Stochastic Synchronization of the Wall Turbulence
Instantaneous amplitude and phase concept emerging from analytical signal formulation is applied to the wavelet coefficients of streamwise velocity fluctuations in the buffer layer of a near wall turbulent flow. Experiments and direct numerical simulations show both the existence of long periods of inert zones wherein the local phase is constant. These regions are separated by random phase jumps. These behaviours are reminiscent of phase synchronization phenomena observed in stochastic chaotic systems. The lengths of the constant phase inert (laminar) zones reveal a type-I intermittency behaviour. The observed phenomena are related to the footprint of coherent structures convecting in the low buffer layer that synchronizes the wall turbulence.
KeywordsChaotic System Direct Numerical Simulation Coherent Structure Phase Synchronization Chaos Synchronization
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