A techno-economic investigation of 2D and 3D configurations of fins and their effects on heat sink efficiency of MHD hybrid nanofluid with slip and non-slip flow

Abstract

The mixed convection heat transfer (MCHT) as a combination of forced and natural convection is studied in this paper. A rectangular enclosure with heatsink is considered that is filled with a hybrid nanofluids (HNFs). The assumed magnetic field (MF) applied the Lorentz force to the enclosure with heatsink. For the enclosure with heatsink, the boundary conditions are assumed as moving upper wall and lower wall with high temperature; Other both walls are well insulated to avoid heat transfer (HT) from them. There was a heat sink on the lower wall with the same temperature of the wall. The Flow could slip over the moving wall, and the non-slip boundary condition is violated on this wall. The governing equations of fluid flow and boundary conditions are discretized using the control volume formulation of the finite difference method and SIMPLE algorithm is used to solve the coupled equations. The effects of fin's length and different types of heat sinks with various lengths on the entropy generation rate (EGR) and Nusselt number (Nu) are investigated at different Richardson numbers (Ri) considering slip and non-slip conditions. The results showed that the HT and EGR increase by increasing the height of the fins. When the length of the heatsink blades was 1, it had the lowest manufacturing cost and at the same time the highest heat transfer per unit blade length, and economically, it was the most economical mode of the heatsink among the various models. The Nu and EGR are decreased using the slip boundary condition. Based on the results, The Nu per length reaches the maximum value for the lowest length of fin.