Numerical Investigation of Soot Formation in Diesel Jet Flame Using Detailed Kinetic Model(Diesel Engines, Combustion Modeling I)

Abstract

This work investigates the soot formation process in diesel jet flame using a detailed kinetic soot model implemented into the KIVA-3V multidimensional CFD code. The numerical model is based on the KIVA code which is modified to use CHEMKIN as the chemistry solver using Message Passing Interface (MPI). This allows for the chemical reactions to be simulated hi parallel on multiple CPUs. The detailed soot model used is based on the method of moments, which begins with fuel pyrolysis, followed by the formation of polycyclic aromatic hydrocarbons, their growth and coagulation into spherical particles, and finally, surface growth and oxidation of the particles. The model can describe the spatial and temporal characteristics of soot formation processes such as soot precursors distributions, nucleation rate and surface reaction rate. Simulation results show that the soot particles are formed to surround the soot precursor formation region and to extend downstream. It was also found that the dominant soot growth process differs by the region in the fuel jet. The particle inception is fast around the central region of the jet, and acetylene surface reaction rate becomes higher toward the periphery of the jet.