title: Intermittent nature of acceleration in near wall turbulence.
abstract: Using direct numerical simulation of a fully developed turbulent channel flow, we investigate the behavior of acceleration near a solid wall. We find that acceleration near the wall is highly intermittent and the intermittency is in large part associated with the near wall organized coherent turbulence structures. We also find that acceleration of large magnitude is mostly directed towards the rotation axis of the coherent vortical structures, indicating that the source of the intermittent acceleration is the rotational motion associated with the vortices that causes centripetal acceleration.
authors.affiliation: Department of Mechanical Engineering and Yonsei Center for Clean Technology, Yonsei University, 134 Shinchon-dong, Seodaemun-gu Seoul, 120-749, Korea. clee@yonsei.ac.kr
authors.forename: Changhoon
authors.initials: C
authors.lastname: Lee
authors.forename: Kyongmin
authors.initials: K
authors.lastname: Yeo
authors.forename: Jung-Il
authors.initials: JI
authors.lastname: Choi