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: U_mf, ε_mf and U_t. Several correlations for U_mf, ε_mf and U_t 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 ε_mf values. The overestimated values of ε_mf resulted in underestimating U(ε), and likewise, the underestimated values of ε_mf resulted in overestimating U(ε). The variational model’s sensitivity to changes in the U_mf values is also important. Contrary to ε_mf, overestimating the values of U_mf resulted in overestimating U(ε). The model’s least sensitivity was to the U_t 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 U_mf, U_t and ε_mf values obtained from various correlations, in the absence of experimental values.

Keywords:

• Fluidization
• variational model
• bed expansion
• particle-fluid interphase drag coefficient
• model sensitivity analysis

Additional information

Funding

The financial support of the Serbian Ministry of Education, Science and Technological Development (Project ON172022) is gratefully acknowledged.