High-Fidelity, Angle-Resolved Simulation Model for Predictions of Multi-Cylinder Engine Instantaneous Speed and Torque

A non-linear, angle-resolved, multi-cylinder SI engine computational model has been developed for predictions of instantaneous crankshaft speed and torque. The computation is firmly based on high-fidelity, comprehensive thermodynamic, steadystate, Two-Zone, Zero-Dimensional combustion model followed by a detailed analytical component model of engine friction and mechanical losses. Predictions of both engine cranking and steady-state operation conditions reveal strong dependence of variable engine moment of inertia and crankshaft instantaneous speed signal. The uncertainties and variation in the masses of the reciprocating slider mechanism components are further analysed in order to establish the impact on the instantaneous torque and speed profile. Self-tuning concept based on Levenberg-Marquardt Box-Constrained Optimisation algorithm has been introduced for model parameter identification