We are inviting IDEALS users, both people looking for materials in IDEALS and those who want to deposit their work, to give us feedback on improving this service through an interview. Participants will receive a $20 VISA gift card. Please sign up via webform.

Files in this item

FilesDescriptionFormat

application/pdf

application/pdfNatrajanWuChristensen.pdf (747kB)
PDF

Description

Title:Spatial signatures of retrograde spanwise vortices in wall turbulence
Author(s):Natrajan, Vinay K.; Wu, Yanhua; Christensen, Kenneth T.
Subject(s):Vortices
Wall turbulence
Abstract:The spatial signatures of retrograde spanwise vortices in wall turbulence are assessed from particle-image velocimetry measurements in the streamwise–wall-normal plane of a zero-pressure-gradient turbulent boundary layer at Reτ ≡u∗δ/ν =2350. The present results suggest that a proportion of retrograde spanwise vortices have a welldefined spatial relationship with neighbouring prograde vortices. Two-point crosscorrelations and conditionally averaged velocity fields given a retrograde vortex reveal that such structures are typically oriented either upstream of and below or downstream of and above a prograde core. While these pairings are consistent with the typical-eddy patterns reported by Falco and co-workers, we offer an alternative interpretation for a proportion of these retrograde/prograde pairs. In particular, the arrangement of a retrograde spanwise vortex upstream of and below a prograde core is also consistent with the spatial signature revealed if an omega-shaped hairpin structure were sliced through its shoulder region by a fixed streamwise–wall-normal measurement plane.
Issue Date:2007
Publisher:Cambridge University Press
Citation Info:V.K. Natrajan, Y. Wu, and K.T. Christensen. 2007. Spatial signatures of retrograde spanwise vortices in wall turbulence. Journal of Fluid Mechanics. 574: 155–167.
Genre:Article
Type:Text
Language:English
URI:http://hdl.handle.net/2142/1712
DOI:https://doi.org/10.1017/S0022112006003788
Publication Status:published or submitted for publication
Peer Reviewed:is peer reviewed
Rights Information:Copyright owned by Cambridge University Press 2007.
Date Available in IDEALS:2007-07-24


This item appears in the following Collection(s)

Item Statistics