EVIDENCE OF WEAK CHAOS WITHIN PLUG-SLUG TRANSITION IN HORIZONTAL 2-PHASE FLOW

Intermittent behaviour has been observed in gas-liquid flows in a hori zontal pipe and a weak sign of deterministic chaos has been diagnosed within a transition from plug to slug flow. The analysis has been perf ormed on the basis of an algorithm which exploits the concept of short -term predictability of chaotic motions. The method is completely non- parametric and works whatever the distribution function of the data po ints may be. The weak sign of chaos is in contrast with the Lorenz-typ e systems (strong chaos) and supports the idea of Kolmogorov about irr egular motion in hydrodynamical systems.