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Feedback Control of Flow Field behind a Square Cylinder with Inline Oscillations

Journal Name:

  • Journal of Control Engineering and Technology

Publication Year:

  • 2011

Key Words:

Author Name
Abstract (2. Language): 
Control of vortex shedding from a bluff body and vortex induced vibration is of fundamental interest. In recent years a significant amount of work is going on in different engineering and industrial problem such as offshore exploration, marine hydraulics, MEMS (microelectromechanical systems), electronics cooling etc. The present study reports images and signals recorded in the wake of a square cylinder oscillating in the streamwise direction using PIV and HWA. Wakes of a stationary cylinder, one with forced oscillations at the vortex shedding frequency of a stationary cylinder and the flow field resulting from feedback are compared. In the third experiment, cylinder movement is driven by a hotwire signal with the probe placed in the near wake and, in this respect the wake unsteadiness is fed back to the cylinder motion. The amplitude of cylinder movement is about 13% of the cylinder edge. The interest here is towards active control of the flow field at intermediate Reynolds numbers. Experiments have been conducted at Reynolds numbers of 175 and 355. The feedback loop consists of the hotwire probe, phase shifter available in LabVIEW, a power amplifier and electromagnetic actuators. In the presence of cylinder movement, the instantaneous flow field shows suppression of vortex shedding and reduction in velocity fluctuations. The time averaged flow field shows a reduction in the size of the recirculation region with both forced oscillations and feedback when compared to flow past a stationary cylinder. The drag coefficient of a cylinder with forced oscillations is 8% lower than the stationary, while, with feedback, the reduction is 5%.
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FULL TEXT (PDF): 
PDF icon arastrmx_153796_1_pp_110-117.pdf
  • 2
110-117
  • English

REFERENCES

References: 

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