Modelling of turbocharged diesel engines in transient operation. Part 1: Insight into the relevant physical phenomena

Abstract

A new calculation model, able to predict the engine performance during an engine transient, has been developed, based on an existing wave action code. Previously to the model development, the turbocharged diesel engine's transient phenomena (turbocharger lag, thermal transient and energy transport delay) were deeply analysed on the basis of experimental information. The study has been focused on the load transient, i.e. torque increase from idle, at constant engine speed of a high speed direct injection (DI) turbocharged engine. Experimental load transient tests have been performed, with the aim of obtaining a combustion database during engine transient operation, to input into a combustion simulation submodel. The applied methodology allows the characterization of the transient combustion process in any DI turbocharged engine.