An experimental study on friction reducing polymers in turbulent pipe flow

An experimental study was conducted to search the reduction of friction in fully developed turbulent pipe flow using different types of polyacrylamides as friction reducing polymers. Pressure drop measurements determined the friction reduction. Three different polymer types Superfloc A110, Superfloc A130 and Superfloc A150 were used to examine the effect of polymer concentration, Reynolds number and polymer type on friction reduction. The Darcy friction factor was obtained for each polymer type at the polymer concentration ranging from 0 to 500 wppm and a Reynolds number range of 10000-80000. It was observed that friction factor decreased with increment in polymer concentration and Reynolds number for each polymer. Higher molecular weight polymers are more effective at reducing friction. With increasing concentration of polymer, the measured data approaches the Virk asymptote, which represents the maximum friction reduction limit by the polymers. The percentage of friction reduction increased with increasing concentration of polymer up to 100 wppm for each polymer type and then began to decrease for polymer concentrations higher than 100 wppm. An empirical formula was obtained to calculate the Darcy friction factor as a function of Reynolds number and polymer concentration for Superfloc A110.