Effect of the Aspect Ratio on the heat transfer enhancement by the Al2O3-H2O Nanofluid traversing a Heated Shallow Cavity

Abstract

In this work, the effects of the cavity aspect ratio (AR) on the flow of Al2O3-water nanofluid in a two-dimensional cavity subjected on its lower part to a constant and uniform temperature. The governing equations are discretized by the finite volume method based one point closure turbulence model. For nanofluid proprieties, Maxwell-Garnetts model (MG) and Brinkman models are used for the calculation respectively of the conductivity and viscosity of the nanofluid. The parameters of this study are the shape parameter of the cavity from 2 to 14, Reynolds number Re between 4.103 and 105 and volume fraction of the nanoparticles between 0 and φ=4%. The cavity aspect ratio effect on the flow structure and heat transfer was also examined. The results confirm that the flow structure and heat transfer are very sensitive to the cavity aspect ratio. The numerical results highlight the effect of the main parameters on the distribution of Nusselt number and friction coefficient.