Aggregation and fragmentation in granular mixtures
Anna Bodrova, Moscow State University
Granular materials, such as gravel sand or different types of powders, are ubiquitous in nature and widely used in industry. Rarified granular systems, where the volume of a solid phase is small as compared to the total volume, are termed as granular gases. In the Earth conditions these may be obtained by placing granular matter into a container with vibrating or rotating walls, applying electrostatic or magnetic forces etc. Extraterrestrial granular gases are also common. Many astrophysical objects, like protoplanetary discs, Planetary Rings and interstellar dust clouds contain granular gases as one of the important component.
Granular materials represent a polydisperse mixture of grains of different mass and size. We investigate size and kinetic energy distribution in granular mixtures, arising due to interplay of aggregation and fragmentation of granular particles. We also discuss application of our theory to dense planetary rings and compare our results with data, available from the observations.