The Influence of Transient Conditions on the Operation of an SI Engine, Especially with Respect to Exhaust Emissions

Engines of passenger cars operate almost exclusively under transient conditions. However, all influencing parameters are tailored to steady-state operation. An experimental investigation was made to determine if the correlations between emissions and engine operation on the one hand and on the other hand, the influencing parameters which are well known for steady-state conditions are valid also for transient operation.

The basic concept of the investigations and the experimental setup are described briefly. The results show clearly the differences between steady-state and transient operation, which are mainly caused by temperature effects.