperatures (TC) and (TH) respectively, while the cavity top wall considered as adiabatic.

The nanofluid flow inside the cavity is assumed to be laminar and obeying to Boussinesq approximation.

The governing equations are solved by finite volume method using ANSYS FLUENT code.

The results are accomplished with a range of nanofluid volume fraction =0–0.16, Rayleigh number Ra=103–105 and free stream Reynolds number Re∞=103–104.

The effects of these variables are displayed on the stream function (), isotherms () contours and average Nusselt number (Nuavg).

The results show the heat transfer rate augmented with increasing , Ra and Re∞.

Also, the increment in both  and Ra increases the circulation inside the cavity while increasing Re∞ produces secondary vortices and reduces circulation at the main vortex of the cavity.

The results of local Nusselt number (Nu) and isotherms () are compared with other studies and show good agreement with maximum error values 14.28% and 3.2% respectively.