Abstract
The present study proposed a dimpled louver fin made by adding dimpled slots between the fin base and the brazing line of the flat tube to reduce flow resistance and enhance drainability. Numerical simulations were conducted on the conjugated heat transfer of louver fin geometries using the commercial CFD code. Drainability was tested for four enlarged plastic models made by a rapid prototype machine. The airflow pressure drop coefficient of the dimpled louver fin was 14% less than that of the baseline louver fin, the advantage increasing at low air velocity. The dimpled louver fin performed up to 5% better than the baseline fin in the performance index of the heat transfer capability per unit temperature potential for the same fan power. The dimpled louver fin drained water substantially up to 20% better than the baseline fin in the dip test.
Keywords: heat exchanger, louver fin, heat transfer, pressure drop, drainability