2011 Interdisciplinary Summer School: Granular Flows

Segregation in Rapid Flows (Continuum and DEM)

Christine Hrenya, University of Colorado

Granular flows are ubiquitous in nature and industry. Oftentimes the granular material is composed of particles of different sizes. This nonuniform particle size distribution (PSD) not only changes the bulk behavior of the flowing grains, but also leads to phenomena with no monodisperse counterpart - for example, species segregation. In this talk, the focus will be on rapidly flowing grains, or flows in which the particle contacts can be approximated as instantaneous and binary in nature. Furthermore, PSD's characterized by a continuous distribution of particle sizes (e.g., lognormal) will be emphasized. The basics and pros/cons of continuum and DEM modeling of such flows will be discussed. These topics will be illustrated via an ongoing research project targeted at the prediction of regolith ejection during lunar landings.