The Spatio-Temporal Structure of Spiral-Defect Chaos
The Spatio-Temporal Structure of Spiral-Defect Chaos
Physica D, 97, 164 (1996).
Stephen W. Morris
Department of Physics and Erindale College,
University of Toronto, 60 St. George St., Toronto, Ontario, Canada M5S 1A7.
Eberhard Bodenschatz
Department of Physics and
Laboratory of Atomic and Solid State Physics,
Cornell University
Ithaca, New York 14853.
David S. Cannell and Guenter Ahlers
Department of Physics and Center for Nonlinear Science,
University of California
Santa Barbara, California 93106-9530
We present a study of the recently discovered spatially-extended chaotic state known as spiral-defect chaos, which occurs in low-Prandtl-number, large-aspect-ratio Rayleigh-Bénard convection. We employ the modulus squared of the space-time Fourier transform of time series of two-dimensional shadowgraph images to construct the structure factor S(k,omega ). This analysis is used to characterize the average spatial and temporal scales of the chaotic state. We find that the correlation length and time can be described by power-law dependences on the reduced Rayleigh number e. These power laws have as yet no theoretical explanation.
PACS numbers: 47.20.-k,47.52.+j,47.54.+r,47.27.-i
