Effects of Geometrical Parameters on Thermal-Hydraulic performance of air flowing in Additively Manufacturable Heat Exchanger

An additively manufactured airfoil finned plate-fin heat exchanger (PFHE) is proposed to be applied to a flue gas waste heat recovery system. This study numerically investigates the effect of various geometrical characteristics of the airfoil finned channel on the pressure drop and heat transfer using OpenFOAM with dry air as a working cold fluid. The studied parameters include the offset number (ξf), longitudinal number (ξl), transverse number (ξt), and fin height (hf) of the airfoil. Additionally, the effect of the fin number on the thermal-hydraulic characteristics of the flow channel is also studied to determine the minimum number of fins where the friction factor and Colburn j-factor variation along the flow length is nearly stabilized. The results of the study show that the 20 number of fins is reasonable for assessing the heat exchanger performance. The offset number has an influence on pressure drop and heat transfer until the offset length approaches the fin length, after which it has no effect. The longitudinal number effect on heat transfer per unit area and pressure drop per unit length is a linear variation, while the transverse number and fin height effect is a non-linear variation.