Hostname: page-component-8448b6f56d-wq2xx Total loading time: 0 Render date: 2024-04-20T04:22:36.208Z Has data issue: false hasContentIssue false

Spatially localized binary-fluid convection

Published online by Cambridge University Press:  20 July 2006

ORIOL BATISTE
Affiliation:
Departament de Física Aplicada, Universitat Politècnica de Catalunya, Barcelona, Spain
EDGAR KNOBLOCH
Affiliation:
Department of Physics, University of California, Berkeley, CA 94720, USA
ARANTXA ALONSO
Affiliation:
Departament de Física Aplicada, Universitat Politècnica de Catalunya, Barcelona, Spain
ISABEL MERCADER
Affiliation:
Departament de Física Aplicada, Universitat Politècnica de Catalunya, Barcelona, Spain

Abstract

Multiple states of spatially localized steady convection are found in numerical simulations of water–ethanol mixtures in two dimensions. Realistic boundary conditions at the top and bottom are used, with periodic boundary conditions in the horizontal. The states form by a mechanism similar to the pinning region around a Maxwell point in variational systems, but are located in a parameter regime in which the conduction state is overstable. Despite this the localized states can be stable. The properties of the localized states are described in detail, and the mechanism of their destruction with increasing or decreasing Rayleigh number is elucidated. When the Rayleigh number becomes too large the fronts bounding the state at either end unpin and move apart, allowing steady convection to invade the domain. In contrast, when the Rayleigh number is too small the fronts move inwards, and eliminate the localized state which decays into dispersive chaos. Out of this state spatially localized states re-emerge at irregular times before decaying again. Thus an interval of Rayleigh numbers exists that is characterized by relaxation oscillations between localized convection and dispersive chaos.

Type
Papers
Copyright
© 2006 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)