Experiments on deaerating granular flows and implications for pyroclastic flow mobility

Granular mass flows and Coulomb’s friction in shear cell experiments: Implications for geophysical flows

[1] Granular mass flows of rock fragments are studied in the lab by means of a high-speed video camera at 2000 frames per second. These granular flows are generated using beds of pumice fragments positioned on a rough rotating disk, whose angular velocity is controlled by a motor. The experimental apparatus allows an understanding of the arrangement of the particles in granular mass flows with ...

Granular Flow Simulations and Experiments for the Food Industry

Granular media are omnipresent in the food industry, whether as raw materials, intermediate or final products. While a lot has been done already in modelling food processes dealing with liquids, solid and gases, very little existed until now in granular flow modelling. The present thesis takes up the challenge of producing realistic granular simulations via DEM and validating them experimentall...

Channel Flows of Granular Materials and Their Rheological Implications

Flow rule, self-channelization, and levees in unconfined granular flows.

Unconfined granular flows along an inclined plane are investigated experimentally. During a long transient, the flow gets confined by quasistatic banks but still spreads laterally towards a well-defined asymptotic state following a nontrivial process. Far enough from the banks a scaling for the depth averaged velocity is obtained, which extends the one obtained for homogeneous steady flows. Clo...

Experiments and simulations of a gravitational granular flow instability.

An instability is observed as a layer of dense granular material positioned above a layer of air falls in a gravitational field [Phys. Rev. Lett. 99, 048001 (2007)]. A characteristic pattern of fingers emerges along the interface defined by the grains, and a transient coarsening of the structure is caused by a coalescence of neighboring fingers. The coarsening is limited by the production of ne...