Collisional forces and flow characteristics of a stream of falling particles in interaction with a large stationary sphere.

An experimental characterization of a stream of falling particles impacting a stationary sphere is conducted in which the diameter of the sphere is two orders of magnitude larger than the diameter of a single particle. A novel method is applied for measuring the instantaneous collisional force between the sphere and dilute particle stream using a strain gauge-based force sensor in combination with high-speed imaging. The objective of this work is to understand the effects of particle velocity, size, and density on the collisional force when there is a significant size difference between two interacting granular phases. Additionally, discrete element method (DEM) simulations are conducted. The DEM closely represents the experimental behavior in low particle velocities, whereas the discrepancies between the experimental and computational data increase with the stream velocity corresponding to the falling distance. The presented experimental methodology and data can be applied for the development and validation of numerical modeling of particle collisions. [Display omitted] • Novel experimental method is presented for measuring contact force with a strain gauge in dilute particle flows. • Collisional (drag) force of falling particles impacting a large sphere is measured and modeled. • The effects of particle velocity, size, and density are studied on collisional forces. • The characterization of falling particles is performed using high-speed video image analysis. [ABSTRACT FROM AUTHOR]