Closed-loop-manipulated wake of a stationary square cylinder

M. M. Zhang, Y. Zhou, Li Cheng

Research output: Journal article publicationJournal articleAcademic researchpeer-review

14 Citations (Scopus)


Vortex shedding from a fixed rigid square cylinder in a cross flow was manipulated by perturbing the cylinder surface using piezo-ceramic actuators, which were activated by a feedback hot-wire signal via a proportional-integral- derivative (PID) controller. The manipulated flow was measured at a Reynolds number (Re) of 7,400 using particle image velocimetry (PIV), laser-induced fluorescence (LIF) flow visualisation, two-component laser Doppler anemometry (LDA), hot wires and load cells. It is observed that the vortex circulation, fluctuating streamwise velocity, lift and drag coefficients and mean drag coefficient may decrease by 71%, 40%, 51%, 42% and 20%, respectively, compared with the unperturbed flow, if the perturbation velocity of the cylinder surface is anti-phased with the flow lateral velocity associated with vortex shedding. On the other hand, these quantities may increase by 152%, 90%, 60%, 67% and 37%, respectively, given in-phased cylinder surface perturbation and vortex shedding. Similar effects are obtained at Re=3,200 and 9,500, respectively. The relationship between the perturbation and flow modification is examined, which provides insight into the physics behind the observation.
Original languageEnglish
Pages (from-to)75-85
Number of pages11
JournalExperiments in Fluids
Issue number1
Publication statusPublished - 1 Jul 2005

ASJC Scopus subject areas

  • Computational Mechanics
  • Mechanics of Materials
  • General Physics and Astronomy
  • Fluid Flow and Transfer Processes


Dive into the research topics of 'Closed-loop-manipulated wake of a stationary square cylinder'. Together they form a unique fingerprint.

Cite this