Computational fluid dynamics modeling of combustion in heavy-duty diesel engines

Abstract

The design and optimization stages of combustion systems for modern heavy-duty diesel engines must be supported by reliable computational fluid dynamics tools for the definition of the chamber geometry and injection strategy. To be fully predictive in terms of in-cylinder thermodynamics and flame structure, the employed combustion models must account for complex chemistry and turbulence–kinetics interactions. Within this context, the authors have implemented into an open-source code a model based on the multiple representative interactive flamelets approach and applied it to diesel combustion simulations. New numerical techniques were integrated in the proposed multiple representative interactive flamelets model in order to speed up the central processing unit time in integrating chemistry and the β-probability density function of the chemical species to compute composition in the computational fluid dynamics domain. A parallel validation was performed both with constant-volume and heavy-duty diesel engine experiments, selecting similar operating conditions. In such way, both flame structure and heat release rate predictions are analyzed and the model capabilities with respect to its setup and mesh structure are assessed.