Saturation of the response to stochastic forcing in two-dimensional backward-facing step flow: A self-consistent approximation

Abstract

Noise amplifier flows, such as the flow above a backward facing step, are characterized by a large amplification to external stochastic perturbations. These perturbations, however, quickly loose their randomness: the response to inlet white noise undergoes a selective process promoting a response structure with an approximately single frequency active in the whole domain.