Practical delay modeling of externally recirculated burned gas fraction for Spark-Ignited engines

Abstract : In this chapter, the authors provide an overview and study of the low- pressure burned gas recirculation in spark-ignited engines for automotive power- train. It is shown, at the light of supportive experimental results, that a linear delay system permits to capture the dominant effects of the system dynamics. The mod- eled transport delay is defined by implicit equations stemming from first principles and can be calculated online. This model is shown to be sufficiently accurate to replace a sensor that would be difficult and costly to implement on commercial engines.