Laminar Flow in Helical Coils: A Parametric Study

Abstract

In the present study, experimental observations on pressure drop measurements for fully developed, incompressible Newtonian fluid flowing through helical coils of constant circular cross section under laminar flow conditions are reported. To elucidate the effect of coil pitch and coil diameter on the friction factor, 5 types of coils with 12 different combinations of varying radii, such that 8.3 ≤ p/dt ≤ 66.7 and 11.7 ≤ Dc/dt ≤ 105.48, have been used. The experimental observations indicated that the Germano number (NGn) successfully signifies the combined effect of various coil parameters on the pressure drop. Hence, the data corresponding to low and high Germano numbers (NGn ≤ 70 and NGn > 70) have been treated separately, to yield suitable correlations for the laminar flow region. The correlations developed explain the present experimental data to within ±10% (in the range of 1 < NGn < 130) and the data available in the literature to within ±15%.