Phase-averaged characteristics of flow around a circular cylinder under acoustic excitation control

Fujisawa, Nobuyuki; Takeda, Gentaro; Ike, N.

doi:10.1016/j.jfluidstructs.2003.10.004

Cited by 55 publications

(11 citation statements)

References 23 publications

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“…While active open-loop and active closed-loop controls are distinguished by whether there are sensors to active feedback. Rotating a cylinder at a certain speed [19,20], oscillating a cylinder in in-line or cross-flow at an appropriate frequency [21,22], steady or time-periodic blowing and suction [23,24], electromagnetic forcing [25], and distributed forcing controls [26] are typical examples for active controls. However, extra energy and relatively complex actuators are needed in active controls, which make it more difficult to implement in real situations.…”

Section: Introductionmentioning

confidence: 99%

Numerical evaluation of passive control of VIV by small control rods

Zhu

Yao

2015

Applied Ocean Research

113

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Section: Introductionmentioning

confidence: 99%

Numerical evaluation of passive control of VIV by small control rods

Zhu

Yao

2015

Applied Ocean Research

113

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“…As a pioneer of this research field, Prandtl (1928) applied suction for flow separation control on a circular cylinder after introducing the boundary layer theory. The flow control technology can be passive techniques, such as splitter plate (Mittal 2003a;Hwang et al 2003;Akilli et al 2008) and roughness (Achenbach 1971), as well as active techniques which include acoustic excitation (Fujisawa and Takeda 2003;Fujisawa et al 2004), synthetic jet (Tensi and Paillé 2002;Wang 2010, 2014), blowing (Li et al 2003) and so on.…”

Section: Introductionmentioning

confidence: 99%

Flow control over a circular cylinder using virtual moving surface boundary layer control

et al. 2019

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Flow control study of a circular cylinder is carried out using symmetric dielectric barrier discharge (DBD) plasma actuators at the Reynolds number of 10,000. Here, two symmetric DBD plasma actuators are located at the top and bottom of the circular cylinder, respectively, each of which induces pairs of counter-rotating starting vortices on both sides of exposed electrodes. The downstream starting vortices soon take the form of a wall jet along the freestream direction. On the other hand, the upstream starting vortices interact with the incoming flow remain for some time, bringing in high momentum from the freestream to near-wall region, enabling the boundary layer to withstand the adverse pressure gradient and suppressing the separation around the circular cylinder. The rotating vortical structures around the circular cylinder created by the plasma actuators lead to a reduction in the drag coefficient of up to 25%, providing a similar effect to moving surface boundary layer control (MSBLC). This configuration of symmetric DBD plasma actuator, which is studied for the first time in this investigation, is, therefore, called virtual MSBLC. Our results also indicated that the control effect of virtual MSBLC can be enhanced with an increase in the momentum coefficient of plasma jet. Unlike traditional MSBLC devices, the virtual MSBLC based on symmetric DBD plasma actuators do not have profile drag and are without complicated mechanical systems.

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“…Up to now, many techniques have been studied to control the flow with the aim to suppress the von Karman sheet or to influence the aerodynamic forces. These techniques varied from passive control which affects the surface of the bluff body, such as the addition of splitter plates [1,2], flexible filament [3], or changing its property like adding dimples [4] or grooves [5], to active control using synthetic jets [6][7][8][9], plasma actuators [10][11][12], blowing suction [13,14], flapping foil [15,16], electromagnetic forces [17,18] acoustic actuator [19,20].…”

Section: Introductionmentioning

confidence: 99%

Numerical investigation of the vibration effect of a flexible membrane on the flow behaviour around a circular cylinder

Maktouf

Moussa

Turki

2018

Eur. Phys. J. Appl. Phys.

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Active control of the flow behind a bluff body is obtained by integrating a vibrating membrane. A numerical study has been conducted to investigate the effect of the vibration of a flexible membrane, stuck to the rear side of a circular cylinder, on the global flow parameters such as the Strouhal number, the drag and lift coefficients. The shape of the membrane is evolving as a vibrating chord using a dynamic mesh. The governing equations of 2D and laminar flow have been solved using ANSYS Fluent 16.0 as a solver and the Gambit as a modeler. The motion of the membrane is managed by two parameters: frequency f and amplitude A. The effect of the flexible membrane motion is studied for the range of conditions as 0.1 Hz ≤ f ≤ 6 Hz and 5 × 10−4 m ≤ A ≤ 10−3 m at a fixed Reynolds number, Re = 150. Three different sizes of the flexible membrane have been studied. Results show that a beat phenomenon affects the drag coefficient. The amplitude does not affect significantly the Strouhal number as well as drag and lift coefficients. By increasing the size of the flexible membrane, we show a lift enhancement by a growth rate equal to 39.15% comparing to the uncontrolled case.

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Phase-averaged characteristics of flow around a circular cylinder under acoustic excitation control

Cited by 55 publications

References 23 publications

Numerical evaluation of passive control of VIV by small control rods

Numerical evaluation of passive control of VIV by small control rods

Flow control over a circular cylinder using virtual moving surface boundary layer control

Numerical investigation of the vibration effect of a flexible membrane on the flow behaviour around a circular cylinder

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