Abstract
More stringent exhaust gas emission regulations will be introduced in the US, the EU and Japan in the near future up to 2010. To comply with such environmental regulations, although the aftertreatment system is expected to reduce exhaust emissions, the reduction of emissions from the cylinder of Diesel engines will become more important. Unfortunately, there are a lot of parameters which should be controlled during the combustion process in modern Diesel engines. Thus, engineering tools which are capable of carrying out numerical experiments under various engine operating conditions are desired to support the development of the clean diesel engines. This paper describes 3-dimensional computational fluid dynamics (CFD) studies based on the Reynolds averaged numerical simulation (RANS) approach combined with a detailed chemistry model simulating ignition, combustion and exhaust emission formation processes in a heavy duty Volvo D12C DI Diesel engine. The numerical tool used is the KIVA-3V code with a partially-stirred reactor (PaSR) turbulencechemistry interaction model integrated with a suite of spray sub-models. A Diesel oil surrogate mechanism describing oxidation of hydrocarbons, soot and NOx formations which consists of 305 elementary/global reactions and 70 chemical species was used in this study. In the simulations, the effects of injection timings on combustion and emission formation were investigated. As a result, the pressure and RoHR histories were predicted and found to be in good agreement with measured data. The extended tracking of -T computational cell values on a parametric dynamic -T map during ignition and combustion phases was also demonstrated.
Keywords:Heavy duty diesel engine, Combustion, Exhaust gas emissions, RNAS CFD Simulation, Detailed chemical reactions, Dynamic -T map