2010 Fiscal Year Final Research Report

Study on drag reduction in turbulent boundary layer flow of heterogeneous surfactant solutions

Research Project

Project/Area Number	21760126
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Single-year Grants
Research Field	Fluid engineering
Research Institution	Nagoya Institute of Technology
Principal Investigator	TAMANO Shinji Nagoya Institute of Technology, 大学院・工学研究科, 助教 (40345947)
Project Period (FY)	2009 – 2010
Keywords	流体工学 / 抵抗低減 / 乱流境界層 / 界面活性剤
Research Abstract	In this study, first a slot injection system of surfactant solution was constructed. Next, the flow visualization and LDV measurements were performed in the flat-plate turbulent boundary layer flow with water or surfactant solution injection from the wall, in order to clarify the mechanism of drag reduction. It is found that in the case of surfactant solution injection, layered-structures parallel to the wall developed in the streamwise direction, and the wall-normal turbulence near the wall is strongly attenuated. Moreover, in both cases of homogeneous and heterogeneous (injected) surfactant solutions mean velocities scaled by the friction velocity are well arranged by the amount of the drag reduction, in which the mean velocity increases with the increase in the drag reduction ratio.

(5 results)