MODELLING OF COMMON RAIL FUEL INJECTION SYSTEM AND INFLUENCE OF FLUID PROPERTIES ON INJECTION PROCESS

This paper focuses on the modelling of a research type Heavy Duty Common Rail (CR) fuel injection system. More specifically it reports on the observed interaction between fuel properties and injection and on the capability to model this. For that reason a hydraulic model of the fuel injection system has been developed using the AMESim code (Imagine S.A., 2003). The reliability of the numerical results is tested through a comparison between numerical and experimental results when using regular diesel fuel. Basis for this detailed comparison are measurements of injected mass flow rate, needle lift and pressure oscillations in the injection duct for a single injection. Simulation results for regular diesel show good agreement with measured data for pressure oscillations in the injection duct, needle lift and injected fuel mass flow rate. A comparison of experimental and simulated results for Rapeseed oil Methyl Ester (RME) also shows good correspondence, which proves the capability of the model to capture the influence of different fuel properties.