Friction factor correlation and pressure loss of single-phase flow inside herringbone microfin tubes.

Pressure drop of single-phase turbulent flow inside herringbone microfin tubes of different fin dimensions has been measured experimentally to develop a general correlation of single-phase friction factor for the herringbone tubes. Water has been used as a working fluid and the mass flow rate has been varied from 0.03 to 0.2 kg/s. Comparison of experimental data of the herringbone microfin tubes with those of helical microfin and smooth tubes shows that pressure drop of the herringbone tube is significantly higher than the helical and smooth tubes depending on the fin geometric parameters and mass velocity of the working fluid. Through semi-analytical approach and using these experimental data, a new correlation of single-phase friction factor for the herringbone microfin tubes has been proposed incorporating the effects of fin geometric parameters. The proposed correlation can predict the experimental data within plus or minus 10%.