The coarsening of a polydisperse set of N particles is
studied by computer simulation. The main steps
of the simulation are the following: generation of a set of
N (typically 20 000) particles according to an
a priori model of the particle size distribution, and subsequent
transfers of molecules from one particle
to another according to predetermined growth rules. As an
application, we consider the Ostwald ripening
process. In this case, the exchange of molecules between small and
large particles is governed by Kelvin's
equation. The evolution of the average particle radius and of the
size distribution is studied both in the
stationary and nonstationary regimes. The typical characteristics
of the stationary regime predicted by
the Lifshitz−Slyozov−Wagner theory are recovered. For a more
realistic initial log-normal size distribution,
it was found that during an increase in average radius of about a
factor of 4.3, the stationary regime was
not yet attained. Results are also reported for the combined
effects of Ostwald ripening and membrane
resistance.