Weakened Vortex Shedding from a Rotating Cylinder
Authors: Sharul S. Dol
An experimental study of the turbulent near wake of a rotating circular cylinder was made at a Reynolds number of 2000 for velocity ratios, λ between 0 and 2.7. Particle image velocimetry data are analyzed to study the effects of rotation on the flow structures behind the cylinder. The results indicate that the rotation of the cylinder causes significant changes in the vortex formation. Kármán vortex shedding pattern of alternating vortices gives rise to strong periodic fluctuations of a vortex street for λ < 2.0. Alternate vortex shedding is weak and close to being suppressed at λ = 2.0 resulting a distorted street with vortices of alternating sense subsequently being found on opposite sides. Only part of the circulation is shed due to the interference in the separation point, mixing in the base region, re-attachment, and vortex cut-off phenomenon. Alternating vortex shedding pattern diminishes and completely disappears when the velocity ratio is 2.7. The shed vortices are insignificant in size and forming a single line of vortex street. It is clear that flow asymmetries will deteriorate vortex shedding, and when the asymmetries are large enough, total inhibition of a periodic street occurs.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1088430Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF
 Barnes, F.H. (2000). Vortex shedding in the wake of a rotating circular cylinder at low Reynolds number, J. Physics, Vol. 33, pp. 141.
 Massons, J., Ruiz, X. and Diaz, F. (1989). Image processing of the near wakes of stationary and rotating cylinders, Journal of Fluid Mechanics, Vol. 204, pp. 167.
 Tanaka, H. and Nagano, S. (1973). Study of flow around a rotating circular cylinder, Bull. JSME, Vol. 16, pp. 234.
 Swanson, W.M. (1961). The Magnus effect: A summary of investigations to date, Journal of Basic Engineering, Vol. 83, pp. 461.
 Diaz, F., Gavalda, J., Kawall, J.G., Keffer, J.F. and Giralt, F. (1983). Vortex shedding from a spinning cylinder, Physics of Fluids, Vol. 26, pp. 3454.
 Badr, H.M., Coutanceau, M., Dennis, S.C.R. and Menard, C. (1990). Unsteady flow past a rotating circular cylinder at Reynolds number 103 and 104, Journal of Fluid Mechanics, Vol. 220, pp. 459.
 Chang, C.C. and Chern, R.L. (1991). Vortex shedding from an impulsively started rotating and translating circular cylinder, Journal of Fluid Mechanics, Vol. 233, pp. 265.
 Chew, Y.T., Cheng, M. and Luo, S.C. (1995). A numerical study of flow past a rotating circular cylinder using a hybrid vortex scheme, Journal of Fluid Mechanics,Vol. 299, pp. 35.
 Dol, S.S., Kopp, G.A. and Martinuzzi, R.J. (2008).The suppression of periodic vortex shedding from a rotating circular cylinder, Journal of Wind Engineering and Industrial Aerodynamics,96, pp.1164–1184
 West, G.S. and Apelt, C.J. (1982). The effects of tunnel blockage and aspect ratio on the mean flow past a circular cylinder with Reynolds number between 104 and 105, Journal of Fluid Mechanics, Vol. 114, pp. 361.
 Laneville, A. (1990). Turbulence and blockage effects on two dimensional rectangular cylinders, Journal of Wind Engineering and Industrial Aerodynamics,Vol. 33, pp. 11.
 Coleman, H.W. and Steele, W.G. (1989). Experimental Uncertainty Analysis for Engineers, Wiley, New York.
 Roshko, A. (1954). On the drag and shedding frequency of twodimensional bluff bodies, NACA TN No. 3169.
 Zdravkovich, M.M. (1997). Flow around circular cylinders: a comprehensive guide through flow phenomena, experiments, applications, mathematical models, and computer simulations, Vol. 1: Fundamentals, Oxford University Press, Oxford, UK.
 Zdravkovich, M.M. (2003). Flow around circular cylinders: a comprehensive guide through flow phenomena, experiments, applications, mathematical models, and computer simulations, Vol. 2: Applications, Oxford University Press, Oxford, UK.
 Dol, S.S. (2004). The suppression of periodic vortex shedding from a rotating circular cylinder. M.E.Sc. Thesis. Western Ontario University, Ontario, Canada.
 Bailey, S.C.C., Kopp, G.A. and Martinuzzi, R.J. (2003). Vortex shedding from a square cylinder near a wall, Journal of Turbulence, Vol. 3, pp. 1.
 Saffman, P.G. and Schatzman, J.C. (1981). An inviscid model for the vortex-street wake, Journal of Fluid Mechanics, Vol. 122, pp. 467.