Manifestation of the stochastic resonance in submerged jets under an acoustic action

A phenomenon that is similar to the well-known stochastic resonance in nonlinear oscillators but is caused by the turbulence in a circular submerged jet under a harmonic acoustic action, rather than by noise, is considered. It is shown that, at a fixed distance from the nozzle, a variation of the initial turbulence level leads to a non-monotonic variation of the wave amplitude at the frequency of the acoustic action, namely, to the appearance of an amplitude maximum at a certain level of the initial turbulence. The qualitative explanation of the phenomenon consists in that the initial turbulence acts on the system in a way similar to that of external noise: it changes the effective parameters of the system and, in particular, shifts the spectral maxima, which is equivalent to a change in a certain “eigenfrequency.” Such a change in the effective parameters of the jet leads to a phenomenon similar to the stochastic resonance.