Powertrain Simulation Tools and Application to the Development of a SI Engine Concept Car

The powertrain simulation tools are nowadays an efficient support to optimize cost and duration of the whole engine technological developments. They can deliver optimized simulator versions for various targets such as system understanding, design investigation, non-measurable value access or virtual bench use for control and calibration. Under the condition of an accurate modelling and simulation know-how to take into account the simulator using constraints, the simulation can become an undisputable support for powertrain design as the test bed already is.

The goal of this paper is to present the large range of the powertrain simulation capabilities for the specific application of a downsized turbocharged GDI engine with twin VVT embedded in a concept car. The modelling framework is first presented and different items are laid-out. A first part is dedicated to the engine air path and in particular to the modelling of gas exchange phenomena such as back-flow. A second point concerns the development of combustion and pollutant models compatible with a high level of modelling accuracy or high CPU time constraints. For this purpose neural network based models are used in combination with phenomenological models. A last part is devoted to the powertrain modelling and to the presentation of some results obtained on a NEDC cycle.

This paper finally demonstrates that, combining all these models and using them for the development of a SI engine concept car, the powertrain simulation can propose a very large range of dedicated simulators in the same environment and provides answers for the whole expectations of the complete engine design process.