Inferring liquid chaotic dynamics in bubble columns using CARPT

Experiments carried out to study the liquid displacements in bubble columns via the computer automated radioactive particle tracking technique are analyzed by means of Lagrangian and qualitative dynamics tools. The Lagrangian approach yields the detailed motion sequences of the tracer as entrained by the fast ascending bubbles or by the liquid flow alongside the column walls. The qualitative dynamics tools, on the other hand, provide prima facie corroboration of chaos in liquid motion based on an analysis of the volume-averaged Kolmogorov entropy and the mutual information function. Other features of the chaotic motion, the reconstructed attractors and the radial and axial distributions of Lyapunov exponents, are noted. Variations in the liquid hydrodynamics due to changes in column diameter and operating pressure are inspected. By increasing pressure the attractor's correlation dimension and the information loss rate decrease, whereas the liquid flow path is dramatically affected. (C) 2001 Published by Elsevier Science Ltd.