A granular material is a conglomeration of discrete solid, macroscopic particles characterized by a loss of energy whenever the particles interact (the most common example would be friction when grains collide). The constituents that compose granular material are large enough such that they are not subject to thermal motion fluctuations. Thus, the lower size limit for grains in granular material is about 1 μm. On the upper size limit, the physics of granular materials may be applied to ice floes where the individual grains are icebergs and to asteroid belts of the Solar System with individual grains being asteroids.
Some examples of granular materials are snow, nuts, coal, sand, rice, coffee, corn flakes, fertilizer, and bearing balls. Research into granular materials is thus directly applicable and goes back at least to Charles-Augustin de Coulomb, whose law of friction was originally stated for granular materials. Granular materials are commercially important in applications as diverse as pharmaceutical industry, agriculture, and energy production.
Powders are a special class of granular material due to their small particle size, which makes them more cohesive and more easily suspended in a gas.
The soldier/physicist Brigadier Ralph Alger Bagnold was an early pioneer of the physics of granular matter and whose book The Physics of Blown Sand and Desert Dunes remains an important reference to this day. According to material scientist Patrick Richard, "Granular materials are ubiquitous in nature and are the second-most manipulated material in industry (the first one is water)".
In some sense, granular materials do not constitute a single phase of matter but have characteristics reminiscent of solids, liquids, or gases depending on the average energy per grain. However, in each of these states, granular materials also exhibit properties that are unique.
Granular materials also exhibit a wide range of pattern forming behaviors when excited (e.g. vibrated or allowed to flow).
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A granular material is a conglomeration of discrete solid, macroscopic particles characterized by a loss of energy whenever the particles interact (the most common example would be friction when grains collide). The constituents that compose granular material are large enough such that they are not subject to thermal motion fluctuations. Thus, the lower size limit for grains in granular material is about 1 μm.
Application des principales catégories de procédés de production.Modèles physiques élémentaires décrivant le comportement des principaux procédés de production.Compréhension de base des aspects éc
This course provides an introduction to particle-based methods for the numerical resolution of partial differential equations describing continuum phenomena or for the simulation of particulate flows.
The effectiveness of submerged synthetic aquatic vegetation on removal of colloids from flowing water was investigated to explore retention of particulate nonpoint source pollutants in aquatic systems
2022
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Water significantly influences the mechanical behaviour of all granular materials but none as much as hygroscopic amorphous particles. With sufficiently high water content, particles can swell, agglom
Cemented granular materials are abundant in nature and are often artificially produced. Their macroscopic behaviour is driven by small-scale material processes, which are generally classified as: grai