An investigation into the effects of highly directional surface roughness on turbulent boundary layers

B. Nugroho, V. Kulandaivelu, Zambri Harun, N. Hutchins, J. P. Monty

Research output: Chapter in Book/Report/Conference proceedingConference contribution

6 Citations (Scopus)

Abstract

The development of a zero pressure gradient turbulent boundary layer over a diverging and converging riblet arrangement is investigated experimentally. Such surface patterns are inspired by the very interesting work of Koeltzsch et al (6). Hot-wire studies show that these small, highly-ordered surface roughness patterns impose a high degree of three-dimensionality onto the boundary layer, causing a 100% variation in boundary layer thickness across the spanwise wavelength of the surface pattern (this, despite the fact, that the roughness height is less than 1% of the unperturbed boundary layer thickness). Detailed boundary layer traverses reveal that the local velocity above the diverging region is higher than the converging region. These results, together with turbulence intensity and energy spectra data, lead us to propose that these surface patterns have induced a large-scale counter-rotating vortex pattern into the boundary layer. Under this hypothesis, the observed three-dimensionality is primarily a result of the redistribution of turbulent profiles due to these secondary flows.

Original languageEnglish
Title of host publication17th Australasian Fluid Mechanics Conference 2010
Pages361-364
Number of pages4
Publication statusPublished - 2010
Externally publishedYes
Event17th Australasian Fluid Mechanics Conference 2010, 17AFMC - Auckland
Duration: 5 Dec 20109 Dec 2010

Other

Other17th Australasian Fluid Mechanics Conference 2010, 17AFMC
CityAuckland
Period5/12/109/12/10

Fingerprint

Boundary layers
Surface roughness
Secondary flow
Pressure gradient
Vortex flow
Turbulence
Wire
Wavelength

ASJC Scopus subject areas

  • Fluid Flow and Transfer Processes

Cite this

Nugroho, B., Kulandaivelu, V., Harun, Z., Hutchins, N., & Monty, J. P. (2010). An investigation into the effects of highly directional surface roughness on turbulent boundary layers. In 17th Australasian Fluid Mechanics Conference 2010 (pp. 361-364)

An investigation into the effects of highly directional surface roughness on turbulent boundary layers. / Nugroho, B.; Kulandaivelu, V.; Harun, Zambri; Hutchins, N.; Monty, J. P.

17th Australasian Fluid Mechanics Conference 2010. 2010. p. 361-364.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Nugroho, B, Kulandaivelu, V, Harun, Z, Hutchins, N & Monty, JP 2010, An investigation into the effects of highly directional surface roughness on turbulent boundary layers. in 17th Australasian Fluid Mechanics Conference 2010. pp. 361-364, 17th Australasian Fluid Mechanics Conference 2010, 17AFMC, Auckland, 5/12/10.
Nugroho B, Kulandaivelu V, Harun Z, Hutchins N, Monty JP. An investigation into the effects of highly directional surface roughness on turbulent boundary layers. In 17th Australasian Fluid Mechanics Conference 2010. 2010. p. 361-364
Nugroho, B. ; Kulandaivelu, V. ; Harun, Zambri ; Hutchins, N. ; Monty, J. P. / An investigation into the effects of highly directional surface roughness on turbulent boundary layers. 17th Australasian Fluid Mechanics Conference 2010. 2010. pp. 361-364
@inproceedings{05016a2d1f2a422aaf9f95f839f48bb3,
title = "An investigation into the effects of highly directional surface roughness on turbulent boundary layers",
abstract = "The development of a zero pressure gradient turbulent boundary layer over a diverging and converging riblet arrangement is investigated experimentally. Such surface patterns are inspired by the very interesting work of Koeltzsch et al (6). Hot-wire studies show that these small, highly-ordered surface roughness patterns impose a high degree of three-dimensionality onto the boundary layer, causing a 100{\%} variation in boundary layer thickness across the spanwise wavelength of the surface pattern (this, despite the fact, that the roughness height is less than 1{\%} of the unperturbed boundary layer thickness). Detailed boundary layer traverses reveal that the local velocity above the diverging region is higher than the converging region. These results, together with turbulence intensity and energy spectra data, lead us to propose that these surface patterns have induced a large-scale counter-rotating vortex pattern into the boundary layer. Under this hypothesis, the observed three-dimensionality is primarily a result of the redistribution of turbulent profiles due to these secondary flows.",
author = "B. Nugroho and V. Kulandaivelu and Zambri Harun and N. Hutchins and Monty, {J. P.}",
year = "2010",
language = "English",
isbn = "9781617829130",
pages = "361--364",
booktitle = "17th Australasian Fluid Mechanics Conference 2010",

}

TY - GEN

T1 - An investigation into the effects of highly directional surface roughness on turbulent boundary layers

AU - Nugroho, B.

AU - Kulandaivelu, V.

AU - Harun, Zambri

AU - Hutchins, N.

AU - Monty, J. P.

PY - 2010

Y1 - 2010

N2 - The development of a zero pressure gradient turbulent boundary layer over a diverging and converging riblet arrangement is investigated experimentally. Such surface patterns are inspired by the very interesting work of Koeltzsch et al (6). Hot-wire studies show that these small, highly-ordered surface roughness patterns impose a high degree of three-dimensionality onto the boundary layer, causing a 100% variation in boundary layer thickness across the spanwise wavelength of the surface pattern (this, despite the fact, that the roughness height is less than 1% of the unperturbed boundary layer thickness). Detailed boundary layer traverses reveal that the local velocity above the diverging region is higher than the converging region. These results, together with turbulence intensity and energy spectra data, lead us to propose that these surface patterns have induced a large-scale counter-rotating vortex pattern into the boundary layer. Under this hypothesis, the observed three-dimensionality is primarily a result of the redistribution of turbulent profiles due to these secondary flows.

AB - The development of a zero pressure gradient turbulent boundary layer over a diverging and converging riblet arrangement is investigated experimentally. Such surface patterns are inspired by the very interesting work of Koeltzsch et al (6). Hot-wire studies show that these small, highly-ordered surface roughness patterns impose a high degree of three-dimensionality onto the boundary layer, causing a 100% variation in boundary layer thickness across the spanwise wavelength of the surface pattern (this, despite the fact, that the roughness height is less than 1% of the unperturbed boundary layer thickness). Detailed boundary layer traverses reveal that the local velocity above the diverging region is higher than the converging region. These results, together with turbulence intensity and energy spectra data, lead us to propose that these surface patterns have induced a large-scale counter-rotating vortex pattern into the boundary layer. Under this hypothesis, the observed three-dimensionality is primarily a result of the redistribution of turbulent profiles due to these secondary flows.

UR - http://www.scopus.com/inward/record.url?scp=84857029116&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84857029116&partnerID=8YFLogxK

M3 - Conference contribution

AN - SCOPUS:84857029116

SN - 9781617829130

SP - 361

EP - 364

BT - 17th Australasian Fluid Mechanics Conference 2010

ER -