The role of computer aided engineering in the design optimization of exhaust after-treatment systems

Abstract

The goals of employing computer aided engineering (CAE) tools have always been the improvement of product quality and the simultaneous reduction of the related time-to-market and development costs. The latter may be achieved when the optimization procedure is carried out without the need to construct and test numerous prototypes. CAE tools and methodologies, apart from the design phase, can also be employed for dedicated prediction and analysis purposes, with the intention to fully exploit the capabilities of the catalytic exhaust system. A set of fundamental CAE tools and the accompanying (CAE) methodology, aiming to assist the design optimization of catalytic exhaust systems for spark-ignition-engined vehicles, are presented. The set comprises the following individual cooperating modules: a transient exhaust system heat transfer code, a transient three-way catalytic converter (3W-CC) computer code with an accompanying kinetics tuning procedure, a 3W-CC database and an ageing assessment methodology. The CAE methodology may be exploited in the directions of exhaust system design and optimization, addressing the catalytic exhaust system as an entity that consists of interrelated components. In that context, specific examples of real practice are demonstrated. This methodology is already being extensively used by the authors in research and development of automotive exhaust after-treatment systems, with promising results.