A new method for validation of a CFD–DEM model of gas–solid fluidized bed

A new method is developed for validation of the simulation of a gas–solid fluidized bed via computational fluid dynamics and discrete element method (CFD–DEM). Chaotic attractors of two independent pressure signals (evaluation series of the CFD–DEM model and reference time series of measured pressure fluctuations) were compared in the state-space domain using the S-statistic to consider the null hypothesis (the same dynamics). To prove the capability of the proposed method, the S-statistic was tested on several series of experimental pressure fluctuations, measured at both similar and different dynamic conditions. The method was able to determine the similarities and differences in the measured pressure signals. It was shown that the whole pressure signal of the CFD–DEM passed the test. Results of the CFD–DEM and the experimental data were then compared in various ranges of frequencies. In order to achieve this objective, a combination of the S-statistic and wavelet transform was used which showed that the CFD–DEM attractors were obtained from the same dynamic features as the experiments at high and low frequencies corresponding to micro- and macro-structures.

► Applicability of the S-test for validation of the CFD–DEM code.
► Dominant contribution of the macro-structures in the model and experiment.
► Overestimate of the energy of the macro-structures in the model.
► Prediction of large bubble characteristic and particles motion in the model.
► Weak determination of clusters and small bubbles behavior in the model.