Abstract
The behaviour of dense assemblies of dry grains submitted to continuous
shear deformation has
been the subject of many experiments and discrete particle simulations. This
paper is a collective work carried
out among the French research group GDR Milieux Divis´es. It proceeds
from the collection of results
on steady uniform granular flows obtained by di erent groups in six di erent
geometries both in experiments
and numerical works. The goal is to achieve a coherent presentation of the
relevant quantities to be
measured i.e. flowing thresholds, kinematic profiles, e ective friction,
etc. First, a quantitative comparison
between data coming from di erent experiments in the same geometry enforces
the robust features in each
case. Second, a transversal analysis of the data across the di erent configurations,
allows us to identify the
relevant dimensionless parameters, the di erent flow regimes and to propose
simple interpretations. The
present work, more than a simple juxtaposition of results, underlines the
richness of granular flows and
enhances the open problem of defining a single rheology.