Diesel engine combustion modeling for hardware in the loop applications: Effects of ignition delay time model

This paper deals with the development of a phenomenological combustion single zone model of Diesel engine. The aim of this work is to build a model suitable for HiL (Hardware in the Loop), and thus to be able to run in Real-Time applications. The combustion sub-model estimates the heat release rate by the sum of two algebraic expressions related to premixed and diffusive burning process. The Wiebe correlation has been used to model each algebraic expression of the combustion sub-model. The ignition delay time required by the combustion sub-model has been modeled through an Arrhenius correlation and an algebraic simple correlation. An extensive identification analysis has been performed to express their dependence with respect to engine operating conditions. The global model has been built with the constraints of computational CPU load that characterize the real time simulations. The accuracy of the model in predicting the in cylinder pressure has been tested over a large set of measurements at different engine operating conditions. The comparison of in-cylinder pressure profiles with experimental traces has shown that the Arrhenius expression is less accurate than the simple correlation. However, these two approaches may be used in real time modeling.