On the interaction between a turbulent open channel flow and an axial-flow turbine

L. P. Chamorro, C. Hill, S. Morton, C. Ellis, R. E.A. Arndt, F. Sotiropoulos

Research output: Contribution to journalArticle

Abstract

A laboratory experiment was performed to study the dynamically rich interaction of a turbulent open channel flow with a bed-mounted axial-flow hydrokinetic turbine. An acoustic Doppler velocimeter and a torque transducer were used to simultaneously measure at high temporal resolution the three velocity components of the flow at various locations upstream of the turbine and in the wake region and turbine power, respectively. Results show that for sufficiently low frequencies the instantaneous power generated by the turbine is modulated by the turbulent structure of the approach flow. The critical frequency above which the response of the turbine is decoupled from the turbulent flow structure is shown to vary linearly with the angular frequency of the rotor. The measurements elucidate the structure of the turbulent turbine wake, which is shown to persist for at least fifteen rotor diameters downstream of the rotor, and a new approach is proposed to quantify the wake recovery, based on the growth of the largest scale motions in the flow. Spectral analysis is employed to demonstrate the dominant effect of the tip vortices in the energy distribution in the near-wake region and uncover meandering motions.

Original languageEnglish (US)
Pages (from-to)658-670
Number of pages13
JournalJournal of Fluid Mechanics
Volume716
DOIs
StatePublished - Feb 1 2013
Externally publishedYes

Fingerprint

axial flow turbines
open channel flow
Open channel flow
Axial flow
turbines
Turbines
wakes
rotors
Rotors
interactions
hydromechanics
near wakes
Velocimeters
axial flow
critical frequencies
Flow structure
temporal resolution
turbulent flow
Spectrum analysis
upstream

Keywords

  • channel flow
  • hydraulics
  • waves/free-surface flows

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Cite this

On the interaction between a turbulent open channel flow and an axial-flow turbine. / Chamorro, L. P.; Hill, C.; Morton, S.; Ellis, C.; Arndt, R. E.A.; Sotiropoulos, F.

In: Journal of Fluid Mechanics, Vol. 716, 01.02.2013, p. 658-670.

Research output: Contribution to journalArticle

Chamorro, L. P. ; Hill, C. ; Morton, S. ; Ellis, C. ; Arndt, R. E.A. ; Sotiropoulos, F. / On the interaction between a turbulent open channel flow and an axial-flow turbine. In: Journal of Fluid Mechanics. 2013 ; Vol. 716. pp. 658-670.
@article{dd75f2a197b740f09613ac8eff867692,
title = "On the interaction between a turbulent open channel flow and an axial-flow turbine",
abstract = "A laboratory experiment was performed to study the dynamically rich interaction of a turbulent open channel flow with a bed-mounted axial-flow hydrokinetic turbine. An acoustic Doppler velocimeter and a torque transducer were used to simultaneously measure at high temporal resolution the three velocity components of the flow at various locations upstream of the turbine and in the wake region and turbine power, respectively. Results show that for sufficiently low frequencies the instantaneous power generated by the turbine is modulated by the turbulent structure of the approach flow. The critical frequency above which the response of the turbine is decoupled from the turbulent flow structure is shown to vary linearly with the angular frequency of the rotor. The measurements elucidate the structure of the turbulent turbine wake, which is shown to persist for at least fifteen rotor diameters downstream of the rotor, and a new approach is proposed to quantify the wake recovery, based on the growth of the largest scale motions in the flow. Spectral analysis is employed to demonstrate the dominant effect of the tip vortices in the energy distribution in the near-wake region and uncover meandering motions.",
keywords = "channel flow, hydraulics, waves/free-surface flows",
author = "Chamorro, {L. P.} and C. Hill and S. Morton and C. Ellis and Arndt, {R. E.A.} and F. Sotiropoulos",
year = "2013",
month = "2",
day = "1",
doi = "10.1017/jfm.2012.571",
language = "English (US)",
volume = "716",
pages = "658--670",
journal = "Journal of Fluid Mechanics",
issn = "0022-1120",
publisher = "Cambridge University Press",

}

TY - JOUR

T1 - On the interaction between a turbulent open channel flow and an axial-flow turbine

AU - Chamorro, L. P.

AU - Hill, C.

AU - Morton, S.

AU - Ellis, C.

AU - Arndt, R. E.A.

AU - Sotiropoulos, F.

PY - 2013/2/1

Y1 - 2013/2/1

N2 - A laboratory experiment was performed to study the dynamically rich interaction of a turbulent open channel flow with a bed-mounted axial-flow hydrokinetic turbine. An acoustic Doppler velocimeter and a torque transducer were used to simultaneously measure at high temporal resolution the three velocity components of the flow at various locations upstream of the turbine and in the wake region and turbine power, respectively. Results show that for sufficiently low frequencies the instantaneous power generated by the turbine is modulated by the turbulent structure of the approach flow. The critical frequency above which the response of the turbine is decoupled from the turbulent flow structure is shown to vary linearly with the angular frequency of the rotor. The measurements elucidate the structure of the turbulent turbine wake, which is shown to persist for at least fifteen rotor diameters downstream of the rotor, and a new approach is proposed to quantify the wake recovery, based on the growth of the largest scale motions in the flow. Spectral analysis is employed to demonstrate the dominant effect of the tip vortices in the energy distribution in the near-wake region and uncover meandering motions.

AB - A laboratory experiment was performed to study the dynamically rich interaction of a turbulent open channel flow with a bed-mounted axial-flow hydrokinetic turbine. An acoustic Doppler velocimeter and a torque transducer were used to simultaneously measure at high temporal resolution the three velocity components of the flow at various locations upstream of the turbine and in the wake region and turbine power, respectively. Results show that for sufficiently low frequencies the instantaneous power generated by the turbine is modulated by the turbulent structure of the approach flow. The critical frequency above which the response of the turbine is decoupled from the turbulent flow structure is shown to vary linearly with the angular frequency of the rotor. The measurements elucidate the structure of the turbulent turbine wake, which is shown to persist for at least fifteen rotor diameters downstream of the rotor, and a new approach is proposed to quantify the wake recovery, based on the growth of the largest scale motions in the flow. Spectral analysis is employed to demonstrate the dominant effect of the tip vortices in the energy distribution in the near-wake region and uncover meandering motions.

KW - channel flow

KW - hydraulics

KW - waves/free-surface flows

UR - http://www.scopus.com/inward/record.url?scp=84878990801&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84878990801&partnerID=8YFLogxK

U2 - 10.1017/jfm.2012.571

DO - 10.1017/jfm.2012.571

M3 - Article

AN - SCOPUS:84878990801

VL - 716

SP - 658

EP - 670

JO - Journal of Fluid Mechanics

JF - Journal of Fluid Mechanics

SN - 0022-1120

ER -