Synthesis of Pd nanoparticles by evaporation of Pd vapor generated by inductive heating of a metal ingot followed by rapid condensation in a jet aerosol Row condenser (JAFC) is simulated. Computational fluid dynamics (CFD) elucidate the detailed temperature and velocity profiles in the complex geometry of the JAFC. A model is developed by interfacing simple jet correlations for temperature and velocity with monodisperse aerosol dynamics. It is shown that coagulation is a dominant process for particle growth. The model predictions for the average particle diameter are within a factor of two from the experimental data without any adjustable parameters.