A thermodynamic Mean Value Model of the intake and exhaust system of a turbocharged engine for HiL/SiL applications.

Regarding automotive applications, Internal Combustion Engines (ICE) have become very complex plants to comply with present and future requirements in reduction of fuel consumption, pollutant emissions and performance improvement. As a consequence, the development of engine control and diagnostic system is a key aspect in the powertrain design. Mathematical models are useful tools in this direction, with applications that range from the definition of optimised management systems, to Hardware- and Software-in-the-Loop testing (HiL and SiL) and to model- based control strategies. To this extent an original library has been developed by the authors for the simulation of last generation automotive engines. Library blocks were used to assembly a sub-model of the typical intake and exhaust system of a turbocharged engine (with VGT, intercooler, EGR circuit with cooler and throttle). The simulation procedure, developed in Simulink® and based on a physical modelling of the gas path, was then integrated in a HiL test bench from dSpace Gmbh at Magneti Marelli Powertrain facilities. After calibration and validation –with reference to a small Common Rail Diesel engine- it was widely used in SiL/HiL testing. In the paper the model is presented and several results are reported.