(379h) Collision Dynamics and Impaction of Inelastic Nano Particles

Analysis of flow of granular material is useful in designing storage of food grains, ores, and coal to pharmaceutical powders and  to digital printing. High definition digital imaging is enabled in printers by using small micron and nano toner particles. Use of small particles in a container gives rise to complex particulate flow as small particles tend to aggregate and large particles break on normal and oblique collisions with each other or with walls of the container. Particulate solids undergo brittle- ductile transition which depends on the size of a particle and its shape, its inelastic behavior and strain rates under which it is deformed.

Particulate flow can result in jamming which has been analyzed using Lattice- Boltzmann (LB) or DEM (Discrete Element Methods) on deformation from collisions during hydrodynamic forces in fluid-particle flows, An elastic-plastic model is developed for particle collisions during a particulate flow that depends on particle radius, incident particle speed and yield stress of the material. The model predictions are compared with experimental data on particles prepared by reactive extrusion and subjected to time dependent deformation in a contained cavity.