Influence and potential of flexible injection rate shaping for medium and heavy duty diesel engine combustion processes

Abstract

Modern fuel injection systems for medium and heavy duty diesel engines combine the potential of very high injection pressures and flexible injection rate shaping. Against this background, the Commercial Vehicle Division of DaimlerChrysler AG, in close collaboration with DaimlerChrysler Research, performed principle tests to assess the influence of a flexible injection process, focusing on the effects of injection rate shaping. Besides pressure indexing, optical diagnostic methods and simulation techniques provided valuable insights in this study. Within this project, four different injection systems with different potentials of flexibility were investigated. New insights, such as the influence of needle opening and closing behaviour on nitric oxide emissions and the influence of injection rate shaping on soot emissions have been elaborated.