Today restrictions on pollutant emissions require the use of catalyst-based after-treatment systems as a standard both in SI and in Diesel engines. The application of monolith cores with a honeycomb structure is an established practice: however, to overcome drawbacks such as weak mass transfer from the bulk flow to the catalytic walls as well as poor flow homogenization, the use of ceramic foams has been recently investigated as an alternative showing better conversion efficiencies (even accepting higher flow through losses). The scope of this paper is to analyse the effects of foam substrates characteristics on engine performance. To this purpose a 0D “crank-angle” real-time mathematical model of an I.C. Engine developed by the authors has been enhanced improving the heat exchange model of the exhaust manifold to take account of thermal transients and adding an original 0D model of the catalytic converter to describe mass flows and thermal processes. The model has been used to simulate a 1.6l tuIntroduction
In the last decades the constant need to reduce pollutant emissions from Internal Combustion Engines (ICEs) led OEMs both to enhance existing subsystems (e.g., fuel injection, valve actuation systems, etc.) and to introduce innovative solutions (with particular reference to after-treatment devices). As a matter of fact, in order to allow these technologies to be really effective, a proper and concurrent design of plant layout, control systems and management strategies is needed.
The complexity of systems and the large number of control variables require a deep understanding of processes that determine the behavior of the controlled powertrain as a system as a whole. The design of system architecture and of its control devices definitely need a solid theoretical support from physical models to outline system overall behavior, which is mostly non-linear and therefore difficult to predict. Mathematical models are powerful tools to estimate the influence of system layout and control strategies on the final result thus shortening the way from design specifications to on-road testing (Guzzella and Onder, 2010).
The application of fast mathematical models in the design of powertrains and related management systems is well-known for more than a decade and several examples can be found in the literature (Gambarotta and Lucchetti, 2011). A comprehensive scenario is outlined in (Guzzella and Onder, 2010). Typically Filling-and-Emptying (F&E) and Quasi-Steady Flow (QSF) approaches are used to build up 0D, lumped parameter