Reliability of the current models of instantaneous pollutant emissions
JOUMARD ; PHILLIPPE ; VIDON
Type de document
COMMUNICATION AVEC ACTES INTERNATIONAL (ACTI)
Langue
anglais
Auteur
JOUMARD ; PHILLIPPE ; VIDON
Résumé / Abstract
Pollutant emissions and fuel consumption of passenger cars are usually assessed as a funtion of average speed. Nevertheless a number of attempts were made to take into account the driving pattern using emission vs instantaneous speed and acceleration models. Five quite similar models were developed in Europe. To which extent these instantaneous models are innovative as compared to conventional models? In a first step the various development the analysis was performed using the modem model, over 14 representative driving cycles under urban conditions. Average emissions as measured over these 14 cycles are compared to emissions calculated over same cycles using this model. Modelling errors range from -51% to +57%. This inaccuracy is quite similar for the other four European models. These models are barely more precise than average speed based models. In a second step, a number of alternatives liable to improve the reliability of instantaneous models are contemplated. But this does not improve significantly the model reliability. Limited measurements performed on a catalyst vehicle demonstrated that very high engine loads, yield emission values a thousand times higher. It is therefore of prime interest to study them in a comprehensive manner.
