Effect of a discrete heat source location on entropy generation in mixed convective cooling of a nanofluid inside the ventilated cavity

Abstract

In this paper, the effect of localised heat sources on entropy generation owing to mixed convection flow in a vented square cavity has been studied numerically. Laminar steady forced convection flow of copper–water nanofluid through the cavity has been affected by density variations as a result of heat input from a wall–mounted heat source. To investigate the effect of the heat source location, three different placement configurations of the heat source have been considered. Furthermore, to further generalise the results, three different non–uniform heat flux conditions were also examined. The entropy generation rate has been analysed for Richardson numbers 0 ≤ Ri ≤ 10 and for solid volume fraction within 0 ≤ φ ≤ 0.05. With either uniform or non–uniform wall heating, the entropy generation rate is found to be minimal when the heat source and cavity exit are on the same wall. The maximum heat transfer rate, however, corresponds to the case when the main flow is parallel to the heated wall.