Co-Simulation Modeling of High-Pressure Fuel System and Engine Performance System and Control System in Common Rail Diesel Engine

Abstract

The isolated sub-models may not yield adequate information to deal with system-level interactive issues in the diesel engine, especially when it comes to transient behavior. In this paper, at first the sub-models, which represent high-pressure fuel system and engine performance in common rail diesel engine, have been described with AMESim code, and fuel injection flow rate and cylinder pressure obtained by measurement are used to validate the sub-models. Then the validated sub-models, together with the sub-model of control system which is made with Matlab/Simulink, have been combined and a powerful complete co-simulation model is established. Intensive validation and application runs are underway. Several initial application runs indicate that the model is very effective in describing and analyzing the transient behavior connections among injectors, high-pressure pump, controller and engine parameters. An example of engine performance variability vs. the variability of injector control-valve-lift is simulated. It is found that the control-valve-lift variation has different impact for idle speed condition and maximum torque condition. Also, several initial runs indicate control strategy has great effect on the characteristic of fuel injection and engine performance, and the fluctuation of engine speed can be greatly reduced if control strategy is optimized.