Increasing flow complexity in time-dependent modulated ferrofluidic Couette flow
We present numerical simulations of ferrofluidic Couette flow in between counter-rotating cylinders with a spatially homogeneous magnetic field but subject to time-periodic modulation. Such a modulation can lead to a significant inner Reynolds number (Rei ) enhancement for primary bifurcating soluti...
| Author: | |
|---|---|
| Format: | article |
| Publication Date: | 2022 |
| Country: | España |
| Institution: | Universitat Politècnica de Catalunya (UPC) |
| Repository: | UPCommons. Portal del coneixement obert de la UPC |
| Language: | English |
| OAI Identifier: | oai:upcommons.upc.edu:2117/371812 |
| Online Access: | https://hdl.handle.net/2117/371812 https://dx.doi.org/10.1134/S0015462822030016 |
| Access Level: | Open access |
| Keyword: | Navier-Stokes equations Magnetic fluids Computational fluid dynamics Numerical and Computational Physics, Simulation Navier–Stokes equations Ferrofluids Modulated magnetic field Bifurcation scenario Time-periodic forcing Direct numerical simulation Equacions de Navier-Stokes Dinàmica de fluids computacional Àrees temàtiques de la UPC::Física |
| Summary: | We present numerical simulations of ferrofluidic Couette flow in between counter-rotating cylinders with a spatially homogeneous magnetic field but subject to time-periodic modulation. Such a modulation can lead to a significant inner Reynolds number (Rei ) enhancement for primary bifurcating solutions, for either helical or toroidal flow structures. Moreover, the external introduced modulation frequency renders the different solutions to step up one level in the hierarchy of complexity. Fixed point solutions become limit cycles and limit cycles become 2-tori. Moreover, for sufficiently strong modulation amplitudes of the magnetic field stability can be exchanged between primary bifurcating spiral and ribbon solutions, both appearing at a common threshold. In addition, a stable bifurcation branch with direct connection of ribbon and Taylor vortices via wavy Taylor vortices is found. |
|---|