The onset of deterministic chaos in gas-solids fluidization

A brief introduction is given to the analysis of chaotic time series of experimental systems. This type of time sequence analysis is used to investigate the onset of chaotic behavior in a 10 cm ID gas-solids fluidized bed of Geldart-B particles in the vicinity of minimum fluidization. Pressure fluctuation data are analyzed to characterize the behavior in terms of dimension and entropy. It is found that just above minimum fluidization a transition regime exists where dimension and entropy increase and decrease before the fully developed bubbling state is reached. The experimental results agree qualitatively very well with simulation results of a particle array model.