Evaluation of drag force around bubble in an incipiently fluidized bed via a coupled CFD-DEM approach.

Detailed micromechanical analysis of an individual bubble injected into a three-dimensional incipiently fluidized bed is carried out by means of a coupled CFD-DEM approach. The distribution of interphase drag force vectors is consistent with the gas flow pattern based on the potential flow theory. The non-uniformity of drag force caused by bubbles is quantitatively analyzed. Moreover, a bubble-induced inhomogeneous coefficient is presented to assess the ensemble bubble impact. The effects of particle diameter and gas injection velocity are evaluated. The results reveal that the bubble negative effect on interphase drag force is strengthened by increasing the particle diameter and gas injection velocity. Unlabelled Image • Micromechanical analysis of an isolated bubble in a fluidized bed is studied. • The change of interphase drag caused by bubble force is evaluated. • Model prediction agrees well with experimental data. • Sensitivity of drag force around bubble to operating parameters is examined. [ABSTRACT FROM AUTHOR]