TY - JOUR
T1 - Exotic wakes of an oscillating circular cylinder
T2 - how singles pair up
AU - Hourigan, Kerry
N1 - Publisher Copyright:
© The Author(s), 2021. Published by Cambridge University Press.
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/7/5
Y1 - 2021/7/5
N2 - Fascinating wake vortex patterns emerge when a circular cylinder is forced to vibrate laterally to a uniform fluid flow, deviating from the well-known Kármán vortex street and first reported by Williamson & Roshko (J. Fluids Struct., vol. 2, 1988, pp. 355-381). The two rows of single vortices (2S mode) can suddenly transition to a row of paired vortices and a row of single vortices (P+S mode) as the forcing amplitude is increased. Further increase in amplitude finds another sudden jump back to the 2S mode. Through a series of elegant and carefully crafted numerical simulations, Matharu et al. (J. Fluid Mech., vol. 918, 2021, A42) determine that the transitions occur via bifurcations, but that underlying these observed 'jumps', a continuous evolution of the vortex street between the modes is seen along unstable branches connecting the two modes. As the Reynolds number decreases from 100, bistability and the P+S mode are eventually suppressed.
AB - Fascinating wake vortex patterns emerge when a circular cylinder is forced to vibrate laterally to a uniform fluid flow, deviating from the well-known Kármán vortex street and first reported by Williamson & Roshko (J. Fluids Struct., vol. 2, 1988, pp. 355-381). The two rows of single vortices (2S mode) can suddenly transition to a row of paired vortices and a row of single vortices (P+S mode) as the forcing amplitude is increased. Further increase in amplitude finds another sudden jump back to the 2S mode. Through a series of elegant and carefully crafted numerical simulations, Matharu et al. (J. Fluid Mech., vol. 918, 2021, A42) determine that the transitions occur via bifurcations, but that underlying these observed 'jumps', a continuous evolution of the vortex street between the modes is seen along unstable branches connecting the two modes. As the Reynolds number decreases from 100, bistability and the P+S mode are eventually suppressed.
KW - bifurcation
KW - computational methods
KW - vortex shedding
UR - http://www.scopus.com/inward/record.url?scp=85109476942&partnerID=8YFLogxK
U2 - 10.1017/jfm.2021.492
DO - 10.1017/jfm.2021.492
M3 - Article
AN - SCOPUS:85109476942
VL - 922
JO - Journal of Fluid Mechanics
JF - Journal of Fluid Mechanics
SN - 0022-1120
M1 - F1
ER -