Perturbed interaction between vortex shedding and induced vibration

Li, Cheng; Zhou, Yu; Zhang, Ming Ming

doi:10.1016/s0889-9746(03)00042-2

Cited by 66 publications

(32 citation statements)

References 21 publications

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“…However, the performance of their system was not significantly superior to the openloop system used by Cheng et al 8 One may surmise that their feedback signal was from flow only, containing no information on structural vibration or flow-structure interactions, and might not provide the optimum feedback signal to control fluid-structure interactions. This begs the question: The present investigation pursues two objectives: ͑1͒ to improve the control system developed by Cheng et al 8 and Zhang et al 17 and find an optimum scheme to control fluidstructure interactions, and ͑2͒ to shed light upon the underlying physics of flow-structure interaction under external perturbation. Three control schemes, utilizing feedback signals from flow, structural vibration, or a combination of both, are considered and compared.…”

Section: Introductionmentioning

confidence: 82%

“…7 Recently, Cheng et al 8 investigated a novel perturbation technique using curved piezoceramic actuators embedded underneath the surface of a square cylinder to alter interactions between a flexibly supported cylinder and cross flow. Given a properly set perturbation frequency, both vortex shedding and vortex-induced vibration were significantly reduced as a result from actuator-generated surface perturbation.…”

Section: Introductionmentioning

confidence: 99%

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Closed-loop-controlled vortex shedding and vibration of a flexibly supported square cylinder under different schemes

Zhang

Zhou

2004

Physics of Fluids

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Different schemes were experimentally investigated of the closed-loop control of vortex shedding from a spring-supported square cylinder in cross flow. The control action was implemented through the perturbation of one cylinder surface, which was generated by three piezoelectric ceramic actuators, embedded underneath the surface and controlled by a proportional-integral-derivative controller. Three control schemes were investigated using different feedback signals, including the turbulent flow signal measured by a hot wire, flow-induced structural oscillation signal obtained by a laser vibrometer, and a combination of both signals. An investigation was conducted at the resonance condition, when the vortex-shedding frequency coincided with the natural frequency of the fluid-structure system. The flow and structural vibration were measured using particle image velocimetry, laser-induced fluorescence flow visualization, a laser Doppler anemometer, and a laser vibrometer. It was observed that the control scheme based on the feedback of both flow and structural oscillation led to the almost complete destruction of the Kármán vortex street and a reduction in the structural vibration, vortex shedding strength, and drag coefficient by 82%, 65%, and 35%, respectively, outperforming by far an open-loop control as well as the other two closed-loop schemes.

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Section: Introductionmentioning

confidence: 82%

Section: Introductionmentioning

confidence: 99%

Closed-loop-controlled vortex shedding and vibration of a flexibly supported square cylinder under different schemes

Zhang

Zhou

2004

Physics of Fluids

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“…As mentioned earlier, the measurement location of u 1 was carefully selected so that u 1 would not be influenced by the vortex-airfoil interaction. It may be inferred that it is the perturbation that has modified the phase of u 2 with respect to u 1 In an investigation to control the flow-induced vibration on a laterally oscillating square cylinder, Cheng et al 18 found that the spectral phase between the lateral structural displacement Y and the streamwise fluctuating flow velocity u was approximately equivalent to that between the lateral cylinder oscillating velocity, Ẏ , and the lateral flow velocity v. The present case differs from theirs in that the airfoil leading edge is bombarded by incident vortices, instead of shedding vortices. Therefore, one experiment was carried out to investigate the relationship between flow and perturbation force.…”

Section: -8mentioning

confidence: 99%

“…See Ariyur and Krstić 16 and Swaminathan et al 17 for examples. Recently, Cheng et al 18 proposed a perturbation technique to control fluidstructure interactions, which proved to be very effective in altering the strength of vortices shed from a cylinder and subsequently the structural vibration. 18,19 Inspired by that success, the present work extends the perturbation technique for a new application, i.e., modifying the blade-vortex interaction and subsequently suppressing the BVI noise.…”

Section: Introductionmentioning

confidence: 99%

Closed-loop controlled vortex-airfoil interactions

Zhang

Zhou

2006

Physics of Fluids

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Closed-loop controlled interactions between an airfoil and impinging vortices were experimentally investigated. This work aims to minimize the fluctuating flow pressure ͑p͒ at the leading edge of the airfoil, which is a major source of the blade-vortex interaction noises commonly seen in rotorcrafts. Piezoceramic actuators were used to create a local surface perturbation near the leading edge of the airfoil in order to alter the airfoil-vortex interaction. Two closed-loop control schemes were investigated, which deployed p and the streamwise fluctuating flow velocity ͑u͒ as the feedback signal, respectively. As the control effect on p was measured using a fast response pressure transducer, the oncoming vortical flow was monitored using a particle image velocimetry and a hot wire. It was found that the control scheme based on the feedback signal u led to a pronounced impairment in the strength of oncoming vortices and meanwhile a maximum reduction in p by 39%, outperforming the control scheme based on the feedback signal p. Physics behind the observations is discussed.

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“…Along this line of thinking, a surface perturbation technique was proposed by Cheng et al, 19 aiming at the simultaneous control of both flow field and structural vibration. The technique makes use of curved piezo-ceramic actuators, embedded underneath the structural surface, to generate a controllable transverse motion on a structural surface for altering fluid-structure interactions.…”

Section: Introductionmentioning

confidence: 99%

Closed-loop control of flow-induced sound in a flow duct with downstream resonant cavities

Halim

2013

The Journal of the Acoustical Society of America

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A closed-loop-controlled surface perturbation technique was developed for controlling the flow-induced sound in a flow duct and acoustic resonance inside downstream cavities. The surface perturbation was created by piezo-ceramic THUNDER (THin layer composite UNimorph Driver and sEnsoR) actuators embedded underneath the surface of a test model with a semi-circular leading edge. A modified closed-loop control scheme based on the down-sampling theory was proposed and implemented due to the practical vibration characteristic limitation of THUNDER actuators. The optimally tuned control achieved a sound pressure reduction of 17.5 dB in the duct and 22.6 dB inside the cavity at the vortex shedding frequency, respectively. Changes brought up by the control in both flow and acoustic fields were analyzed in terms of the spectrum phase shift of the flow field over the upper surface of the test model, and a shift in the vortex shedding frequency. The physical mechanism behind the control was investigated in the view of developing an optimal control strategy.

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Perturbed interaction between vortex shedding and induced vibration

Cited by 66 publications

References 21 publications

Closed-loop-controlled vortex shedding and vibration of a flexibly supported square cylinder under different schemes

Closed-loop-controlled vortex shedding and vibration of a flexibly supported square cylinder under different schemes

Closed-loop controlled vortex-airfoil interactions

Closed-loop control of flow-induced sound in a flow duct with downstream resonant cavities

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