The University of Southampton
University of Southampton Institutional Repository

Statistical structure of momentum sources and sinks in the outer region of a turbulent boundary layer

Ganapathisubramani, B. (2008) Statistical structure of momentum sources and sinks in the outer region of a turbulent boundary layer Journal of Fluid Mechanics, 606, pp. 225-237. (doi:10.1017/S0022112008001675).

Record type: Article


The spatial structure of momentum sources and sinks (T > 0 and T < 0; where T is the streamwise component of the Lamb vector) is examined in a turbulent boundary layer by using dual-plane particle image velocimetry data obtained in streamwise–spanwise planes at two wall-normal locations (x2/? = 0.1 and 0.5, where x2 is the wall-normal location and ? is the boundary layer thickness). Two-point correlations of T indicate that the size of source motions remains relatively constant while the size of sink motions increases with increasing wall-normal distance. The relative strength of sink motions also increases away from the wall. The velocity field in the vicinity of source/sink motions was explored by computing cross-correlations of T with the velocity components. Source-like motions are correlated with elongated low-momentum zones that possess regions of upwash embedded within them and appear to be the strongest in areas where these low-momentum zones meander in the spanwise direction. Momentum sinks appear to be located within low-speed regions that are within larger high-momentum zones. The velocity fluctuations undergo rapid transitions between quadrants in the vicinity of sinks (i.e. both streamwise and wall-normal velocity fluctuations change sign). The length scales, over which the fluctuations change sign, are much larger at x2/? = 0.5 than at x2/? = 0.1.

PDF GANAPATHISUBRAMANI2008a.pdf - Version of Record
Restricted to Repository staff only
Download (277kB)

More information

Published date: 2008
Organisations: Aerodynamics & Flight Mechanics


Local EPrints ID: 187415
ISSN: 0022-1120
PURE UUID: b513e81b-30fd-42fa-aec3-1af97aaf6405
ORCID for B. Ganapathisubramani: ORCID iD

Catalogue record

Date deposited: 17 May 2011 09:37
Last modified: 18 Jul 2017 11:45

Export record


Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton:

ePrints Soton supports OAI 2.0 with a base URL of

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.