Enhancement of heat transfer characteristics using aerofoil fin over square and circular fins

Abstract

The thermal conductivity of fin material, its geometrical profile and the mode of heat transfer etc, are the key factors which generally affects the heat transfer from fins. The present research deals with the improvement in heat transfer characteristics and the investigation of fin performance efficiency by using fins of varying geometrical profiles in pin fin apparatus. In this study the heat transfer characteristics inside a rectangular duct with circular, square and aerofoil geometrical profiles of fins were analyzed experimentally. The intention of the present work is to evaluate the heat transfer coefficient, Reynolds number, Nusselt number, pressure drop and efficiency of fin with circular, square and aerofoil geometrical profiles and all the results obtained will be compared with those from a circular fin of same material surface. In the present study, experimental results of the heat transfer characteristics of all the three geometrical profiles of fins under constant heat flux conditions are presented. Experiments are performed at various Reynolds numbers in the range of 1000–9000 and heat fluxes in the range of 0.91–3.64 kW/m2. The predicted results are validated by comparing with measured data. The predicted results are in reasonable agreement with the experiments. It is found that with increase in Reynolds number, the Nusselt number and thermal performance increases, for a fin having aerofoil profile as compared with a fin with square and circular profile. These are because of delayed separation of air and increase in contact time for a fin having aerofoil profile as compared with a fin with square and circular profile.