抄録
The experiments on pressure drop in single-phase turbulent flow inside internally helical-grooved tube were carried out using fourteen different kinds of tube and a smooth tube with 6.35 mm outer diameter. The range of geometric parameters of test tube were number of grooves (45 to 65), helix angle (10 to 35 deg. ) and fm height (0. 15 to 0. 3 mm). In the experiments, the water was used as a test fluid and its inlet temperature was kept between 16 and 18 °C, and the flow rate was varied from 0.03 to 0.11 kg/s. The obtained data indicated that friction factor was increased with increasing the ratio of inner surface area of grooved tube to that of smooth tube and helix angle, while decreased with increasing the number of grooves. The correlations to predict the friction factor were developed based on the measured data, which predicted the experimental data within ± 10 % and correlated the data reported in literature within ± 10 %.
