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A Diesel spray and combustion model has been connected to the CFD-code StarCD. The paper provides an overview of the submodels implemented, which account for liquid core atomization, droplet secondary break-up, droplet collision, impingement, turbulent dispersion and evaporation. Auto-ignition and combustion is described by the Representative Interactive Flamelet (RIF)-model. This concept allows to separate the fluid dynamics from the chemical processes with their significantly smaller timescales, and enables to account for a sufficiently large number of chemical species and reactions in order to predict pollutant formation such as NOx and soot. The CFD-predictions are extensively compared to experimental data. Spray model validation cases focus on the distribution of droplet sizes, velocities and fuel vapor in free and impinging sprays.

The aggressive reduction of future diesel engine NOx emission limits forces the heavy- and light-duty diesel engine manufacturers to develop means to comply with stringent legislation. As a result, different exhaust emission control technologies applicable to NOx have been the subject of many investigations. One of these systems is the NOx adsorber catalyst, which has shown high NOx conversion rates during previous investigations with acceptable fuel consumption penalties. In addition, the NOx adsorber catalyst does not require a secondary on-board reductant. However, the NOx adsorber catalyst also represents the most sulfur sensitive emissions control device currently under investigation for advanced NOx control. To remove the sulfur introduced into the system through the diesel fuel and stored on the catalyst sites during operation, specific regeneration strategies and boundary conditions were investigated and developed.