COMPUTATIONAL SIMULATION OF THERMAL AND CHEMICAL BEHAVIOR DURING THE COMBUSTION PROCESS IN DIESEL ENGINE

Abstract

The purpose of this paper is the modeling and simulation of one of the most challenging processes in internal combustion engines, combustion. The first objective was to analyze and study the thermodynamic and fluid dynamic behavior within the combustion chamber. Since detailed chemistry requires a great deal of time and computer resources, our aim is to implement a simple and accurate model to simulate and predict the combustion process. To this end, numerical methods have been developed through the techniques of Computational Fluid Dynamics (CFD). In addition to the basic equations of mass, momentum and energy, the mathematical model developed included equations of state, a turbulence model and a model of the spraying mechanism. For chemical behavior and pollutant formation, we developed a new chemical model based on the Intrinsic Low-dimensional Manifold (ILDM) and homogeneous reaction methods that automatically reduces detailed chemistry. Kiva CFD software is used as the solver for all models developed. The analysis of the results shows the importance of swirling and turbulent motions for spray penetration, ignition, and flame propagation. The results for NO x and soot formation, as the main pollutant emissions from the diesel engine, showed different behavior for their formation conditions. These results also show that there is good agreement within the mechanism used to make their predictions. The credibility of the built model is increased by comparing the pressure results with the experimental ones. Keywords: Combustion, Diesel Engine, Modeling, Computational Fluid Dynamics, Pollutant Formation DOI： https://doi.org/10.35741/issn.0258-2724.58.2.20