Flow and heat transfer correlations for porous fin in a plate-fin heat exchanger

The present experimental study investigates the impact of porous fins on the pressure drop and heat transfer characteristics in plate-fin heat exchangers. Systematic experiments have been carried out in a simplified model of a plate-porous fin heat exchanger at a controlled test environment. The porous fins are made of 6101 aluminum-alloy foam materials with different permeabilities and porosities. Comparison of performance between the porous fins and the conventional louvered fins has been made. The experimental results indicate that friction and heat transfer rate are significantly affected by permeability as well as porosity of the porous fin. The porous fins used in the present study show similar thermal performance to the conventional louvered fin. However, the louvered fin shows a little better performance in terms of pressure drop. For compactness of the heat exchanger, the porous fins with high pore density and low porosity are preferable. Useful correlations for the friction factor and the modified j-factor are also given for the design of a plate-porous fin heat exchanger.