Sensitivity analysis of kinetic theory of granular flow (KTGF) and mixture models in terms of involved elemental parameters for two-phase gas-solid flow

Abstract

Probing into the multiscale essence and nonlinear interactions of gas-solid flows whether in natural or industrial scale have continuously been evoking challenges in flow physics and modeling approaches. Although there are capabilities within the test bench experiments and empirical formulas to define or predict the flow characteristics in two-phase systems, the flow pattern would be still unknown, and here is where the numerical approaches thrive. Since, the corresponding non-linear equation system developed to predict the behavior of two-phase flows is intrinsically complex and makes the numerical solutions time-consuming, in this article, the sensitivity analysis of two well-known models based on the Euler-Euler approach, namely KTGF and Mixture models, is conducted in terms of continuous/dispersed shear stress and solid pressure on the accuracy, stability, and duration of solution. In the KTGF model, granular viscosity is particularly most influential term; while in the Mixture model, the numerical solution profoundly depends on the continuous phase viscosity. Moreover, it is perceived that the existence of solid pressure as a diffusive source term is consequential for the stability in the modeling process, and in high values of dispersed volume fraction, its impact on the flow behavior is distinguishable.