Analysis of energy transfer in automotive engines

The European situation regarding CO ₂ emissions (representative of consumption) by passenger cars is conditioned by the manufacturers' commitment under ACEA (Association of European Automobile Manufacturers) to limit these emissions to 120 g/km by 2012.

Analysis of the excess fuel consumption of internal combustion engines corroborates the predominance of thermal parameters associated with short-distance journeys of less than 3 km (47% of current vehicle use), leading to excess fuel consumption of 80% compared with a journey of 10 to 50 km.

Anti-pollution legislation is another factor. Thanks to improvements in fuel injection technologies, a better understanding of combustion phenomena and the advent of after-treatment systems, pollutant emissions have been progressively reduced, and today represent only one tenth of the level in the 1980s. Here again, the formation and treatment of pollutant emissions are essentially associated with complex thermochemical processes highly dependent on thermal parameters (the trend is towards the widespread use of catalysis elements requiring operating temperatures in excess of 300 ˚C).

The energy aspect of heat transfer within motors is therefore becoming an increasingly important factor in the design of these machines.

This study consists of two articles:

• [BM 2900] Analysis of energy transfer in automotive engines ;

• Modeling heat transfer in automotive engines.