Shaping the injection rate in Diesel engines influences combustion and emissions. Fluid-dynamic steady-state characteristics and transient response of the control valve of high-pressure, electronically controlled, injection systems are important factors for the control of the shape, duration and timing of the injection, especially during pilot injections.
Computed results, obtained using a model to predict the cavitation behavior of the control valve of a high-pressure fuel injection system for Diesel engine, are presented. The numerical investigation has been made using different cavitation models, involving the hypothesis of a barotropic cavitation, or fluid dynamic model with non-equilibrium cavitation modeling.
As a result, the computed mass flow values were compared with the experimental data. Calculations have been performed to investigate the influence of the transient development of the cavitation. The calculations showed that the control valve operate in transient conditions, especially during pilot injections.