J0550302 抵抗低減界面活性剤水溶液の円管流れにおけるミセル構造と乱流遷移の関係

Abstract

In general, the drag-reducing effect in a pipe by a surfactant additive is attributed to rod-like micelles in the surfactant solution. This paper describes the results of experiments performed for determining the relationship between the micelle structure in the surfactant solution and the drag-reducing effect in a pipe flow. The experimental apparatus is circulation type by using pump and inner diameter of test pipe is 10.6mm. A fluorescence probe method was used to examine the micelle structure in the drag-reducing surfactant solution flow. Pyrene-1-carboxaldehyde was used as the fluorescence probe. The obtained experimental results were as follows. When the drag-reducing surfactant solution was irradiated with ultraviolet light, the fluorescence intensity at the wavelength of 487nm varied with the micelle structure. The fluorescence intensity decreased with the generation of the Shear Induced Structure (SIS) and increased with the disappearance of the SIS. The fluorescence intensity near the pipe wall increased simultaneously with the flow transitions to turbulence. In other words, the turbulent transition occurs along with the disappearance of the SIS near the wall.