Abstract
Feedback control of vortex shedding from a circular cylinder in a uniform flow at moderate Reynolds numbers is studied experimentally with the cylinder subjected to feedback cylinder oscillations in cross-flow direction. The cylinder oscillation is digitally phase shifted with respect to the shedding vortex and is controlled by velocity feedback from the shear layer of the cylinder wake. Possible attenuation of vortex shedding is demonstrated by hot-wire measurements of the flow field and its mechanisms are studied by simultaneous data sampling and flow visualization with the smoke wire method and a laser-sheet illumination technique. Measurement results reveal substantial reduction in the fluctuating reference velocity at the optimum phase control. Flow visualization study indicates that the shear layer roll-up and the eventual vortex formation are dynamically attenuated under the control which results in a modification of the near wake.
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Abbreviations
- A :
-
amplitude of cylinder oscillation
- D :
-
cylinder diameter
- E u :
-
power spectrum function for fluctuating velocity u′
- \(f\) :
-
frequency
- R :
-
radius of circular cylinder
- t :
-
time
- u :
-
streamwise mean velocity
- u′:
-
streamwise fluctuating velocity
- U :
-
streamwise mean velocity of main flow
- u r :
-
mean reference velocity
- u′ r :
-
fluctuating reference velocity
- u′ rf :
-
fluctuating reference velocity after filtering
- y c :
-
cylinder displacement
- x, y, z :
-
coordinates from the cylinder center (Fig. 1)
- α:
-
feedback coefficient
- φ :
-
phase lag
References
Bearman PW (1984) Vortex shedding from oscillating bluff bodies. Ann Rev Fluid Mech 16: 195–222
Filler JR et al. (1991) Response of the shear layers seperating from the circular cylinder to small amplitude rotational oscillations. J Fluid Dyn 231: 481–499
Ffowcs-Williams JE; Zhao BC (1989) The active control of vortex shedding. J Fluids Struct 3: 115–122
Fujisawa N; Warui HM (1994) Active control of vortex shedding by cross-flow oscillation of a circular cylinder in a uniform flow. Proc. FLUCOME, Toulouse, France. 113–118
Griffin OM; Hall MS (1991) Review-vortex shedding lock-on and flow control in bluff body wakes. ASME J Fluids Eng 113: 526–537
King R (1977) A review of vortex shedding research and its application. Ocean Eng 4: 141–171
Sarpkaya T (1979) Vortex-induced oscillations-A selected review. J Appl Mech 46: 241–258
Roussopoulos K (1993) Feedback control of vortex shedding at low Reynolds numbers. J Fluid Mech 248: 267–296
Toebes GH (1969) The unsteady flow and wake near an oscillating cylinder. J Basic Eng D91: 493–505
Tokumaru PT; Dimotakis PE (1991) Rotary oscillation control of a cylinder wake. J Fluid Mech 22: 77–90
Unal MF; Rockwell D (1987) On vortex formation from a cylinder. Part 2. Control by splitter-plate interference. J Fluids Mech 190: 513–529
Warui HM; Fujisawa N (1994) Flow visualization of vortex shedding from an actively controlled circular cylinder with cross-flow oscillations. Asian Symp on Visualization 3: 193–198
Wilson JF; Tinsley JC (1989) Vortex load reduction: Experiments in optimal helical strake geometry for rigid cylinders. ASME J Energy Resources Technol 111: 72–76
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The authors would like to express thanks to Professor K. Nagaya for his advice for designing electromagnetic actuators in the present experiments.
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Warui, H.M., Fujisawa, N. Feedback control of vortex shedding from a circular cylinder by cross-flow cylinder oscillations. Experiments in Fluids 21, 49–56 (1996). https://doi.org/10.1007/BF00204635
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DOI: https://doi.org/10.1007/BF00204635