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The objective of this work was to improve the accuracy of the combustion speed estimation in rich fuel condition (φ ≻ 1.2) as in case of Gasoline Direct Injection (GDI) engine. During rich fuel mixture combustion, the accuracy of calculation of laminar burning velocity deteriorates because of not considering the flame stretch. In the present study, the unstable flame due to the imbalance of the mass diffusion and the temperature diffusion of the fuel (Lewis Number (Le) ≺ 1.0) was modeled. The laminar burning speed model was developed by considering the stretch. It was applied with three-dimensional combustion simulation tools together with the Universal Coherent Flamelet Model (UCFM), a flame propagation model. The model has shown the capability to reproduce the heat generation (heat release rate) at high accuracy in comparison with experimental data.

The objective of this work was to improve the accuracy of the combustion speed estimation in rich fuel condition (φ ≻ 1.2) as in case of Gasoline Direct Injection (GDI) engine. During rich fuel mixture combustion, the accuracy of calculation of laminar burning velocity deteriorates due to not considering the flame stretch. In the present study, the unstable flame was formed due to the imbalance of the mass diffusion and the temperature diffusion of the fuel (Lewis Number (Le) ≺1.0) was modeled. The laminar burning speed model was developed by considering the stretch. It was applied with three-dimensional combustion simulation tools together with the Universal Coherent Flamelet Model (UCFM), a flame propagation model. The model has shown the capability to reproduce the heat generation (heat release rate) at high accuracy in comparison with experimental data.

In response to the emissions standards for diesel engines, it is essential to have separate aftertreatment devices for controlling the specific tailpipe emissions like HC, CO, NOx, and particulate matter. An advanced diesel exhaust aftertreatment system consists of channel-flow catalytic converters such as diesel oxidation catalyst (DOC), selective catalyst reduction (SCR) and wall-flow diesel particulate filters (DPF) each with discrete functions. Because of this multi-component aftertreatment system configuration, there are an increase in system complexity, development time and cost for doing experiments in order to evaluate various options and find the optimum aftertreatment system architecture. The objective of this work is the development and application of an integrated aftertreatment system model including DOC, SCR, DPF and all connecting pipes. The study includes the baseline system performance, i.e.