Experiments on vibrated granular materials : waves, convection and segregation

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.