Induced pretransitional Rayleigh-Bénard convection

Abstract

We study the properties of subcritical Rayleigh-Bénard rolls induced by a triggering velocity applied to one side of a fluid layer maintained in controlled subcritical conditions. The induced rolls are spatially damped exponentially with increasing distance from the position of the triggering velocity. We point out a remarkable critical behavior of a characteristic penetration length $\xi (\xi ={\xi }_0{\epsilon }^{-\nu })$. The values of $\nu =0.50\mathrm{}\pm 0.02$ and ${\xi }_0=(0.38\mathrm{}\pm 0.01)d$ are in perfect agreement with those calculated according to the Landau-Hopf model.