Numerical study and geometrical investigation of the position of alternated fins mounted in channels subjected to forced convective flows

Abstract

The present numerical study aims to investigate the geometry of an arrangement of isothermal rectangular fins, mounted in alternating form in the lower and upper surfaces of microchannels, subjected to laminar, incompressible, and forced convective flows in a two-dimensional domain. The main purpose is maximizing the efficiency and the heat transfer rate among the fins and the fresh flow in the channel, and minimizing the pressure drop in the finned channel. It is investigated here one degree of freedom (L1/L) that represents the distance between the first and second fins of the arrangement. The remaining degrees of freedom are kept constant (L2/L and L3/L). All numerical simulations were performed considering air as a working fluid for Reynolds and Prandtl numbers of ReH = 100 and Pr = 0.71. The best thermal performance of the arrangement was achieved for the extreme ratios of L1/L, i.e., when the second fin was mounted near the first or third fins. A small advantage is noticed for the lowest magnitude of L1/L in comparison with the other extreme position. The difference between the best and worst thermal performance, measured by the heat transfer rate, was nearly 23%. For the pressure drop, an intermediate ratio L1/L = 0.4 was conducted to get the best fluid dynamic performance.