Secondary motion in turbulent pipe flow with three-dimensional roughness

Leon Zen Hsien Chan, M. MacDonald, D. Chung, N. Hutchins, A. Ooi

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

The occurrence of secondary flows is investigated for three-dimensional sinusoidal roughness where the wavelength and height of the roughness elements are systematically altered. The flow spanned from the transitionally rough regime up to the fully rough regime and the solidity of the roughness ranged from a wavy, sparse roughness to a dense roughness. Analysing the time-averaged velocity, secondary flows are observed in all of the cases, reflected in the coherent stress profile which is dominant in the vicinity of the roughness elements. The roughness sublayer, defined as the region where the coherent stress is non-zero, scales with the roughness wavelength when the roughness is geometrically scaled (proportional increase in both roughness height and wavelength) and when the wavelength increases at fixed roughness height. Premultiplied energy spectra of the streamwise velocity turbulent fluctuations show that energy is reorganised from the largest streamwise wavelengths to the shorter streamwise wavelengths. The peaks in the premultiplied spectra at the streamwise and spanwise wavelengths are correlated with the roughness wavelength in the fully rough regime. Current simulations show that the spanwise scale of roughness determines the occurrence of large-scale secondary flows.

Original languageEnglish
Pages (from-to)5-33
Number of pages29
JournalJournal of Fluid Mechanics
Volume854
DOIs
Publication statusPublished - 10 Nov 2018

Fingerprint

pipe flow
Pipe flow
roughness
Surface roughness
Wavelength
wavelengths
secondary flow
Secondary flow
occurrences
energy spectra

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Cite this

Chan, Leon Zen Hsien ; MacDonald, M. ; Chung, D. ; Hutchins, N. ; Ooi, A. / Secondary motion in turbulent pipe flow with three-dimensional roughness. In: Journal of Fluid Mechanics. 2018 ; Vol. 854. pp. 5-33.
@article{0ae016dd152c4d2eabe760241a835ce5,
title = "Secondary motion in turbulent pipe flow with three-dimensional roughness",
abstract = "The occurrence of secondary flows is investigated for three-dimensional sinusoidal roughness where the wavelength and height of the roughness elements are systematically altered. The flow spanned from the transitionally rough regime up to the fully rough regime and the solidity of the roughness ranged from a wavy, sparse roughness to a dense roughness. Analysing the time-averaged velocity, secondary flows are observed in all of the cases, reflected in the coherent stress profile which is dominant in the vicinity of the roughness elements. The roughness sublayer, defined as the region where the coherent stress is non-zero, scales with the roughness wavelength when the roughness is geometrically scaled (proportional increase in both roughness height and wavelength) and when the wavelength increases at fixed roughness height. Premultiplied energy spectra of the streamwise velocity turbulent fluctuations show that energy is reorganised from the largest streamwise wavelengths to the shorter streamwise wavelengths. The peaks in the premultiplied spectra at the streamwise and spanwise wavelengths are correlated with the roughness wavelength in the fully rough regime. Current simulations show that the spanwise scale of roughness determines the occurrence of large-scale secondary flows.",
author = "Chan, {Leon Zen Hsien} and M. MacDonald and D. Chung and N. Hutchins and A. Ooi",
year = "2018",
month = "11",
day = "10",
doi = "10.1017/jfm.2018.570",
language = "English",
volume = "854",
pages = "5--33",
journal = "Journal of Fluid Mechanics",
issn = "0022-1120",
publisher = "Cambridge University Press",

}

Secondary motion in turbulent pipe flow with three-dimensional roughness. / Chan, Leon Zen Hsien; MacDonald, M.; Chung, D.; Hutchins, N.; Ooi, A.

In: Journal of Fluid Mechanics, Vol. 854, 10.11.2018, p. 5-33.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Secondary motion in turbulent pipe flow with three-dimensional roughness

AU - Chan, Leon Zen Hsien

AU - MacDonald, M.

AU - Chung, D.

AU - Hutchins, N.

AU - Ooi, A.

PY - 2018/11/10

Y1 - 2018/11/10

N2 - The occurrence of secondary flows is investigated for three-dimensional sinusoidal roughness where the wavelength and height of the roughness elements are systematically altered. The flow spanned from the transitionally rough regime up to the fully rough regime and the solidity of the roughness ranged from a wavy, sparse roughness to a dense roughness. Analysing the time-averaged velocity, secondary flows are observed in all of the cases, reflected in the coherent stress profile which is dominant in the vicinity of the roughness elements. The roughness sublayer, defined as the region where the coherent stress is non-zero, scales with the roughness wavelength when the roughness is geometrically scaled (proportional increase in both roughness height and wavelength) and when the wavelength increases at fixed roughness height. Premultiplied energy spectra of the streamwise velocity turbulent fluctuations show that energy is reorganised from the largest streamwise wavelengths to the shorter streamwise wavelengths. The peaks in the premultiplied spectra at the streamwise and spanwise wavelengths are correlated with the roughness wavelength in the fully rough regime. Current simulations show that the spanwise scale of roughness determines the occurrence of large-scale secondary flows.

AB - The occurrence of secondary flows is investigated for three-dimensional sinusoidal roughness where the wavelength and height of the roughness elements are systematically altered. The flow spanned from the transitionally rough regime up to the fully rough regime and the solidity of the roughness ranged from a wavy, sparse roughness to a dense roughness. Analysing the time-averaged velocity, secondary flows are observed in all of the cases, reflected in the coherent stress profile which is dominant in the vicinity of the roughness elements. The roughness sublayer, defined as the region where the coherent stress is non-zero, scales with the roughness wavelength when the roughness is geometrically scaled (proportional increase in both roughness height and wavelength) and when the wavelength increases at fixed roughness height. Premultiplied energy spectra of the streamwise velocity turbulent fluctuations show that energy is reorganised from the largest streamwise wavelengths to the shorter streamwise wavelengths. The peaks in the premultiplied spectra at the streamwise and spanwise wavelengths are correlated with the roughness wavelength in the fully rough regime. Current simulations show that the spanwise scale of roughness determines the occurrence of large-scale secondary flows.

UR - http://www.scopus.com/inward/record.url?scp=85052701478&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85052701478&partnerID=8YFLogxK

U2 - 10.1017/jfm.2018.570

DO - 10.1017/jfm.2018.570

M3 - Article

VL - 854

SP - 5

EP - 33

JO - Journal of Fluid Mechanics

JF - Journal of Fluid Mechanics

SN - 0022-1120

ER -