Rayleigh-Bénard convection is investigated for Prandtl numbers Ï from 0.3 to 1.0 by using various pure gases and binary gas mixtures. The onset of spiral-defect chaos (SDC) moves to smaller values of [Formula presented] is the Rayleigh number and [Formula presented] its critical value) as Ï decreases. The measurements suggest that large-scale mean flows, which are expected to be stronger at smaller Ï, play an important role in the spontaneous generation of SDC.SDC can occur and fully develop in the regime dominated by the Soret effect.
ASJC Scopus subject areas
- Physics and Astronomy(all)