Title: Some new methodologies in continuum modeling of granular flow

Author (Invited): Ken Kamrin, MIT

Abstract:

Granular media are common in industry, the natural world, and our day-to-day lives, but have been historically resistant to modeling. While grain-by-grain discrete element methods (DEM) exist, these are often far too costly at the length-scales of real-life problems. Instead, this talk progressively develops continuum-based tools with the aim of realistic but computationally tractable full-scale flow simulation. We begin with a discussion of dry granular rheology and its essential ingredients. We provide a brief discussion of what sorts of problems can be solved accurately with a basic granular flow model, and discuss a meshless numerical method, the Material Point Method (MPM), which can be used to simulate these models up to huge deformations. We then discuss new ways to exploit this capability to tackle more advanced problems. In problems where regions of the flow may be too complex for the basic continuum model, we extend the framework into a DEM-continuum hybrid simulation method, which allows the problem domain to be split adaptively into MPM and DEM subdomains so as to provide grain-scale precision only where needed.