Methodology for characterisation and simulation of turbocharged diesel engines combustion during transient operation. Part 2: Phenomenological combustion simulation

Once applied the procedure to carry out the obtaining of the rate of heat release (RoHR) of every cycle during engine transient operation from the experimental test, the following step consists in parametrizing it by means of Wiebe's functions. In order to perform this task, a procedure based on statistical fitting subjected to phenomenological criteria is developed and explained in depth. The suggested criteria link the parameters defining the Wiebe's functions to the general concepts of Diesel combustion and have been shown applicable to both steady and transient engine operation. Their application improves the statistical fitting of the RoHRs in terms of reduction of uncertainties in the adjustment and computational effort requirements.