Sensitivity Analysis of Key Parameters in LES-DEM Simulations of Fluidized Bed Systems Using Generalized Polynomial Chaos

In applications involving fine powders and small particles, the accuracy of numerical simulations, particularly those employing the Discrete Element Method (DEM) to predict granular material behavior, can be significantly affected by uncertainties in critical parameters. These uncertainties include the coefficients of restitution for particle-particle and particle-wall collisions, viscous damping coefficients, and other related factors. In this study, we use stochastic expansions based on point-collocation non-intrusive polynomial chaos to perform a sensitivity analysis of a fluidized bed system. We treat four key parameters as random variables; each assigned a specific probability distribution over a designated range. This uncertainty is propagated through high-fidelity Large Eddy Simulation (LES)-DEM simulations to statistically quantify its impact on the results. To effectively explore the four-dimensional parameter space, we analyze a comprehensive database comprising over 1,200 simulations. Notably, our findings reveal that variations in the particle and wall Coulomb friction coefficients have a more pronounced influence on streamwise particle velocity than variations in the particle and wall normal restitution coefficients.