Special flow model for passive particle transport considering internal noise

Abstract

We have generalized the semi-analytic approach of special flow to the description of flows of passive particles taking into account internal noise. The model is represented by a series of recurrence relations. The recurrence relations are constructed by numerically solving the Langevin equations in the presence of a random force, for an ensemble of passive particles during transport through a secluded cell. This approach allows us to estimate the transit time dependence near stagnation points for fluid elements carried by the flow. Such estimates are obtained for the most important types of stagnation points. It is shown that macroscopic transport of an ensemble of particles through such a lattice is possible only when internal noise is taken into account. For Gaussian and non-Gaussian noise at low intensity the transit time has one peak, which is a consequence of the existence of vortices of one stagnation point. Increase of noise intensity leads to slowing down of particle transport.