Effect of a marginal inclination on pattern formation in a binary liquid mixture under thermal stress

TL;DR

This study examines how slight inclinations in a binary liquid layer under thermal stress influence pattern formation and flow dynamics, revealing a transition from shear-dominated to solutal convection regimes and unique drifting flow patterns.

Contribution

It demonstrates the significant impact of marginal inclinations on pattern formation and flow behavior in thermally-stressed binary liquids, highlighting a transition between shear and solutal convection.

Findings

Pattern formation is highly sensitive to small inclinations.

Transition from shear-dominated to solutal convection occurs with increasing Rayleigh number.

Drifting columnar flows emerge at the transition, forming a Super-Highway configuration.

Abstract

Convective motions in a fluid layer are affected by its orientation with respect to the gravitational field. We investigate the long-term stability of a thermally-stressed layer of a binary liquid mixture and show that pattern formation is strongly affected by marginal inclinations as small as a few milliradians. At small Rayleigh numbers the mass transfer is dominated by the induced large scale shear flow, while at larger Rayleigh numbers it is dominated by solutal convection. At the transition, the balance between the solutal and shear flows gives rise to drifting columnar flows moving in opposite directions along parallel lanes in a Super-Highway configuration.