Progress in pipe and channel flow turbulence, 1961–2011

Abstract

Although much progress has been made in pipe and channel flow turbulence over the past 50 years since the Turbulence Colloquium Marseille 1961 (TCM 1961), these simple wall-bounded turbulent flows have continuously baffled us, refusing to reveal their true and complete nature. In a broader sense, almost everything we thought we knew about wall-bounded turbulent flows, including the scaling laws that appear in textbooks, has been the subject of further scrutiny. An overview of the progress that has been made since TCM 1961 is presented, followed by discussions on unresolved issues that would require further investigations.

Keywords:

• pipe
• channel
• wall-bounded turbulent flows
• scaling laws
• turbulence structures

Acknowledgements

I am grateful to the organizing committee of TCM 2011 (Marie Farge, Keith Moffatt, Kai Schneider) for giving me the opportunity to present this review in spite of the fact that I have not been an active player for many topics discussed in the present paper. Discussions with Bill George, who seems to know all anecdotal histories, have been enlightening and entertaining.

Notes

^†This is a written version of the author’s presentation at Turbulence Colloquium Marseille, which was held in Marseille, France, during 26–30 September 2011 (hereinafter, TCM 2011). It served as an introduction to follow-up discussions on pipe and channel flow turbulence research, past, present, and future.

1. Strictly speaking, the streamwise direction in a fully-developed channel flow in all laboratory experiments is not homogeneous due to the side-wall boundary layers, whereas that in numerical simulations is treated as homogeneous. In this regard, the notion that future experiments and simulations should be focused on fully-developed pipe flows warrants special attention [1].