Self-similarity of density and velocity profiles in a 2D hopper flow of elliptical particles: Discrete element simulation

Abstract

Two-dimensional discharge flow of elliptical particles with different aspect ratios from a silo is investigated by using discrete element simulation. The measured flow rate of the particles is well fitted via Beverloo's law. The flow rate shows a monotonic decrease with increasing aspect ratio. The density and velocity profiles of particles at the outlet were systematically measured. At an identical outlet size, the speed of particles through the aperture decreases with increasing aspect ratio. The velocity profiles in all cases follow the same definite self-similar law and are in good agreement with the reported experimental results, thereby showing compatibility with the free fall arch postulation. The density profiles show obvious self-similar feature and can be fitted conveniently by using a fractional power law. Based on these observations and the results of the previous work, the flow rate for elliptical particles is calculated and is in agreement with the simulated results.