Abstract
Recently, by analyzing the measurement data of Nikuradze [NACA Tech. Memo No. 1292 (1950)], it has been proposed [N. Goldenfeld, Phys. Rev. Lett. 96, 044503 (2006)] that the friction factor, , of rough-pipe flow obeys a scaling law in the turbulent regime. Here, we provide a phenomenological scaling argument to explain this law and demonstrate how intermittency modifies the scaling form, thereby relating to the intermittency exponent, . By statistically analyzing the measurement data of , we infer a satisfactory estimate for , the inclusion of which is shown to improve the data-collapse curve. This provides empirical evidence for intermittency other than the direct measurement of velocity fluctuations.
- Received 23 February 2008
DOI:https://doi.org/10.1103/PhysRevE.77.055304
©2008 American Physical Society