Spiral Defect Chaos in Large Aspect Ratio Rayleigh-Bénard Convection
Spiral Defect Chaos in Large Aspect Ratio Rayleigh-Bénard Convection
Physical Review Letters 71, 2026 (1993).
Stephen W. Morris,
Eberhard Bodenschatz,
David S. Cannell,
and Guenter Ahlers
Department of Physics and Center for Nonlinear Science,
University of California Santa Barbara, CA 93106-9530
We report experiments on convection patterns in a cylindrical cell with
a large aspect ratio. The fluid had a Prandtl number ~ 1.
We observed a chaotic pattern consisting of many rotating spirals and other
defects in the parameter range where theory predicts that steady straight rolls
should be stable. The correlation length of the pattern decreased rapidly with
increasing control parameter so that the size of a correlated area became
much smaller than the area of the cell. This suggests that the chaotic
behavior is intrinsic to large aspect ratio geometries.
Submitted to Phys. Rev. Lett. May 12 1993.
PACS numbers: 47.20.Bp