| The primary objective of this study is to improve the spray and combustion modeling of internal combustion engines using dynamic mesh refinement. The first part of the study used advanced spray models with a dynamic mesh refinement scheme to simulate atomization of gasoline and diesel sprays. Traditionally gasoline sprays and diesel sprays were simulated using different models due to their different characteristics. This study was able to use the same set of models without adjustments in model constants and obtain good agreement between experimental and simulation results. The model was also used to simulate a direct-injection gasoline engine with realistic geometry. The present spray model with dynamic mesh refinement algorithm was shown to predict the spray structure and liquid penetration accurately with reasonable computational cost.;In the second part of this study, diesel combustion modeling was performed using the above advanced spray model. The Shell ignition model, which uses a simplified reaction mechanism, was used to simulate the autoignition process of hydrocarbon fuels. The laminar-and-turbulent characteristic-time combustion model along with the Shell model was used to simulate the overall low and high temperature chemistry. The simulation results were compared with the experimental data with good agreement. The combination of combustion and spray models along with the dynamic mesh refinement was also validated using experimental data obtained from a heavy-duty diesel engine. In conclusion, a model, which is a combination of advanced spray model and combustion model with dynamic mesh refinement, was developed to simulate spray combustion in internal combustion engines. |
