界面活性剤水溶液噴流の拡散挙動に及ぼす溶液濃度の影響

抄録

It is well known that the reduction of turbulent friction by adding small amount of the surfactant. Because this method can attain the drag reduction rate up to 80 %, the mechanism of the drag reduction has been studied by many researchers to save the energy. However, there are few studies focused on the dispersion of surfactant solution. In this paper, the effect of surfactant on dispersion of liquid jet is investigated for various concentration. The cationic surfactant used in this study is CTAC and the counter-ion is NaSal at concentration of 30, 100, 200 and 300 ppm at the Reynolds number Re = 700, 1800 and 3500. The vertical concentration distributions of the time-averaged concentration are obtained by adding the uranine to the surfactant solution, showing that the width of jet dispersion is suppressed by surfactant. Moreover, as the surfactant concentration increases, the suppress effect becomes stronger. However, there are no differences at 100 ppm, 200 ppm and 300 ppm. This result indicates limit of the suppression effect. At the low Reynolds number, there is no suppression effect at any concentrations. It indicates that the Reynolds number is important factor to suppress the dispersion of the liquid jet as well as surfactant concentration.