Dynamics of ferrofluidic flow in the Taylor-Couette system with a small aspect ratio Journal Article

Author(s): Altmeyer, Sebastian; Do, Younghae; Lai, Ying-Cheng
Article Title: Dynamics of ferrofluidic flow in the Taylor-Couette system with a small aspect ratio
Affiliation IST Austria
Abstract: We investigate fundamental nonlinear dynamics of ferrofluidic Taylor-Couette flow - flow confined be-tween two concentric independently rotating cylinders - consider small aspect ratio by solving the ferro-hydrodynamical equations, carrying out systematic bifurcation analysis. Without magnetic field, we find steady flow patterns, previously observed with a simple fluid, such as those containing normal one- or two vortex cells, as well as anomalous one-cell and twin-cell flow states. However, when a symmetry-breaking transverse magnetic field is present, all flow states exhibit stimulated, finite two-fold mode. Various bifurcations between steady and unsteady states can occur, corresponding to the transitions between the two-cell and one-cell states. While unsteady, axially oscillating flow states can arise, we also detect the emergence of new unsteady flow states. In particular, we uncover two new states: one contains only the azimuthally oscillating solution in the configuration of the twin-cell flow state, and an-other a rotating flow state. Topologically, these flow states are a limit cycle and a quasiperiodic solution on a two-torus, respectively. Emergence of new flow states in addition to observed ones with classical fluid, indicates that richer but potentially more controllable dynamics in ferrofluidic flows, as such flow states depend on the external magnetic field.
Journal Title: Scientific Reports
Volume: 7
ISSN: 20452322
Publisher: Nature Publishing Group  
Date Published: 2017-01-06
Start Page: Article number: 40012 (2017)
DOI: 10.1038/srep40012
Notes: Y.D. was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIP) (No. 2016R1A2B4011009). Y.C.L. was supported by AFOSR under Grant No. FA9550-15-1-0151. Y.C.L. would also like to acknowledge support from the Vannevar Bush Faculty Fellowship program sponsored by the Basic Research Office of the Assistant Secretary of Defense for Research and Engineering and funded by the Office of Naval Research through Grant No. N00014-16-1-2828.
Open access: yes (OA journal)