Eddy viscosity and complete log-law for turbulent pipe flow at high Reynolds numbers

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Turbulent pipe flow velocity distribution at high Reynolds numbers is described by Coles' log-wake law for which the wake component is purely empirical. This research innovates Coles' wake law with another log-function, and thus combines the log- and the wake-laws into a single (complete) log-law, for which the von Kármán constant (0.39) is the only fit parameter. Specifically, the symmetrical velocity distribution about the centreline requires a symmetrical eddy viscosity model which is approximated by a quartic polynomial, leading to a complete log-law including the effects of the bottom and top walls as well as their interactions. The complete log-law is confirmed with data from both smooth and rough pipes; it also results in an accurate and explicit friction law for smooth pipe flow. Furthermore, the complete log-law is preliminarily tested with data from channels and boundary layers; the quartic eddy viscosity may be extended for ice-covered river flow in future studies.

Original languageEnglish (US)
Pages (from-to)27-39
Number of pages13
JournalJournal of Hydraulic Research
Volume55
Issue number1
DOIs
StatePublished - Jan 2 2017

Fingerprint

pipe flow
Pipe flow
turbulent flow
Reynolds number
eddy
viscosity
Viscosity
Velocity distribution
ice flow
river flow
Flow velocity
flow velocity
Ice
Boundary layers
friction
pipe
boundary layer
Rivers
Pipe
Polynomials

Keywords

  • Eddy viscosity
  • friction factor
  • log-law
  • pipe flow
  • velocity distribution
  • wall-bounded flow

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Water Science and Technology

Cite this

Eddy viscosity and complete log-law for turbulent pipe flow at high Reynolds numbers. / Guo, Junke.

In: Journal of Hydraulic Research, Vol. 55, No. 1, 02.01.2017, p. 27-39.

Research output: Contribution to journalArticle

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