Structural Properties of Packings of Particles

Abstract

There is a wealth of literature on packed beds of particles, a study of which leads to the conclusion that it is difficult to meaningfully divide the great variety of known packs into different categories. The range of complexity of the structure of beds of particles is extremely wide: at one end of the spectrum are some natural soils, containing particles of various highly different shapes and sizes that are arranged in an infinite variety of irregular and unknown configurations, whereas at the other extreme of the scale of orderliness one finds the regular arrangements of monosized spheres. The latter are distinguished by a perfect order that facilitates a detailed description of their geometry. Owing to their great potential for analytical work, the structural properties of regular packings of equal spheres have been studied extensively. The results of these studies have been very interesting and enlightening, but sometimes they led to erroneous assumptions on the capillary and transport properties of irregular packs, containing particles of a wide range of different sizes and shapes. More recently, so-called random packs of monosized spheres have also been studied extensively, using statistical methods.