Flow Visualization in the Louvered Fin Heat Exchanger

Recently, louvered fin heat exchanger geometry is widely used in automotive radiators and air conditioners. However, the optimum combination of geometrical parameters, such as louver pitch, louver angle, and fin pitch, has not been clari-fied yet because of the complicated flow structure in fin arrays. In this study, flow visualization using the smoke wire method and measurement of pressure loss in the fin array were performed. Test section was a 5:1 scale model of an automotive radiator. Various patterns of fin array are examined by varying the Reyn-olds number from 390 to 1116. The results showed the possibility of higher heat transfer for a few patterns of fin array as com-pared with the conventional louvered fin array by causing the transition to turbulent flow at more upstream location in the fin array.