Hardware-in-the-Loop (HiL) approaches are becoming popular when the engine system is represented as a real-time capable model to allow development of the controller hardware and software without the need for the real engine system. A number of semi-physical, zero-dimensional combustion modelling techniques are enhanced and combined into a complete model, these include- ignition delay, pre-mixed and diffusion combustion and wall impingement. A fuel injection model was used to provide fuel injection rate from solenoid energizing signals.
The model was parameterized using a small set of experimental data and validated against a complete data set covering the full engine speed and torque range. The model was shown to characterize Rate of Heat Release (RoHR) well. Critically the wall impingement model improved R2 value for maximum RoHR from 0.89 to 0.96. This reflected in the model’s ability to match both pilot and main combustion phasing, and peak heat release rates derived from measured data. The model predicted indicated mean effective pressure and maximum pressure with R2 values of 0.99 across the engine map. The results demonstrate the predictive ability of the model, with only a small set of empirical data for training - this is a key advantage over conventional methods. The fuel injection model yielded good results for predicted injection quantity (R2=0.99), and enables the use of the RoHR model without the need for measured rate of injection.