Numerical study of natural convection in a partitioned cavity with partially heated and cooled walls containing nanofluid

The present study investigates numerically the natural convection of nanofluid in a square cavity with partially active sidewalls. The cavity is partitioned with a baffle attached to the middle of insulated bottom wall. The active part of the left sidewall is at a higher temperature than that of the active part of the right sidewall. The top, bottom and the remaining parts of the sidewalls are insulated. The governing equations are discretized using the control volume method. A proper upwinding scheme is employed to obtain stabilized solutions. Using the developed code, a parametric study is undertaken and the effects of the Rayleigh number, the locations of the active parts of the side walls, the volume fraction of the nanoparticles and the kind of the nanoparticles on the fluid flow and heat transfer inside the cavity are investigated. According to the numerical results, it has been observed that the average Nusselt number is decreased by partitioning the cavity and is increased by increasing the Rayleigh number and volume fraction of nanoparticles. In the cavity with baffle, the maximum average Nusselt numbers for the high and the low Rayleigh numbers occur in the bottom-top and the middle-middle configurations of the thermally active parts respectively, but the maximum average Nusselt number in the cavity without baffle for all Rayleigh numbers occurs in the middle-middle configuration. The heat transfer rate is low for the top-bottom thermally active locations.

کلیدواژه ها:

Nanofluid ، Natural convection ، Partiallyactive walls ، Partitioned cavity