Investigating an additive drag reduction of turbulent flow in capillary tube

Abstract

    Turbulent drag reduction of surfactant counterion combinations was experimentally investigated ina capillary tube with diameter of 0.9 mm. The results showed that the drag reduction was existed inthe surfactant counterion combinations. The counterion concentration was influenced in the dragreduction ability of the combinations. The surfactant counterion combination 500ppm x20 showedthe drag reduction of 40% at the shear stress of 300 N/m2. In the experiment of capillary tube, thedrag reduction of water-nanotube solution (VGCFX-0.5%) was not achieved in the high shear flow.Its concentration and experimental conditions should be improved to get better in drag reduction.