K-1214 界面活性剤水溶液の管内流遷移(S17-4 抵抗減少効果)(S17 非ニュートン流体の複雑流路内の流れ)

Abstract

This paper describes the LDV measurement of the generation and growth of the turbulent puff and slug in the transitional pipe flow of a surfactant (TTABr)-distilled water solution, the concentration of which was smaller than 400 ppm. The test pipe was a straight glass tube of 5.02 mm in inside diameter and 2576 mm in length. A large perturbation was introduced by a ring-shaped roughness element installed at a downstream location of 77D from the pipe entrance. In the straight pipe without the roughness element, while laminar flow is kept to 15300 under water flow, a quasi-laminar state at 2400<Re<11000 and the initiation of transition to turbulence at Re=11000 were clearly observed under 400 ppm solution. The result of the experiment with the roughness element showed that, as the concentration of the surfactant increases more than 260 ppm, the critical Reynolds number, in which the turbulent slug and puff begin to appear, increases and the growth rate of turbulent slug decreases.