Crank-Angle Resolved Modeling of Fuel Injection and Mixing Controlled Combustion for Real-Time Application In Steady-State and Transient Operation

The present works presents a real-time capable engine model with physical based description of the fuel injection and the combustion process. The model uses a crank-angle resolved cylinder model and a filling and emptying approach for cylinder and gas-path interaction. A common rail injection system model is developed and implemented into the real-time engine framework. The injection model calculates injection quantity and injection rate profile from the input of the ECU signals target injection pressure and injection timing. The model accounts for pressure oscillations in the injection system. A phenomenological combustion model for Diesel engines is implemented, which is based on the mixing controlled combustion modeling approach. The combustion model calculates the rate of heat release from the injection rate given by the injection model. The injection and combustion model are validated in detail against steady-state measurement data for two different passenger car sized engines. A wide range of operating conditions is considered, covering full load and part load operating points with single and multiple injections. Based on the steady-state calibration, a transient engine model is set up, which uses the physical based injection and combustion sub-models. The engine model is used together with a driveline model in a system engineering framework and drive-cycle simulations are performed. The combined model is assessed in terms of calculation time. Not only in average the model is significantly faster than real-time, but also the peak value has sufficient safety margin to the real-time limit. Therewith the model is ready to support hardware in the loop simulation tasks.