  The dynamics of the particle-size distribution (PSD) of the polydispersed
fuel is important for evaluation of the combustion process. In this paper we
unfold the mystery of the dynamics represented by the PSD and gain new insight
for the droplet behavior during the ignition process. A simplified model of the
polydispersity is used for describing the system near the linear region, which
evolves time depended function which describes the PSD. We examine the PSD
uctuation in time of the initial PSD described by the experimental as well as
the Rosin-Rammler, Nukiyama-Tanasawa and the gamma distributions
approximations. The results shows that the during the ignition process the
droplets radii decrease as expected, yet the number of the smaller droplet
increase in inverse proportion to the radius. An important novel result
visualized by the graph, is the average radius of the droplets which first
increases for shot time following by decreasing. The last result show the
maximum of average radius is not located at the beginning of the process as
expected. The algorithm presented here is superior to the parcel approach,
since it can be applied for any approximation of the PSD, with negligible
computation time.
