Sensitivity analysis of the variational model for the particulate expansion of fluidized beds

Abstract

Fluidization experiments were performed by using spherical and non-spherical particles to examine the sensitivity of the variational model to three input parameters: Umf, εmf and Ut. Several correlations for Umf, εmf and Ut were tested and the results were compared with the experimental values. The variational model’s ability to predict the bed expansion (in the form of U=f(ε)) and the interphase drag coefficient was investigated by varying the three input variables by ±20% compared with their experimental values. The variational model for the bed expansion showed the greatest sensitivity to changes in the εmf values. The overestimated values of εmf resulted in underestimating U(ε), and likewise, the underestimated values of εmf resulted in overestimating U(ε). The variational model’s sensitivity to changes in the Umf values is also important. Contrary to εmf, overestimating the values of Umf resulted in overestimating U(ε). The model’s least sensitivity was to the Ut value variation, which, if varied by ±20% compared with their experimental values, had a negligible effect on the prediction quality. This study aims to examine the sensitivity of the variational model to Umf, Ut and εmf values obtained from various correlations, in the absence of experimental values.