An experimental investigation of heat transfer and flow friction characteristics of louvered fin surfaces by the modified single blow technique

This paper describes the development of an experimental facility to determi ne the heat transfer and flow friction characteristics of heat exchange sur faces by the modified single blow technique and the application of this tra nsient technique to evaluate the performance characteristics of louvered fi n heat exchangers. The reliability of implementing the modified single blow technique on the developed test facility is borne out by the good agreemen t in the heat transfer and flow friction data for the parallel plate test c ore when compared with theoretical and empirical correlations available in the literature. Performance evaluation of two louvered fin surfaces used ma inly for cooling of large land and marine based electrical power generator sets is carried out and compared with similar louvered fin surfaces availab le in the literature. On the basis of dimensionless area and power factors, it was found that the flat fin is slightly superior in overall performance than its corrugated counterpart for low Reynolds numbers. Both surfaces ar e however inferior in performance when compared with the flat fin surface o f Achaichia and Cowell and the corrugated fin surface of Davenport. Use of the j/f ratio as an approximate figure of merit led to an inaccurate assess ment of the performance of the louvered fin heat exchanger surfaces evaluat ed in this study.