ABSTRACT
Droplet or particle size can be a very important parameter governing the flow of a dispersed two-phase mixture. For this reason, it is useful to have a basic knowledge of the statistical parameters relating to particle size distributions. For spherical particles or droplets, a measure of the size is the diameter. For nonspherical particles, an equivalent diameter must be selected to quantify the size (see Chapter 10). The most general definition of the spread of the particle size distribution is
monodisperse or polydisperse. A monodisperse distribution is one in which the particles are close to a single size, whereas polydisperse suggests a wide range of particle sizes. An approximate definition of a monodisperse distribution is one for which the standard deviation is less than 10% of the mean particle diameter.
