Air side performance of brazed aluminum heat exchangers

Extensive experiments on the heat transfer and pressure drop characteristics of brazed aluminum heat exchangers were carried out. In the present study, 27 samples of louvered fin heat exchangers with different geometrical parameters, including tube width, louver length, louver pitch, fin height, and fin pitch were tested in an induced draft open wind tunnel. Results are presented as plots of friction factor, f, and Colburn j factor against Reynolds number based on louver pitch in the range of 100 to 1000. Comparisons between the Sahnoun and Webb model and the present test data are reported and good agreements were found. By introducing ''area ratio'' parameters, a simpler correlation of the Colburn j factor and friction factor f were obtained. It is shown thar 85% of the experimental data of heat transfer and friction data were correlated within +/-10%.