Effect of holes placed on the perforated finned heat exchanger at different angles on the Nusselt and Reynolds numbers

Abstract

In this research, 6mm diameter holes were opened on each circular fin on a heating tube in order to increase convective heat transfer. This is different from the other studies in the literature. These holes were placed on the circular fin in such a way as to follow each other at the same chosen angle. The holes created turbulence in a region near the heating tube surface on the bottom of the fin. Experiment were performed to analyze the effect of this turbulence on heat transfer and pressure drop. These experiment were performed at six different angular position in order to determine the best angular positioning. In addition, a perforated finned heater was compared with an imperforated finned heater to observe the differences. When Nud values were considered for the same airflow rate and the same Red, the Nud value of the heater with holes was found to be 2.43% higher than the Nud value of the heater without holes. However, there was a 3.84% decrease in pressure.