Generalized heat-transfer and fluid-flow correlations for corrugated louvered fins

We report heat-transfer and fluid-flow correlations to describe the performance of heat exchangers that use corrugated louvered fins. Friction factor f and Colburn factor j were investigated with respect to the ratio of the fin pitch to the louver pitch (Fp/Lp). Whereas previous correlations cannot be applied for Fp/Lp > 1, our f and j correlations can be utilized in a wide range of Fp/Lp which is not only to Fp/Lp < 1, but also to Fp/Lp > 1, for 100 < Re < 3000. We also derived flow efficiency η correlation which is applicable for 0.3 < Lp sin Lα/Fp < 0.7, where Lα is the louver angle, in 100 < Re < 3000 within an error of ±15%.