Abstract
Drag reduction effect of surfactant solution is caused by SIS(Shear-induced structure). SIS is aggregation of the micelles in surfactant solution. In this study, we experimentally investigated drag-reducing flow using cationic surfactant. The SISs were visualized in turbulent flow to elucidate the induced mechanism and role of a micelle structure in drag reduction. The streamwise changes in the SISs and drag reduction were measured and their relationship was discussed. In our experiment we measured velocity properties and visualized inner flow in upstream and downstream, and there related the results.
