Yoshimichi Hagiwara
Department of Mechanical and System Engineering, Graduate School of Science and Technology, Kyoto Institute of Technology Goshokaido-cho, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
Hidetoshi Hana
Dept. of Mechanical and System Eng., Kyoto Institute of Technology, Matsugasaki, Kyoto 606, Japan
Mitsuru Tanaka
Dept. of Mechanical and System Eng., Graduate School of Science and Technology, Kyoto Institute of Technology, Matsugasaki, Kyoto 606, Japan
Susumu Murai
Dept. of Mechanical and System Engineering Kyoto Institute of Technology Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
Direct numerical simulations have been conducted with many cluster models of beads and connecting springs in the buffer region of a turbulent channel flow in order to investigate how the low-speed streaks, the high-speed streaks and the flow related to the streaks are affected by the cluster models. The cluster model represents highly entangled polymers. The computational results show that the minor streaks and the small-scale eruptive flows associated with the low-speed streaks, whose length scale and time scale are comparable to those of the cluster model, are attenuated preferentially by the clusters.