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Rayleigh-Benard Convection in Large-Aspect-Ratio Domains

M. R. Paul·K-H. Chiam·M. C. Cross·P. F. Fischer
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Abstract

The coarsening and wavenumber selection of striped states growing from random initial conditions are studied in a non-relaxational, spatially extended, and far-from-equilibrium system by performing large-scale numerical simulations of Rayleigh-Bénard convection in a large-aspect-ratio cylindrical domain with experimentally realistic boundaries. We find evidence that various measures of the coarsening dynamics scale in time with different power-law exponents, indicating that multiple length scales are required in describing the time dependent pattern evolution. The translational correlation length scales with time as $t^{0.12}$, the orientational correlation length scales as $t^{0.54}$, and the density of defects scale as $t^{-0.45}$. The final pattern evolves toward the wavenumber where isolated dislocations become motionless, suggesting a possible wavenumber selection mechanism for large-aspect-ratio convection.

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M. R. Paul, K-H. Chiam, M. C. Cross, P. F. Fischer. 2004-03-08. Rayleigh-Benard Convection in Large-Aspect-Ratio Domains. https://doi.org/10.1103/physrevlett.93.064503

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