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Title: Critical dynamics at a Hopf bifurcation to oscillatory Rayleigh-Benard convection

Journal Article · · Phys. Rev. A; (United States)

The steady-state and dynamic properties of the transition to oscillatory convection in a low-Prandtl-number fluid, dilute /sup 3/He in superfluid /sup 4/He, are presented. Critical slowing down is observed and characterized by a phenomenological Landau-Hopf equation in analogy with equilibrium mean-field critical phenomena. In contrast to the onset of classical time-independent Rayleigh-Benard convection, where appreciable rounding is typically observed, there is no measurable rounding at the oscillatory onset down to a reduced Rayleigh number of 3 x 10/sup -4/. Possible reasons for this are discussed. Different functional singularities are observed for the rms amplitudes of the fundamental and first harmonic spectral components of the oscillation. Finally, the Prandtl-number dependence of the parameters of the dynamics is presented.

Research Organization:
Los Alamos National Laboratory, University of California, Los Alamos, New Mexico 87545
OSTI ID:
6058708
Journal Information:
Phys. Rev. A; (United States), Vol. 33:3
Country of Publication:
United States
Language:
English