Thermo-Hydraulic Analysis of Slightly Inclined Finned Channel under Natural Convection

The influence of slight inclination, ‘α’ (i.e., ۱۰°, ۱۵°, and ۲۰°) of the channel comprised of shrouded vertical rectangular non-isothermal fin array has been computationally investigated. Simulations are performed to obtain the convective coefficient of heat transfer for the different dimensionless fin spacing (S*= ۰.۲, ۰.۳, ۰.۵), non-dimensional fin tip to shroud clearances (C*= ۰.۱, ۰.۲ and ۰.۳), Grashof numbers (Gr= ۱.۰۸×۱۰۵, ۴.۴۲×۱۰۵ and ۱۱.۵×۱۰۵), fin lengths (L= ۰.۲۵m and ۰.۵m) and fin heights (H= ۰.۰۲۵m, ۰.۰۴m, and ۰.۰۵۵m). Hydrodynamic behavior of the fluid indicates that a significant amount of flow reversal occurs near the entrance of the channel at very low inclination which vanishes with the increase in inclination. Further, at higher length, reverse flow is found to occur only in the clearance zone. An increase in the value of ‘α’ from ۱۰° to ۲۰°, results in enhancement of convective coefficient up to a maximum of ۱۶۱%. An increase in the value of fin spacing from ۰.۲ to ۰.۵ results in the enhancement of the convective heat transfer coefficient. At α= ۱۵° and ۲۰°, the heat transfer is enhanced by ۸۴.۱% and ۱۰۱.۶%, respectively, while at α=۱۰°, the same is reduced by ۳۳.۳%. At lower fin spacing (S*<۰.۳) increase in C* tends to reduce the efficiency. Further, the efficiency of the finite conductive fin is found to reduce by almost ۸% with an increase in Grashof number.

Keywords:

Grashof number , Inclination , Clearance , Convective coefficient , Fin efficiency