(254e) CFD-DEM simulation of the onset of fluidization for large particles in a bed of fine sand
AIChE Annual Meeting
2021
2021 Annual Meeting
Particle Technology Forum
Honorary Session for John Grace (Invited Talks)
Wednesday, November 17, 2021 - 1:35pm to 1:55pm
In this study, we aim at predicting the Umf of large and light biomass particles (objects) mixed with fine sand particles (fines), with the help of coupling the computational fluid dynamics (CFD) and the discrete element method (DEM). To this end, fine particles were primarily simulated using the coarse-grained CFD-DEM, in which a group of fine particles was lumped into a larger numerical parcel. In the conventional CFD-DEM, the CFD cell size is usually 3-4 times larger than the bed particles. This ratio cannot be held when there is a substantial size difference between the bed components as it significantly increases the computational error. To address this issue, we adopted the diffusion-based averaging method and mapped the solid concentration and solid velocity of the object into the CFD cells. The capability of the adopted numerical approach for predicting the motion of the object in a bed of fine particles was verified by comparing the upward and downward velocities of the object with the corresponding experimental data. Further simulations are in progress to predict the Umf of the objects varying in size and density in a bed of sand particles.