The experimental characterization o

The experimental characterization of the DDI injection system was carried out in terms of both hydraulic behavior and of sprays evolution. For the analysis of the hydraulic operation, the mean injected volumes and the injection rate produced by the DDI system at various rail pressure levels and solenoid energizing times ware investigated. For the spray evolution characterization, the global shape of the five jets emerging from the nozzle was analyzed by means of imaging defining the main global spray parameters. Further the sizing and velocimetry of the spray were analyzed by a Phase Doppler Anemometry system. All the obtained experimental data were used both for a direct evaluation of the system operation capabilities and as boundary conditions and final check for the accuracy of the proposed CFD methodology.