On the mixing length eddies and logarithmic mean velocity profile in wall turbulence
Loading...
View/Download File
Persistent link to this item
Statistics
View StatisticsJournal Title
Journal ISSN
Volume Title
Title
On the mixing length eddies and logarithmic mean velocity profile in wall turbulence
Published Date
2020-01-21
Publisher
Cambridge University Press
Type
Article
Abstract
Since the introduction of the logarithmic law of the wall more than 80 years ago, the equation for the mean velocity profile in turbulent boundary layers has been widely applied to model near-surface processes and parameterize surface drag. Yet the hypothetical turbulent eddies proposed in the original logarithmic law derivation and mixing length theory of Prandtl have never been conclusively linked to physical features in the flow. Here, we present evidence that suggests these eddies correspond to regions of coherent streamwise momentum known as uniform momentum zones (UMZs). The arrangement of UMZs results in a step-like shape for the instantaneous velocity profile, and the smooth mean profile results from the average UMZ properties, which are shown to scale with the friction velocity and wall-normal distance in the logarithmic region. These findings are confirmed across a wide range of Reynolds number and surface roughness conditions from the laboratory scale to the atmospheric surface layer.
Keywords
Description
Related to
Replaces
License
Collections
Series/Report Number
Funding information
Isbn identifier
Doi identifier
10.1017/jfm.2020.23
Previously Published Citation
Heisel, M., De Silva, C., Hutchins, N., Marusic, I., & Guala, M. (2020). On the mixing length eddies and logarithmic mean velocity profile in wall turbulence. Journal of Fluid Mechanics, 887, R1. doi:10.1017/jfm.2020.23
Suggested citation
Heisel, Michael; de Silva, Charitha M; Hutchins, Nicholas; Marusic, Ivan; Guala, Michele. (2020). On the mixing length eddies and logarithmic mean velocity profile in wall turbulence. Retrieved from the University Digital Conservancy, 10.1017/jfm.2020.23.
Content distributed via the University Digital Conservancy may be subject to additional license and use restrictions applied by the depositor. By using these files, users agree to the Terms of Use. Materials in the UDC may contain content that is disturbing and/or harmful. For more information, please see our statement on harmful content in digital repositories.