FPM-SE: A numerical model for dense gas–solid flows with large non-spherical object

Abstract

In dense gas–solid flows such as that in fluidized bed gasifier, large non-spherical solid objects co-exist with small bed particles. During the fluidization, the large non-spherical objects experience complex forces depending on their shape, size, and orientation and a diverse and complex dynamics emerges. Here, we present a numerical model for dense gas–solid flows with large non-spherical objects. The proposed model named FPM-SE is based on the combination of Fictitious Particle Method (FPM) for large size differences and Super-Ellipsoid (SE) model for various shapes. We also perform experiments using a Lagrangian sensor system to investigate the influence of object shape on its sinking/floating motions in a gas-fluidized bed. We observe that non-sphericity facilitates the floating of large objects. Not only FPM-SE reasonably captures the experimental observations but it also demonstrates a typical sinking–staying in the bottom–floating behavior with an orientational change of large non-spherical objects.