Natural convection of water-CuO nanofluid in a cavity with two pairs of heat source-sink

Natural convection in a two-dimensional square cavity filled with a water-CuO nanofluid is numerically studied. Two pairs of heat source-sink are considered to cover the entire length of the bottom wall of the cavity while the other walls are thermally insulated. The nanofluid is assumed to be homogenous and Newtonian. The governing differential equations are discretised by the control volume approach and the coupling between velocity and pressure is solved using the SIMPLE algorithm. A comparison study is presented between two cases with different arrangements of the two pairs on the bottom wall. The effects of Rayleigh number and solid volume fraction of the nanofluid on the heat transfer rate have also been examined. The results show that regardless of the position of the pairs of source-sink, the heat transfer rate increases with an increase of the Rayleigh number and the solid volume fraction. (C) 2011 Elsevier Ltd. All rights reserved.