Characterization of chaotic dynamics - I: dynamical invariants of sheared polymer solutions

Stress measurements as a function of time in aqueous polymer solutions show the presence of sustained dynamic features for identifiable steady shear r egions, The analysis of post-transient time-series data. reveals the presen ce of low-dimensional chaotic dynamics. Interestingly, the results obtained from different types of polymer solutions, viz., thermosensitive polymers and biopolymers, show similar complex dynamical features and suggest that m echanisms responsible are common. The experimental data have been analyzed with a view to characterizing the strange attractor in terms of invariant m easures such as the correlation, embedding, Lyapunov dimensions and entropy . (C) 2001 Elsevier Science Ltd. All rights reserved.