Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : November 12, 2022 - November 13, 2022
We have performed PIV measurements for the drag-reducing turbulent boundary layer flows by injecting surfactant aqueous solution. For the case of the high drag reduction ratio, large-scale turbulence structures were often observed in the fluctuating velocity field. However, the interaction between large-scale turbulence structures and wall-shear stress has not been investigated. In this study, we performed wide-range and high-magnification PIV measurements in order to obtain large-scale turbulence structures and wall-shear stress simultaneously. Decreasing and increasing of wall-shear stress correspond to passing turbulence structures which consist of low and high fluctuation velocities, respectively. This indicates that there would be the correlation between large-scale turbulence structures and instantaneous wall shear stress.
