1.1 The Discrete Method

In the discrete method, the particle population is discretized into a finite number of size intervals. This approach has the advantage of computing the particle size distribution (PSD) directly. This approach is also particularly useful when the range of particle sizes is known a priori and does not span more than two or three orders of magnitude. In this case, the population can be discretized with a relatively small number of size intervals and the size distribution that is coupled with fluid dynamics can be computed. The disadvantage of the discrete method is that it is computationally expensive if a large number of intervals is needed.