Abstract:
A granular material is a collection of solid particles or grains such that most of
the particles are in contact with at least some of their neighboring particles. The
terms granular materials, bulk solids, particulate solids and powders are used interchangeably in the literature. They occur in all shapes and sizes ranging from
sand, gravel, food grains, seeds, sugar, coal, and cement to large planetry rings
and asteroids. Granular materials are commonly encountered in nature as well as
in various chemical processing industries. With reference to the chemical industry,
Ennis et. al. note that about 40% of the value added is linked to particle technology [1]. Similarly, more than 50% of all products sold are either granular in form
or involve granular materials in their production [2]. In spite of their importance,
the mechanics of granular flow is not well understood at present. However, some
progress has been made during the last few decades.