Experimental analysis of fluid-dynamic chaotic signals in oscillating containers

The experimental investigation of sloshing flows inside oscillating containers is performed by using methods and algorithms typical of dynamical system theory. The delay time technique is used for analyzing dynamical behaviours by using long time histories of one velocity component measured by LDA. The amplitude of oscillations is used to obtain a control parameter (the Froude number). Spectral density, phase space plots, correlation dimension, entropy and Lyapunov exponents are evaluated at different oscillation regimes. At low oscillation amplitudes the evolution of the system is nearly linear. For increasing amplitudes the computations show that, chaotic conditions, characterized by a low number of degrees of freedom, are obtained. By changing the shape of the container both the quasiperiodicity (Ruelle and Takens) and the period doubling (Feigenbaum) transition scenarios have been clarified