Effects of EGR on soot processes in n-dodecane spray combustion at high ambient temperature

This paper presents the numerical results of soot evolution in a constant volume chamber under different exhaust gas recirculation (EGR) levels at an ambient temperature of 1100 K by employing a two-equation soot model. The contribution and significance of each soot process on the net soot mass production are investigated.

The numerical setup is able to capture the experimentally observed monotonic trend of the soot mass, in which soot mass increases with decreasing oxygen (O2 ) level. The simulation results demonstrate that soot oxidation rates, particularly by hydroxyl radicals (OH), are the more dominating factors to the monotonic trend as compared to the inception and surface growth rates under different EGR.