(375a) Direct Numerical Simulations of Hydrodynamic Forces on Assemblies of Non-Spherical Particles

Historically, the non-spherical particle fluidization simulations are simplified with spher- ical particle assumption. However, there is a large mismatch between the simulation results and experiments. Our work focuses on building a multi-scale modelling procedure for fluidization of non-spherical particles. This work particularly focuses on the direct numerical simulation aspect of the multi-scale modelling. In this work, particle resolved flows are performed around static assemblies of random orientations of non-spherical particles using a multi-relaxation-time lattice Boltzmann method.

The parameter space for assemblies of spherical particles are relatively simpler. They are just limited to different Reynolds numbers (Re) and solids-volume fractions (ǫs). However for non-spherical particles, it is also needed to know the mutual orientation of the particles in the simulation domain and also their mean orientation with respect to the flow direction. Therefore, we propose two parameters S1 and S2 to measure the mutual orientations of the particles and also the incident angle φ with respect to the incoming flow. Additional to the drag, we also investigate the dependencies of lift and torques as function of Re, ǫs, S1, S2 and φ. From the data obtained, we propose accordingly the correlations for drag, lift and torque coefficients, which can be used to simulate larger scale simulations of non-spherical particles fluidization.