Real-time single zone model for simulation of a diesel engine in Simulink environment

Diesel-fuelled compression ignition engines find wide range of applications from light duty to heavy duty engines, also exhibiting higher fuel conversion efficiencies than that of petrol-fuelled spark-ignition engines. However, diesel engines suffer from high NO and soot emissions with trade off, making the development of high efficiency and less polluting engines a necessity. Hence understanding the dependence of the performance parameters like in-cylinder pressures, temperatures and efficiencies on different operating parameters becomes essential. Researchers are concentrating on computational studies which would simultaneously reduce the experimental setup cost and time. In the present study, a diesel engine model has been developed in Simulink environment taking into consideration mass flows through valves, double-wiebe interlaced function, heat transfer and variable specific heats. The model is developed using basic blocks available in the Simulink library. The developed model overall computational time took less than a second for completion of a single working cycle. Validation of the model is done with an acceptable match between the numerical results and the experimental data under different load conditions. The paper further presents diesel engine simulation under different operating parameters which include fuel injection timings, EGR fractions, inlet pressures and loads. The model aims for real-time operation for various speeds and achieves it under 2000 rev/min. Furthermore, the minimum computational time step size is discussed for numerical stability of the simulation results.