Numerical and Experimental Assessment of a Solenoid Common-Rail Injector Operation with Advanced Injection Strategies

The selection and tuning of the Fuel Injection System (FIS) are among the most critical tasks for the automotive diesel engine design engineers. In fact, the injection strongly affects the combustion phenomena through which controlling a wide range of related issues such as pollutant emissions, combustion noise and fuel efficiency becomes feasible. In the scope of the engine design optimization, the simulation is an efficient tool in order to both predict the key performance parameters of the FIS, and to reduce the amount of experiments needed to reach the final product configuration. In this work a complete characterization of a solenoid ballistic injector for a Light-Duty Common Rail system was therefore implemented in a commercially available one-dimensional computational software called GT-SUITE. The main phenomena governing the injector operation were simulated by means of three sub-models (electro-magnetic, hydraulic and mechanical). The model was validated using experimental data obtained by a Zeuch's method injection analyzer. To this end, the experimental injection rate profiles and injected volumes along with rail pressure profiles were acquired in several multi-event injector operation strategies pertaining to different engine operating conditions, typical of the NEDC operation. The use of different Energizing Time (ET) and Dwell Time (DT) values allowed the evaluation of the injector potential in applying advanced actuation strategies and the assessment of the model capability to simulate the injection system operation in challenging operating conditions such as close injection events.