Air side performance of a novel lanced fin and flat tube heat exchanger

A total of nine cross-flow heat exchangers having a novel lanced fin and a flat tube were studied experimentally. A series of tests were conducted for the air side Reynolds number based on the lanced fin hydraulic diameter in the range of 800 to 6500 with different fin spaces and fin lengths, at a constant tube-side water flow rate of 2.8 m(3)/h. The air side thermal performance data were analyzed using the effectiveness-NTU method. The characteristics of heat transfer and pressure drop for different geometric parameters were reported in terms of the Colburn j-factor and the Fanning friction factor f, as a function of Re. The effects of fin spaces and fin lengths on heat transfer and pressure drop were examined. The general correlations for j and f factors were derived by multiple linear regression analysis and F test of significance. The correlations for j and f factors can predict 95% of the experimental data within +/- 10%. Further, two comparison methods were adopted to evaluate on the whole the air side thermal hydraulic performance of the novel lanced fins.