Calibration of particle interactions for discrete element modeling of powder flow

An ASTM B213 standard Hall Flowmeter Funnel experiment was conducted for Ti 6–4 powder particles and simulated utilizing a discrete element method approach implemented in the LIGGGHTS package. Particle interactions were described with a modified simplified Johnson–Kendall–Roberts theory that includes adhesion as a function of the particle surface free energy. Experimental data for the powder particle size distribution were used as input for the simulations. Adjustable parameters, such as cohesion energy density, coefficient of restitution and dynamic friction, were tuned to match the general shape of the experimentally obtained particle pile. Geometrical properties of the simulated powder pile, including its diameter, height and inside/outside slope angles, were computed and compared with the experimental results where available. Local particle size distributions for different areas within the pile (top vs. bottom) were obtained, indicating the dominance of larger particles at the top of the pile, akin to the Brazil nut effect.