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It is well known that in automotive applications problems related to control and management are nowadays of paramount importance to improve engine performance and to reduce fuel consumption and pollutant emissions. In the design of control and diagnostics systems, the use of theoretical models proved to be very promising, also to reduce development time and costs, as widely documented in the open literature. From this point of view, the complexity of actual engines due both to the continuous enhancement of existing subsystems (e.g., turbochargers, exhaust gas recirculation systems, aftertreatment components, etc.) and to the introduction of specific devices (e.g., Variable Valve Actuation systems) give rise to challenging issues in modeling development and applications. The paper describes a theoretical model of an automotive engine built up starting from the original library developed in Simulink® by the authors for the simulation of last generation automotive engines.

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 modelbased 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).

Theoretical models are useful tools in the design of engine control systems, with applications that range from the design of engine layout, the definition of optimised management systems, to hardware-in-the-loop testing (HiL) and to model-based control strategies. To define theoretical models for control-oriented applications, an original library has been built up at the University of Parma for the simulation of the intake and exhaust systems of automotive turbocharged engines. Starting from this library, a Mean Value Model (MVM) of a Diesel engine, with variable-geometry turbocharger (VGT), EGR and throttle valve, has been developed for a small automotive application. In the paper the matching of the engine model with a detailed model of the exhaust system (developed by Magneti Marelli Powertrain) is presented.

In automotive applications problems related to control and diagnostics play an important role in the improvement of engine performance and in the reduction of fuel consumption and pollutant emissions. In this field theoretical models proved to be very useful, with applications that range from the definition of optimised management systems, to hardware-in-the-loop testing (HIL) and to model-based control strategies. However, control-oriented applications has to cope with the increasing complexity of actual automotive engines. In order to define “real-time” theoretical models for these applications, an original library has been developed by the authors for the simulation of complex systems [9,10,11], as intake and exhaust systems of automotive Diesel engines. “Quasi-Steady Flow” models and “Filling-and-Emptying” techniques were used for engine components and sub-systems.

Theoretical models are useful tools in the design of engine control systems, with applications that range from the definition of optimised management systems, to hardware-in-the-loop testing (HIL) and to model-based control strategies. To define theoretical models for control-oriented applications, an original library has been built up in Matlab®/Simulink® environment for the simulation of the intake and exhaust systems of automotive turbocharged engines. Starting from this library, a Mean Value Model (MVM) of a Diesel engine, with variable-geometry turbocharger (VGT), EGR and throttle valve, has been defined and fitted on a small automotive application. The model allowed to simulate in “real-time” engine behaviour: calculated and experimental data are reported and compared in the paper showing a good agreement both in steady and transient operating conditions.

The knowledge of unsteady flow characteristics of the different components usually present in the intake and exhaust systems of automotive i.c. engines can substantially improve the optimization of engine performance. Within this goal a broad investigation was developed in order to analyze the behavior of component of significant volume in unsteady flow conditions. Three elements of simplified geometry were considered in the study. Several measurements were performed on a dedicated test rig and experimental data were compared with the results provided by a simulation model, taking into account different calculation procedures to simulate the investigated components. The main conclusions of this study are presented and discussed in the paper.

The results of an extensive investigation developed on the wastegated radial flow turbine of a small automotive turbocharger are presented in this paper. Test rig measurements were performed to point out the influence of the by-pass opening on turbine performance. The analysis was extended both to steady and pulsating flow conditions, and controlled values of the main parameters of generated unsteady flow were obtained by a new dedicated turbine feeding line. A specific test method was followed in order to prevent inaccuracies in the definition of the waste-gate opening. The hypothesis assuming the turbine impeller and the waste-gate as two independent nozzles was studied in steady flow conditions. Turbine measured pulsating performance, which generally resulted higher than steady flow, was compared with the values supplied by analytical predicting models based on the quasi-steady flow assumption.