A new Non-wallis-type empirical correlation to predict the interfacial
friction factor in vertical annular pipes flow
Abstract
Accurate prediction of the interfacial friction factor is the basis to
calculate the pressure drop in annular pipe flow. Many previous
empirical correlations based on the superficial gas Reynolds number
perform not so well in condition with a high pressure or a large liquid
velocity. Analysis on the collected experimental data show that the
modified Weber number is better than the superficial gas Reynolds
number, at considering the effect of the liquid velocity and pressure on
the interfacial friction factors simultaneously. So a new correlation
was proposed based on the modified Weber number, the form of which is
different from that of wallis-type correlation. The new correlation
consider the effect of the gas velocity, gas density, liquid velocity
and liquid viscosity and pipe diameter. Evaluation against 414
experiment data show that the new correlation works better than any
other evaluated correlation with a mean absolute error of 17.77%.