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

Takuya Tsuji, Yuya Sakamoto, Shusaku Harada, Koshi Uemoto, Jun Oshitani, Kimiaki Washino, Toshitsugu Tanaka, Hirokazu Kajiwara, Kei Matsuoka

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.

Chemical Engineering Science

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