マイクロバブルチャネル流の抵抗低減流動構造の強拡大PTV計測

抄録

The phenomenon of the drag reduction effect with microbubble has been studied experimentally. We revealed the drag reduction effect by using two types of bubbles which are generated in tap water and that with surfactant. We have approached by wall shear stress measurement and flow visualization by using Highly Magnifying PTV with telecentric lens. In both bubble flows, the experiments have been carried out with the Reynolds number ranging from 10 000 to 50 000 and void fraction up to 0.04. In condition of drag reduction effect observed, injecting bubble diameter was 0.6-1.3 mm and the ejection and sweep event were reduced by bubble injection and Reynolds stress was decreased.