Influence of Non-uniform Heating Profiles on Free Convection Entropy Generation Inside an Enclosure Filled with Nanofluid

The scope of the present work is to explore the influence of non-uniform heating on entropy generation during free convection in an enclosure using Cu-water nanofluid. The numerical analysis is performed using the finite volume approach. The investigation is carried out in a two-dimensional framework. The non-uniform heating is implemented on the left wall considering parabolic, linearly increasing, and linearly decreasing profiles while the total power is kept constant. The right wall is maintained isothermally cold. Other walls of the enclosure are maintained adiabatic. The numerical simulation is carried out for the fixed value of the Rayleigh number and nanoparticle volume fraction. The details of the flow and heat transfer are studied using the streamlines and isotherms. The irreversibility due to the flow and heat transfer is studied using the contours of the entropy generation rate due to the thermal conduction and viscous dissipation. The results show that for all the cases investigated, the linearly increasing heating profile is most undesirable as the rate of entropy generation is maximum. On the other hand, the parabolic profile shows a minimum entropy generation and is suggested as a better heating profile.