On the dynamics of flexible plates under rotational motions

Shifeng Fu, Yaqing Jin, Jin Tae Kim, Zhongyu Mao, Yuan Zheng, Leonardo P. Chamorro

Research output: Contribution to journalArticle

Abstract

The reconfiguration of low-aspect-ratio flexible plates, required power and induced flow under pure rotation were experimentally inspected for various plate stiffness and angular velocities ω. Particle tracking velocimetry (PTV) and particle image velocimetry (PIV) were used to characterize the plate deformation along their span as well as the flow and turbulence statistics in the vicinity of the structures. Results show the characteristic role of stiffness and ω in modulating the structure reconfiguration, power required and induced flow. The inspected configurations allowed inspecting various plate deformations ranging from minor to extreme bending over 90 between the tangents of the two tips. Regardless of the case, the plates did not undergo noticeable deformation in the last ∼30% of the span. Location of the maximum deformation along the plate followed a trend s m ∝ log(Ca), where Ca is the Cauchy number, which indicated that s m is roughly fixed at sufficiently large Ca. The angle (α) between the plate in the vicinity of the tip and the tangential vector of the motions exhibited two distinctive, nearly-linear trends as a function of Ca, within Ca ∈ (0, 15) and Ca ∈ (20, 70), with a matching within these Ca at Ca > 70, α ≈ 45 . Induced flow revealed a local maximum of the turbulence levels at around 60% of the span of the plate; however, the largest turbulence enhancement occurred near the tip. Flexibility of the plate strongly modulated the spatial distribution of small-scale vortical structures; they were located along the plate wake in the stiffer plate and relatively concentrated near the tip in the low-stiffness plate. Due to relatively large deformation, rotational and wake effects, a simple formulation for predicting the mean reconfiguration showed offset; however, a bulk, constant factor on ω accounted for the offset between predictions and measurements at deformation reaching ∼60 between the tips.

Original languageEnglish (US)
Article number3384
JournalEnergies
Volume11
Issue number12
DOIs
StatePublished - Dec 1 2018

Fingerprint

Motion
Turbulence
Stiffness
Velocity measurement
Reconfiguration
Angular velocity
Wake
Spatial distribution
Aspect ratio
Statistics
Linear Trend
Particle Tracking
Large Deformation
Spatial Distribution
Aspect Ratio
Tangent line
Cauchy
Minor
Extremes
Enhancement

Keywords

  • PIV
  • Plate oscillation
  • Rotation
  • Turbulence

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Energy Engineering and Power Technology
  • Energy (miscellaneous)
  • Control and Optimization
  • Electrical and Electronic Engineering

Cite this

On the dynamics of flexible plates under rotational motions. / Fu, Shifeng; Jin, Yaqing; Kim, Jin Tae; Mao, Zhongyu; Zheng, Yuan; Chamorro, Leonardo P.

In: Energies, Vol. 11, No. 12, 3384, 01.12.2018.

Research output: Contribution to journalArticle

Fu, Shifeng ; Jin, Yaqing ; Kim, Jin Tae ; Mao, Zhongyu ; Zheng, Yuan ; Chamorro, Leonardo P. / On the dynamics of flexible plates under rotational motions. In: Energies. 2018 ; Vol. 11, No. 12.
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