A joint experimental and numerical project has been initiated at Virginia Tech to study the effect of ozone on diesel soot precursors. This thesis is the first stage of the numerical part of the project, and contains a study of the effect of the different ozone levels on diesel soot precursors. This numerical study is executed via the use of two computer programs, Senkin, and PSR. An idealistic model of the diesel engine was used in both analyses. The numerical studies were done at three different engine speeds, 1500, 2000, 2500 RPM and eight different levels of ozone. Studies were performed with ozone introduced with the intake air and with the fuel. Eleven product species, which include dominant soot precursors such as acetylene (C2H2) and the propargyl radical (C3H3), were examined and evaluated during this experiment. After analyzing both simulations, the PSR predictions were not useful since it omits the existence of temperature and species gradients. The PSR analysis was used as a preliminary model to get an overall idea of combustion pollutant formation and predicted the exit soot precursor concentrations were unaffected by any ozone addition. However, the Senkin analysis predicted the ozone injection did have the potential to reduce the formation of soot precursors. The Senkin analysis predicted more realistic results and therefore it is believed to yield the correct conclusion. However, it was suggested that an additional program, such as KIVA3, be utilized to predict a more practical view of the chemical kinetic behavior of ozone and its effect on the diesel engine. / Master of Science