In their recent JPhysD Topical Review, author Renaud Delannay and colleagues review a range of experimental and numerical modeling techniques for geophysical granular and particle laden flows. Such flows consist of solid-fluid mixtures driven by gravity and
In their recent JPhysD Topical Review, author Renaud Delannay and colleagues review a range of experimental and numerical modeling techniques for geophysical granular and particle laden flows. Such flows consist of solid-fluid mixtures driven by gravity and propagate in an ambient fluid over generally complex topographies. Professor Delannay explains why investigating these phenomena is so important:
The study of natural granular flows on Earth and on other planets is an important subject both in terms of understanding, modeling and prediction, in relation to the processes of erosion and deposition, but also for societal issues (on Earth) in the context of natural hazards. Knowledge obtained from laboratory experiments is the basis for addressing natural flows, which are often very complex (consisting of grains with a wide variety of sizes, unsteady, transporting fluids, etc.). The mechanisms of triggering these flows are also interesting (volcanism, earthquakes or others), as well as the subsequent events (tsunamis, modification of deposits, etc.).
The study of subsequent events is of particular importance here; since the geologist sees most of the time only the final state (direct observations of flows are rare, difficult or dangerous). He thus has to solve an inverse problem consisting in inferring the dynamics of the flow from the characteristics of the deposit. It is a very difficult exercise, especially since the processes involved in these geophysical flows are very complex and many parameters come into play. The classical simpli