The Effects of an Enclosure Inclination Angle and its Walls Movement Direction on Variable Properties Nanofluid Mixed Convection

In this paper the effects of inclination angle and the direction of movement of moving walls of an enclosure on nanofluid mixed convection have been investigated for two different cases. In the first case natural and forced convection effects are in agreement, whereas in the second case they are opposed. Simulations have been performed for temperature dependent as well as temperature independent thermal conductivity and viscosity of water-Al2O3 nanofluid. The volume fractions of nanoparticles between 0 and 0.08 have been considered and the inclination angle of the cavity has been changed between 0 and 90°. To solve the governing equations the SIMPLE algorithm and a finite volume based method have been used. The results show by increasing the inclination angle, which enhances the forced convection, the three convective cells at low inclination angles change to one cell. The trend for change of average Nusselt number with increasing volume fraction is different for temperature independent cases compared to temperature dependent cases. Therefore, in order to obtain accurate results in numerical simulations, the temperature dependency of properties should be considered.