Three-dimensional instabilities in a discretely heated annular flow: onset of spatio-temporal complexity via defect dynamics
The transition to three-dimensional and unsteady flow in an annulus with a discrete heat source on the inner cylinder is studied numerically. For large applied heat flux through the heater (large Grashof number Gr), there is a strong wall plume originating at the heater that reaches the top and form...
| Autores: | , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2014 |
| 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:2117/24190 |
| Acceso en línea: | https://hdl.handle.net/2117/24190 https://dx.doi.org/10.1063/1.4881435 |
| Access Level: | acceso abierto |
| Palabra clave: | Taylor vortices Benjamin-Feir instability Taylor-Couette flow Parity-breaking bifurcation Unsteady natural-convection Benjamin-feir instability Inhomogeneous systems Rectangular cavity Wave interactions Rotating waves Regime Side Dinàmica de fluids Turbulència Àrees temàtiques de la UPC::Física |
| Sumario: | The transition to three-dimensional and unsteady flow in an annulus with a discrete heat source on the inner cylinder is studied numerically. For large applied heat flux through the heater (large Grashof number Gr), there is a strong wall plume originating at the heater that reaches the top and forms a large scale axisymmetric wavy structure along the top. For Gr approximate to 6 x 109, this wavy structure becomes unstable to three-dimensional instabilities with high azimuthal wavenumbers m similar to 30, influenced by mode competition within an Eckhaus band of wavenumbers. Coexisting with some of these steady three-dimensional states, solution branches with localized defects break parity and result in spatio-temporal dynamics. We have identified two such time dependent states. One is a limit cycle that while breaking spatial parity, retains spatio-temporal parity. The other branch corresponds to quasi-periodic states that have globally broken parity. (C) 2014 AIP Publishing LLC. |
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