Influence of vortical structure impingement on the oscillation and rotation of flat plates

B. Liu, A. M. Hamed, Y. Jin, L. P. Chamorro

Research output: Contribution to journalArticle

Abstract

Wind tunnel experiments were performed to study the impact of coherent vortical structures, shed from a cylinder, on the oscillations and rotations of vertical flat plates with thickness ratio b/c=1/16, 3/16 and 5/16. Various combinations of cylinder diameter to plate chord ratio of d/c=1.1,0.8 and 0.5, and cylinder-plate spacing Ld/c∈[1,14] were studied to determine the role of the strength and scale of the vortices on the motion of the plates. The plate motion was characterized with high-temporal resolution accelerometer, gyroscope sensor and a laser tachometer. High temporal- and spatial-resolution flow measurements were performed using hotwire and planar particle image velocimetry (PIV). Plates were found to oscillate around two distinctive equilibrium positions depending on the strength of the vortices shed from the cylinder. For comparatively low cylinder-plate spacing Ld/c, the frequency of the shed vortices dominates the plate oscillation and the plate aligns with the mean direction of the flow. However, the plate motion transitions to an oscillation around an axis perpendicular to the mean flow with larger Ld/c and, eventually, the oscillation become dominated by the vortices shed by the plate. Given an initial impulse, the plates are also able to sustain multi-frequency rotations for large Ld/c ratios. In addition to governing the plate oscillations and equilibrium position, the spacing Ld/c is found to significantly modify the characteristics of the recirculation bubble and turbulence levels in the wake of the plate.

Original languageEnglish (US)
Pages (from-to)417-427
Number of pages11
JournalJournal of Fluids and Structures
Volume70
DOIs
StatePublished - Apr 1 2017

Fingerprint

Vortex flow
Tachometers
Gyroscopes
Flow measurement
Accelerometers
Velocity measurement
Wind tunnels
Turbulence
Lasers
Sensors
Experiments

ASJC Scopus subject areas

  • Mechanical Engineering

Cite this

Influence of vortical structure impingement on the oscillation and rotation of flat plates. / Liu, B.; Hamed, A. M.; Jin, Y.; Chamorro, L. P.

In: Journal of Fluids and Structures, Vol. 70, 01.04.2017, p. 417-427.

Research output: Contribution to journalArticle

@article{7b6d596f27994df8af0e772540b3cba7,
title = "Influence of vortical structure impingement on the oscillation and rotation of flat plates",
abstract = "Wind tunnel experiments were performed to study the impact of coherent vortical structures, shed from a cylinder, on the oscillations and rotations of vertical flat plates with thickness ratio b/c=1/16, 3/16 and 5/16. Various combinations of cylinder diameter to plate chord ratio of d/c=1.1,0.8 and 0.5, and cylinder-plate spacing Ld/c∈[1,14] were studied to determine the role of the strength and scale of the vortices on the motion of the plates. The plate motion was characterized with high-temporal resolution accelerometer, gyroscope sensor and a laser tachometer. High temporal- and spatial-resolution flow measurements were performed using hotwire and planar particle image velocimetry (PIV). Plates were found to oscillate around two distinctive equilibrium positions depending on the strength of the vortices shed from the cylinder. For comparatively low cylinder-plate spacing Ld/c, the frequency of the shed vortices dominates the plate oscillation and the plate aligns with the mean direction of the flow. However, the plate motion transitions to an oscillation around an axis perpendicular to the mean flow with larger Ld/c and, eventually, the oscillation become dominated by the vortices shed by the plate. Given an initial impulse, the plates are also able to sustain multi-frequency rotations for large Ld/c ratios. In addition to governing the plate oscillations and equilibrium position, the spacing Ld/c is found to significantly modify the characteristics of the recirculation bubble and turbulence levels in the wake of the plate.",
author = "B. Liu and Hamed, {A. M.} and Y. Jin and Chamorro, {L. P.}",
year = "2017",
month = "4",
day = "1",
doi = "10.1016/j.jfluidstructs.2017.02.011",
language = "English (US)",
volume = "70",
pages = "417--427",
journal = "Journal of Fluids and Structures",
issn = "0889-9746",
publisher = "Academic Press Inc.",

}

TY - JOUR

T1 - Influence of vortical structure impingement on the oscillation and rotation of flat plates

AU - Liu, B.

AU - Hamed, A. M.

AU - Jin, Y.

AU - Chamorro, L. P.

PY - 2017/4/1

Y1 - 2017/4/1

N2 - Wind tunnel experiments were performed to study the impact of coherent vortical structures, shed from a cylinder, on the oscillations and rotations of vertical flat plates with thickness ratio b/c=1/16, 3/16 and 5/16. Various combinations of cylinder diameter to plate chord ratio of d/c=1.1,0.8 and 0.5, and cylinder-plate spacing Ld/c∈[1,14] were studied to determine the role of the strength and scale of the vortices on the motion of the plates. The plate motion was characterized with high-temporal resolution accelerometer, gyroscope sensor and a laser tachometer. High temporal- and spatial-resolution flow measurements were performed using hotwire and planar particle image velocimetry (PIV). Plates were found to oscillate around two distinctive equilibrium positions depending on the strength of the vortices shed from the cylinder. For comparatively low cylinder-plate spacing Ld/c, the frequency of the shed vortices dominates the plate oscillation and the plate aligns with the mean direction of the flow. However, the plate motion transitions to an oscillation around an axis perpendicular to the mean flow with larger Ld/c and, eventually, the oscillation become dominated by the vortices shed by the plate. Given an initial impulse, the plates are also able to sustain multi-frequency rotations for large Ld/c ratios. In addition to governing the plate oscillations and equilibrium position, the spacing Ld/c is found to significantly modify the characteristics of the recirculation bubble and turbulence levels in the wake of the plate.

AB - Wind tunnel experiments were performed to study the impact of coherent vortical structures, shed from a cylinder, on the oscillations and rotations of vertical flat plates with thickness ratio b/c=1/16, 3/16 and 5/16. Various combinations of cylinder diameter to plate chord ratio of d/c=1.1,0.8 and 0.5, and cylinder-plate spacing Ld/c∈[1,14] were studied to determine the role of the strength and scale of the vortices on the motion of the plates. The plate motion was characterized with high-temporal resolution accelerometer, gyroscope sensor and a laser tachometer. High temporal- and spatial-resolution flow measurements were performed using hotwire and planar particle image velocimetry (PIV). Plates were found to oscillate around two distinctive equilibrium positions depending on the strength of the vortices shed from the cylinder. For comparatively low cylinder-plate spacing Ld/c, the frequency of the shed vortices dominates the plate oscillation and the plate aligns with the mean direction of the flow. However, the plate motion transitions to an oscillation around an axis perpendicular to the mean flow with larger Ld/c and, eventually, the oscillation become dominated by the vortices shed by the plate. Given an initial impulse, the plates are also able to sustain multi-frequency rotations for large Ld/c ratios. In addition to governing the plate oscillations and equilibrium position, the spacing Ld/c is found to significantly modify the characteristics of the recirculation bubble and turbulence levels in the wake of the plate.

UR - http://www.scopus.com/inward/record.url?scp=85014064937&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85014064937&partnerID=8YFLogxK

U2 - 10.1016/j.jfluidstructs.2017.02.011

DO - 10.1016/j.jfluidstructs.2017.02.011

M3 - Article

AN - SCOPUS:85014064937

VL - 70

SP - 417

EP - 427

JO - Journal of Fluids and Structures

JF - Journal of Fluids and Structures

SN - 0889-9746

ER -