The University of Southampton
University of Southampton Institutional Repository

The instantaneous structure of turbulent boundary layers over surfaces with spanwise heterogeneity

The instantaneous structure of turbulent boundary layers over surfaces with spanwise heterogeneity
The instantaneous structure of turbulent boundary layers over surfaces with spanwise heterogeneity
Turbulent flows over surfaces with extensive roughness variation in the spanwise direction induce a secondary flow in the form of streamwise aligned counter-rotating vortices. In this study, we conduct cross-plane stereoscopic particle image velocimetry (SPIV) measurements over surfaces constructed from spanwise-alternating smooth and rough strips to emulate spanwise heterogeneity in a rough-walled surface. The half-spanwise-wavelength of the alternating rough and smooth strips S varies from S/δ = 0.32–3.63,relative to the spanwise-averaged boundary layer thickness,δ. Two limiting cases are observed when S/δ 1 and 1, where the size of secondary flow is limited by δ and S, respectively. Consequently, the regions away from the secondary flow scale according to their local shear stress when S/δ 1 and become spanwise homogeneous when S/δ 1. We observe that when S/δ ≈ 1, the secondary flow is particularly strong and appears to fill the entire wall normal extent of the boundary layer. In this condition, we observe that the spanwise location of the secondary flow is highly time-dependent.
Wangsawijaya, Dea Daniella
b9f307f6-2828-416f-bc41-a025ecf49098
de Silva, Charitha
c1f62898-a111-464b-9b3e-7ca60de5ed19
Baidya, Rio
690aa4fe-8c5e-4ae2-a4d9-fe3dc90ec6e3
Chung, Daniel
bf772c11-a5ad-461c-822b-8f5d10b87b92
Marusic, Ivan
4651922b-cc4e-4ed0-9e78-243025bd902f
Hutchins, Nicholas
0ffab046-7345-4f2c-83aa-42da4ab24167
Wangsawijaya, Dea Daniella
b9f307f6-2828-416f-bc41-a025ecf49098
de Silva, Charitha
c1f62898-a111-464b-9b3e-7ca60de5ed19
Baidya, Rio
690aa4fe-8c5e-4ae2-a4d9-fe3dc90ec6e3
Chung, Daniel
bf772c11-a5ad-461c-822b-8f5d10b87b92
Marusic, Ivan
4651922b-cc4e-4ed0-9e78-243025bd902f
Hutchins, Nicholas
0ffab046-7345-4f2c-83aa-42da4ab24167

Wangsawijaya, Dea Daniella, de Silva, Charitha, Baidya, Rio, Chung, Daniel, Marusic, Ivan and Hutchins, Nicholas (2019) The instantaneous structure of turbulent boundary layers over surfaces with spanwise heterogeneity. In The 11th International Symposium on Turbulence and Shear Flow Phenomena: TSFP11. 6 pp .

Record type: Conference or Workshop Item (Paper)

Abstract

Turbulent flows over surfaces with extensive roughness variation in the spanwise direction induce a secondary flow in the form of streamwise aligned counter-rotating vortices. In this study, we conduct cross-plane stereoscopic particle image velocimetry (SPIV) measurements over surfaces constructed from spanwise-alternating smooth and rough strips to emulate spanwise heterogeneity in a rough-walled surface. The half-spanwise-wavelength of the alternating rough and smooth strips S varies from S/δ = 0.32–3.63,relative to the spanwise-averaged boundary layer thickness,δ. Two limiting cases are observed when S/δ 1 and 1, where the size of secondary flow is limited by δ and S, respectively. Consequently, the regions away from the secondary flow scale according to their local shear stress when S/δ 1 and become spanwise homogeneous when S/δ 1. We observe that when S/δ ≈ 1, the secondary flow is particularly strong and appears to fill the entire wall normal extent of the boundary layer. In this condition, we observe that the spanwise location of the secondary flow is highly time-dependent.

This record has no associated files available for download.

More information

Published date: 2 August 2019
Venue - Dates: 11th International Symposium on Turbulence and Shear Flow Phenomena, , Southampton, United Kingdom, 2019-07-30 - 2019-08-02

Identifiers

Local EPrints ID: 470095
URI: http://eprints.soton.ac.uk/id/eprint/470095
PURE UUID: a2526905-62e9-4efb-8d41-d3df48b068c5
ORCID for Dea Daniella Wangsawijaya: ORCID iD orcid.org/0000-0002-7072-4245

Catalogue record

Date deposited: 03 Oct 2022 16:49
Last modified: 04 Oct 2022 02:03

Export record

Contributors

Author: Dea Daniella Wangsawijaya ORCID iD
Author: Charitha de Silva
Author: Rio Baidya
Author: Daniel Chung
Author: Ivan Marusic
Author: Nicholas Hutchins

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.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

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.

×