Investigation of soot aggregate formation and oxidation in compression ignition engines with a pseudo bi-variate soot model

In this work, a new pseudo bi-variate soot model is proposed for description of soot aggregate formation and oxidation in compression ignition engines. This soot model is a combination and modification of existing sub-models for soot nucleation, aggregation, surface growth and oxidation. The main advantage of this model over other bi-variate models is that it is able to provide a detailed insight into the soot aggregate formation processes with much less numerical difficulty. This new soot model has been implemented into a commercial computational fluid dynamics code and solved using an advanced method of moments. The resulting code is applied to investigate the formation of soot aggregates in a compression ignition engine operated under different conditions. Results suggest that this new pseudo bi-variate soot model is computationally cheap with little CPU cost induced by the treatment of the detailed soot particle dynamics. The model is able to correctly capture the emission trend for soot particles formed in compression ignition engines under different operating conditions. Detailed insight into the evolution of the soot aggregates in the engine cylinder can be provided.