1985 Volume 11 Issue 3 Pages 286-292
Water film was formed along smooth vertical tubes of various diameters and 800 mm in effective length, and the holdup was measured by a balanced lever. The model of Hanratty et al., based on a concept of boundary layer and mixing length, was modified to correlate the measured data by taking into account the effect of waves in the laminar region. A suggested equation showed good agreement with experimental data over a wide range of Reynoldsnumber, namely 24-6300.
The shearing force at the wall was measured by an electrochemical method. The friction coefficient obtained from the experimental data indicated clear critical points at both ends of the transition zone (from Re≅170 to Re≅900).
Wave characteristics were measured by a conductance method with a 10-mm electrode. Wave velocity was determined from cross correlation function. Wave thickness was statistically analyzed and it was found that with increasing Reynolds number the frequency curves tend to be flat and unsymmetrical.
