Turbulent Friction Factor for Two-Phase: Air-Viscoelastic Fluid Flows Through Horizontal Straight Circular Tubes

Fully developed turbulent isothermal Fanning friction factors for air-viscoelastic fluid flows through a horizontal pipe were experimentally measured. The viscoelastic fluids studied were aqueous solutions of polyacrylamide at three different concentrations (100, 200, and 500 wppm). The two-phase friction factor data were correlated in terms of the apparent Reynolds number defined based on the effective viscosity for gas-liquid mixture. Over a range of the apparent Reynolds number from 10⁴ to 10⁵, the simpler homogeneous model used was found to be accurate enough for engineering prediction of friction factor for air-viscoelastic fluid flows through straight pipes. A correlation for the prediction of air-viscoelastic two-phase turbulent friction factor is proposed.