Characterization of various structures in gas-solid fluidized beds by recurrence quantification analysis

作     者：M.Tahmasebpour R.Zarghami R.Sotudeh-Gharebagh N.Mostoufi 

作者机构：Multiphase Research Systems LaboratoryOil and Gas Centre of ExcellenceSchool of Chemical EngineeringCollege of EngineeringUniversity of Tehran 

出 版 物：《Particuology》 (颗粒学报（英文版）)

年 卷 期：2013年第11卷第6期

页      面：647-656页

核心收录：

学科分类：081704[工学-应用化学] 08[工学] 0817[工学-化学工程与技术] 081701[工学-化学工程] 

主　　题：Fluidization Recurrence quantification analysis Multi scale Pressure fluctuations Chaos Hydrodynamics 

摘      要：Gas-solid fluidized beds are widely considered as nonlinear and chaotic dynamic systems. Pressure fluc- tuations were measured in a fluidized bed of 0.15 m in diameter and were analyzed using multiple approaches： discrete Fourier transform （DFT）, discrete wavelet transform （DWT）, and nonlinear recur- rence quantification analysis （RQA）. Three different methods proposed that the complex dynamics of a fluidized bed system can be presented as macro, meso and micro structures. It was found from DFT and DWT that a minimum in wide band energy with an increase in the velocity corresponds to the transition between macro structures and finer structures of the fluidization system. Corresponding transition veloc- ity occurs at gas velocities of 0.3, 0.5 and 0.6 m]s for sands with mean diameters of 150, 280 and 490/~m, respectively. DFT, DWT, and RQA could determine frequency range of0-3.125 Hz for macro, 3. ! 25-50 Hz for meso, and 50-200 Hz for micro structures. The RQA showed that the micro structures have the least periodicity and consequently their determinism and laminarity are the lowest. The results show that a combination of DFT, DWT, and RQA can be used as an effective approach to characterize multi-scale flow behavior in gas-solid fluidized beds.