Stochastic resonance for dispersion in oscillatory flows

Abstract

We discuss the dispersion of particles suspended in time-periodic flows. It is found that this dispersion becomes maximal if the stochastic process describing the intrinsic random motion of the suspended particles is in "resonance" with the time-periodic flow. Furthermore, the dispersion coefficient is found to be proportional to the spectrum of the stochastic process, evaluated at the frequency of the flow. The dispersion is calculated for several cases of interest, including a two-layer, non-Markovian model and field flow fractionation.