RT Journal Article
T1 Imperfect O(2) symmetry in counter-rotating split-cylinder  ow
A1 Gutiérrez-Castillo, Paloma
A1 Lopez, J. M.
K1 Dinámica de fluidos
AB The effect of a small imperfection in the counter-rotating split-cylinder flow is studied numerically. The defect is characterized by a smallparameter  , corresponding to the difference in the magnitude of rotations in each half of the cylinder. With the two half cylinders not rotatingexactly in counter rotation, the O(2) symmetry of the exact counter-rotating case (invariance to azimuthal rotations as well as to an involutionconsisting of reflections about the mid-plane composed of reflections about any meridional plane) is weakly broken. This small defectresults in relevant variations in the flow. For slow rotations (characterized by a small Reynolds number), the system remains axisymmetricwith the imperfection only breaking the reflection symmetry about the cylinder half-height. At larger Reynolds numbers, in the absence ofthe imperfection, axisymmetry is broken resulting in steady states with azimuthal wavenumber m. When axisymmetry is broken in the presenceof the imperfection, a background rotation is introduced. Depending on the case and the level of imperfection, either rotating waves orslow-fast dynamics with mean background rotations are found instead. The interaction between azimuthal wavenumbers m¼2 and 3 playsa crucial role in the flow. The flow is analyzed in detail, varying   from a very small value of 0.01%, typical of a natural imperfection in anexperimental setup, to higher values corresponding to forced symmetry breaking. The ramifications of the imperfection on various solutionstates found in the exact counter-rotating case for a fixed aspect ratio are investigated
PB Physics of Fluids
YR 2022
FD 2022-01-05
LK https://hdl.handle.net/10630/35556
UL https://hdl.handle.net/10630/35556
LA eng
NO P. Gutierrez-Castillo and Juan M. Lopez, Imperfect O(2) symmetry in counter-rotating split-	cylinder flow .Physics of Fluids, Vol 34, 014105, 2022
NO ASU Research Computing facilities. This work wassupported in part by the U.S. National Science Foundation throughGrant No. 1929139.
DS RIUMA. Repositorio Institucional de la Universidad de Málaga
RD 2 mar 2026