© 2017 The Authors. Published by Elsevier Ltd. Significant nanoparticle emission during the regeneration of Diesel Particulate Filters (DPFs) has been observed in experiments. A numerical reactive-flow model is coupled with a sectional particle method and phenomenological filtration model to describe the behavior of the DPF, and in particular the evolution of soot particle size distribution. The ability of the model to predict the pressure drop and flow profile in the DPF is critically assessed against experimental and simulated results from the literature. The capability to describe the impact of oxidative fragmentation on the size distribution of trapped particles is demonstrated. The model is shown to be able to qualitatively describe the decrease in average soot particle size during regeneration which will allow better prediction of particle number emissions.