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This work is a part of an extended investigation conducted by the authors to validate and improve a newly developed quasi-dimensional combustion model. The model has been initially applied on an old technology, naturally aspirated HSDI Diesel engine and the results were satisfying as far as performance and pollutant emissions (Soot and NO) are concerned. But since obviously further and more extended validation is required, in the present study the model is applied on a new technology, heavy-duty turbocharged DI Diesel engine equipped with a high pressure PLN fuel injection system. The main feature of the model is that it describes the air-fuel mixing mechanism in a more fundamental way compared to existing multi-zone phenomenological combustion models, while being less time consuming and complicated compared to the more accurate CFD models. The finite volume method is used to solve the conservation equations of mass, energy and species concentration.

The fundamental understanding of mixture formation and combustion process taking place in a DI diesel engine cylinder is an important parameter for engine design since they affect engine performance and pollutant emissions. Multi-dimensional CFD models are used for detailed simulation of these processes, but suffer from complexity and require significant computational time. The purpose of our work is to develop a new quasi-dimensional 3D combustion model capable of describing the air fuel mixing, combustion and pollutant formation mechanisms, on an engine cycle by cycle basis, needing reasonably low computational time compared to CFD ones, while describing in a more fundamental way the various processes compared to existing multi-zone phenomenological models. As a result, a number of problems associated with the application of multi-zone models are resolved.