Generalized correlation for friction loss in drag reducing polymer solutions

The definition of the pipe flow friction factor has been extended to include the effect of fluid viscoelastic properties on energy dissipation in turbulent tube flow. The resulting friction factor includes a characteristic fluid relaxation time, which can be determined directly from rheological measurements, and reduces to the usual Fanning friction factor for inelastic fluids. The use of this more general friction factor enables turbulent tube flow data for both fresh and shear degraded “concentrated” drag reducing polymer solutions of various concentrations in various tube sizes to be correlated by the usual f vs. NRe relation for Newtonian fluids in smooth tubes.