On the incomplete similarity for turbulent velocity profiles in rough pipes


Journal Article

The possibility of extending Barenblatt's hypothesis of incomplete similarity for the velocity profile is analyzed for rough-pipe flows. The verification of this hypothesis, which leads to a power law in the intermediate region of the flow, is performed using Nikuradse's well-known data for pipes with homogeneous sand roughness. As detailed comparison between the log law and the power law would require much higher measurement resolution, no attempt is made here to assess the validity of one or the other law, and the power law profile is simply used as a working hypothesis. The power law fits well for a large part of the pipe section both for the transitionally rough regime and the fully rough regime. The coefficients of the power law show an interesting behavior as a function of the Reynolds number and the relative roughness. For the fully rough regime, it is possible to obtain simple expressions for the power law coefficients and the resistance law. © 2001 American Institute of Physics.

Full Text

Duke Authors

Cited Authors

  • Porporato, A; Sordo, S

Published Date

  • January 1, 2001

Published In

Volume / Issue

  • 13 / 9

Start / End Page

  • 2596 - 2601

International Standard Serial Number (ISSN)

  • 1070-6631

Digital Object Identifier (DOI)

  • 10.1063/1.1386939

Citation Source

  • Scopus