Characterisation of the particle-wall frictional forces in pseudo-2D fluidized beds using DEM

In this work a numerical study of a pseudo-2D gas fluidized bed is carried out using the MFIX-DEM code with a twofold aim. The first aim is to check whether the DEM code reproduces the overall experimental value of the frictional force of the walls on the particles in the pseudo-2D bed in bubbling regime, previously measured by Hernandez-Jimenez et al. (2013) by means of a global force balance in the bed. The second aim of this work is to perform a local study of the wall-particle frictional forces, using the results of the DEM simulations. The results showed that the force balance proposed by Hernandez-Jimenez et al. (2013) is consistent with the DEM simulations, corroborating that the particle-wall overall force can be considered equal to the velocity of the centre of mass times a global particle-wall interaction coefficient, c. Besides, it was found that the most probable value of the local coefficient c in the DEM simulations is similar to the global value experimentally obtained. As expected, the DEM results showed that this particle-wall interaction coefficient, c, increases with the particle-wall friction coefficient. Coincidence between simulations and experiments is maximum if an angle of internal friction very close to 30 degrees is considered in the DEM particle-wall interaction.

Characterisation of the particle-wall frictional forces in pseudo-2D fluidized beds using DEM Articles