Suppressing vortex generation in ferrofluidic Couette flow via alternating magnetic fields
We illustrate how an alternating magnetic field can restrict and suppress the generation of vortex formation in ferrofluidic Couette flow. Therefore, the initial rotating outer cylinder (inner cylinder at rest) is brought to an abrupt stop, which results in the generation of more complex vortex dyna...
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2023 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/399432 |
| Acceso en línea: | https://hdl.handle.net/2117/399432 https://dx.doi.org/10.1016/j.euromechflu.2023.11.007 |
| Access Level: | acceso abierto |
| Palabra clave: | Magnetic fluids Taylor vortices Taylor-Couette flow Ferrofluid Suppressing vortex generation Alternating magnetic field Non-linear dynamics Camps magnètics Vòrtexs de Taylor Àrees temàtiques de la UPC::Física |
| Sumario: | We illustrate how an alternating magnetic field can restrict and suppress the generation of vortex formation in ferrofluidic Couette flow. Therefore, the initial rotating outer cylinder (inner cylinder at rest) is brought to an abrupt stop, which results in the generation of more complex vortex dynamics in the system, evolving out of the initially fully laminar flow regime. The generated vortex flow structures appear to be axisymmetric Taylor vortices. Different stages during the spin-down process are described and characterised through dynamic quantities, such as the kinetic energy, cross-flow energy, and angular velocity flux. The presence of an alternating magnetic field modifies these dynamics during the spin-down, which is mainly dominated by the modulation amplitude of the alternating field. While moderate modulation amplitudes tend to minimize the vortex formation, i.e. weaken the flow dynamics, large modulation amplitudes suppress any vortex formation. The driving frequency only has a minor effect in general, but may allow to select between different flow pattern within the process. |
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