Soret driven convection in a colloidal solution heated from above at very large solutal Rayleigh number
Abstract
Convection in a colloidal suspension with a large negative separation ratio is studied experimentally by heating from above. Shadowgraph observation at very large solutal Rayleigh numbers are reported as a function of time. Fast relaxation oscillations are reported for the root mean square value of the shadowgraph intensity. While pure fluids exhibit a transition to turbulent convection for Rayleigh number of about 10^6, stable spoke-pattern planform with up and down columnar flows are observed up to solutal Rayleigh numbers of the order of 10^9. It is suggested that the surprising stability of the planform against turbulence is due to nonlinear focusing arising from the concentration dependence of the diffusion coefficient.
Keywords
Cite
@article{arxiv.cond-mat/0210053,
title = {Soret driven convection in a colloidal solution heated from above at very large solutal Rayleigh number},
author = {R. Cerbino and A. Vailati and M. Giglio},
journal= {arXiv preprint arXiv:cond-mat/0210053},
year = {2009}
}
Comments
10 pages, 4 figures