On the Applicability of Low-Dimensional Models for Convective Flow Reversals at Extreme Prandtl Numbers

Abstract

Constructing simpler models, either stochastic or deterministic, for exploring the phenomenon of flow reversals in fluid systems is in vogue across disciplines. Using direct numerical simulations and nonlinear time series analysis, we illustrate that the basic nature of flow reversals in convecting fluids can depend on the dimensionless parameters describing the system. Specifically, we find evidence of low-dimensional determinism in flow reversals occurring at zero Prandtl number, whereas we fail to find such signatures for reversals at infinite Prandtl number. Thus, even in a single system, as one varies the system parameters, one can encounter reversals that are fundamentally different in nature. Consequently, we conclude that a single general low-dimensional deterministic model cannot faithfully characterize flow reversals for every set of parameter values.

9 pages, 4 figures

References in corpus (7)

• Comparison between two and three dimensional Rayleigh-Bénard convection
• A simple mechanism for the reversals of Earth's magnetic field
• Dynamics of reorientations and reversals of large scale flow in Rayleigh-Benard convection
• A model of diffusion in a potential well for the dynamics of the large-scale circulation in turbulent Rayleigh-Benard convection
• Flow reversals in turbulent convection with free-slip walls
• Magnetic field reversals and long-time memory in conducting flows
• Revisiting Evidence of Chaos in X-ray Light Curves: The Case of GRS 1915+105