界面活性剤水溶液の円管内流れの遷移(<小特集>抵抗減少効果とその応用)

抄録

Transition in pipe flow of drag reducing surfactant solution (C₁₄TABr) has been studied experimentally. Two stainless pipes with inside diameter of 3.03 mm and 2.04 mm are used and the measurements of pressure drop and pressure fluctuations are carried out. In the case of surfactant solution, turbulence appears at higher Reynolds number than that for water and the flow is stabilized. In contrast to the flow of polymer solution, critical Reynolds number for surfactant solution doesn't decrease even in the case of smooth inlet condition, except for the case of high concentration solution. With an increase in the concentration of solution, critical Reynolds number becomes to be unaffected by the pipe inlet conditions. When the surfactant solution is used, frequency of pressure fluctuation becomes higher and amplitude of it becomes less than that for water.