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

Effect of changes in particle size on the hydrodynamics of gas-solid fluidized beds through wall vibration

“…The second order Daubechies wavelet (DB2) was chosen as the mother wavelet for analysis of the vibration signals since it resulted in the minimum residual for a given order and scale among other mother wavelets tested [31,32]. The Shannon entropy was used to obtain the required level of decomposition and it was found that 9 levels of decomposition are enough for extracting all required information from the signal [33]. The ranges of approximate frequency band of A j (t) and D j (t), based on the sampling frequency (25 kHz) in this study, are summarized in Table 2.…”

Characterization of flow regimes in fluidized beds by information entropy analysis of pressure fluctuations

“…Therefore, it has been widely used to characterize the flow regimes and to determine the transition points of flow regimes and reveal the transition mechanism to a certain extent. Recently, a number of characterization analysis methods [23][24][25][26][27][28][29][30][31] and classification criteria [32,33] have been proposed based on the analysis of fluctuation signals. In this study, characteristic analysis of fluctuation signals is adopted for the characterization and classification of flow regimes.…”

Characterization of pressure fluctuations from a gas–solid fluidized bed by structure density function analysis

“…Multi-scale characteristics of pressure fluctuations in time were responsible for the multi-fractality of the data (Ghasemi et al, , 2011b. Tahmasebpour et al (2013) reported that the effects of smaller (micro-and meso-) structures on the flow initially decreased with increasing gas velocity, and then increased after passing through a transition velocity. To improve understanding of the dynamics of gas-solid flow, it is important to study the multi-scale behavior of the flow.…”