2325 円管を流れる界面活性剤水溶液のレイノルズせん断応力(S42-5 複雑流体の流動現象(5),S42 複雑流体の流動現象)  [in Japanese] 2325 Reynolds Shear Stress of Surfactant Solution Flowing in a Circular Pipe  [in Japanese]

Reynolds shear stress of surfactant solution flowing in a circular pipe was investigated experimentally by means of Laser Doppler anemometery. Concentrations of surfactant solution were 0, 28, 50, 100 ppm, and Reynolds numbers based on a bulk velocity, viscosity of water and a pipe diameter were set to 20000, 40000, 60000. Results show that the extreme suppression of Reynolds shear stress compared to water was occurred in the case of surfactant solution, and this was achieved by counteractions between outward interaction and ejection, inward interaction and sweep, respectively. The shear viscosity calculated from mean velocity distribution and previous results of rheometer test shows that there is a low viscosity region below the region which is in a shear induced state. This region makes a difference in streamwise velocity fluctuation between the cases of upward and downward fluid motion.