Numerical Investigation of Vortex Shedding Control Behind a Cylinder with Swinging Thin Plates

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Bagherzadeh Chehreh, Babak | 2016

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Type of Document: M.Sc. Thesis
Language: Farsi
Document No: 49120 (08)
University: Sharif University of Technology
Department: Aerospace Engineering
Advisor(s): Javadi, Khodayar; Tayyebi Rahni, Mohammad
Abstract:
Von-Karman vortex shedding is a transient aerodynamic instability which occurs in laminar flows over a bluff body in a certain condition. When this phenomenon occurs, vortices take form on upper and lower parts of the bluff body and begin to shed into an oscillatory manner affecting a significant part of the flow domain. This research focuses on Karman vortex shedding control by using two thin oscillating splitter plates. Length ratio of plates to cylinder diameter is 1 (L⁄D=1) and plates are attached at ±55 degrees (trigonometric angle). Plates are forced to oscillate at different ratios of natural vortex shedding frequencies (0.75, 1, 1.25, 1.5 and 2) for diffenet amplitudes. Simulations were conducted for Reynolds numbers 200, 250 and 300 by numerically solving Navier-Stokes equations using finite Volume method. Our results show that in certain configurations the oscillatory nature of side force (lift force) is completely suppressed. The effects of splitter plates oscillation on Drag force, flow behavior and vortex shedding frequency are also presented
Keywords:
Aerodynamic Instability ; Strouhal Number ; Von-Karman Vortex ; Pressure Fluctuation ; Vortex Shedding ; Circular Cylinder

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