Mixed Convection Heat Transfer inside a Square Cavity Filled with Cu-water Nanofluid

In the present study, mixed convection heat transfer inside a square cavity filled with Cu-water nanofluid has been investigated numerically. The bottom wall of the cavity is maintained at a constant high temperature while the vertical sidewalls are assumed to be at a constant low temperature. The top wall of the cavity is insulated and moving at a constant velocity. Galerkin finite element method has been employed to solve the continuity, momentum and energy balance equations for the present problem. Analysis of thermal and flow fields inside the cavity has been analysed in terms of isotherms, streamlines and heatlines for a wide range of the Richardson number and solid volume fraction of the nanoparticle. Particular attention was paid to the case of pure mixed convection case with the Richardson No being equal to 1 for various combinations of natural convection and forced convection effects. The heat transfer performance of the system has been analysed in terms of average Nusselt number over the heated wall for various parameters. The present study shows that the distribution of streamline, isothermal lines and heatlines are very sensitive to Richardson number. The present study also shows that larger heat transfer rates can be achieved with nanofluid than the base fluid for all conditions. (C) 2015 The Authors. Published by Elsevier Ltd.