Ellipsoidal protrusions for enhanced thermal performance in fin-tube heat exchangers

Abstract

Enhancing heat transfer in fin-tube heat exchangers is crucial for improving energy efficiency across various industrial applications. In this study, the effects of the position angle ( α ), attack angle ( β ), and size scale ( ε ) of ellipsoidal protrusions on the heat transfer characteristics of a fin-tube heat exchanger were numerically analyzed within the Reynolds number range of 1500–5000. Results showed that as α and ε increased, the vorticity generated downstream of the protrusions also increased. At α = 45°, heat transfer decreased as β increased, whereas at α = 67.5° and 90°, it increased with β . The Colburn j factor of fins with protrusions increased by 48.85 % compared to that of fins without protrusions at α = 90° and β = 40° with ε = 1.2. At α = 90°, both the Colburn j factor and the friction factor increased significantly; thus, the optimal position was identified as α = 67.5° and β = 40° with ε = 1.2, where the volume goodness factor was 25.41 % higher than that of fins without protrusions. These findings offer valuable insights for designing more efficient fin-tube heat exchangers, with implications for energy conservation in thermal management systems.