Predicting granular flow experiments: continuum modeling with a length-scale
David Henann (Brown University), Ken Kamrin (MIT)
Multiscale Mechanics of Particulate Media
Mon 10:45 - 12:15
Sayles 105
Dense granular materials display a complicated set of flow properties, which differentiate them from ordinary fluids. In particular, slowly-flowing granular media form clear, experimentally-robust features; most notably, shear bands, which can have a variety of possible widths and which decay non-trivially into the surrounding quasi-rigid material. Despite the ubiquity of granular flows, no model has been developed that captures or predicts these complexities, posing an obstacle in industrial and geophysical applications. We present a three-dimensional constitutive model for well-developed, dense granular flows aimed at filling this need. The key ingredient of the theory is a grain-size-dependent nonlocal rheology -- inspired by efforts for emulsions -- in which flow at a point is affected by both the local stress as well as the flow in neighboring material. With a single new material parameter, we show that the model is able to quantitatively predict experimental dense granular flows in an array of different geometries.