Eur. Phys. J. E 37, 101 (2014)

http://dx.doi.org/10.1140/epje/i2014-14101-7

Inclined layer convection in a colloidal suspension with negative Soret coefficient at large solutal Rayleigh numbers

Matteo Italia, Fabrizio Croccolo, Frank Scheffold and Alberto Vailati

Convection in an inclined layer of fluid is affected by the presence of a component of the acceleration of gravity perpendicular to the density gradient that drives the convective motion. In this work we investigate the solutal convection of a colloidal suspension characterized by a negative Soret coefficient. Convection is induced by heating the suspension from above, and at large solutal Rayleigh numbers (of the order of 10^7–10^8) convective spoke patterns form. We show that in the presence of a marginal inclination of the cell as small as 19mrad the isotropy of the spoke pattern is broken and the convective patterns tend to align in the direction of the inclination. At intermediate inclinations of the order of 33mrad ordered square patterns are obtained, while at inclination of the order of 67mrad the strong shear flow determined by the inclination gives rise to ascending and descending sheets of fluid aligned parallel to the direction of inclination.