Numerical investigation of water-alumina nanofluid natural convection heat transfer and entropy generation in a baffled L-shaped cavity

This article presents a numerical study of natural convection heat transfer and entropy generation of water alumina nanofluid in baffled L-shaped cavity. The left vertical and bottom walls are placed in hot and constant T-h temperature and the middle horizontal and right vertical walls are in cold and constant T-c temperature. The other walls are insulated. The baffle's temperature is T-c and their existence in cavity has a lot of impacts on flow behavior and it could disrupt flow order. The governing equations are solved numerically with Finite Volume Method using the SIMPLER algorithm simultaneously. The convection heat transfer results show: AR (aspect ratio) increasing enhances heat transfer. With dimensional ratio increasing, nanofluid has a greater impact on Nusselt growing. By baffle length increasing nanofluid has less impact on cooling cavity, as a result heat transfer raises. The entropy generation of mentioned parameters are also investigated and discussed. Finally, with studding the epsilon=S-m/Nu(m) (named thermal performance) the best AR and baffle length are introduced. (C) 2016 Published by Elsevier B.V.