Granular flows

Granular Flows

Those who have played with sand on the beach or with sugar in their kitchen are aware that a collection of solid grains can behave macroscopically like a liquid and flow. However, the description of this peculiar fluid still represents a challenge due to the lack of constitutive laws able to describe the rich phenomenology observed. In this paper we first review the properties of dry granular f...

Granular Flows

The epigrammatic quote by a French Nobel laureate is familiar to many in the field of granular mechanics and reflects a long-standing scientific fascination and practical interest. This is acknowledged by many others and summarized in the articles listed under Further Reading. As a general definition, we understand by granular medium a particle assembly dominated by pairwise nearest-neighbor in...

Instabilities in Granular Flows

The flow and handling of granular materials is of major importance to many industries. Yet despite efforts over several decades, the modeling of such flows has achieved only modest success. Dense gravity-driven flows in hoppers have been often modeled as elastic-plastic continua, for example. In this picture, the granular material flows as a plastic with a frictional yield condition, and deform...

Rapid Granular Flows

A granular material is a collection of a large number of discrete solid particles. Generally, the interstices between the particles are filled with a fluid such as air or water, and thus, technically, a granular flow is a multiphase process. However, if the particles are closely packed or if they are much denser than the interstitial fluid, the particles alone--and not the fluid or the fluid-pa...

Shallow granular flows