Heavy Duty Diesel Engine and EAS Modelling and Validation for a Hardware-in-the-Loop Simulation System

Towards a Powerful Hardware-in-the-Loop System for Virtual Calibration of an Off-Road Diesel Engine

“…The classic species balance equations [38] are considered to reproduce the influence of the gas composition on the fluid physical properties for the whole ICE operating map such as different exhaust gas recirculation and different exhaust gas temperatures: this method is necessary to model the states in the storage elements and the flow through the transfer elements. As described in [39], the classic species approach is useful to reduce the computational cost. Thus, conservation equations for combustion products and fuel vapor are solved.…”

“…This path structure consists of two parts: a convective heat exchange between the solid wall and the gas within the volume, and a convective heat transfer between the environment and the solid wall. The Heat Transfer Coefficient (HTC) between the environment and the solid wall was estimated according to literature values and in particular to [39], whereas the convective heat transfer ( . Q) between the solid wall and the gas in the plenum, is calculated Energies 2022, 15, 646 9 of 28 from the convective law, assuming a constant wall temperature (T w ) and a constant gas temperature (T gas ), according to Equation ( 9…”

“…Another important aspect of the engine model is the prediction of the coolant temperature behavior during the warm-up phase because a lot of ECU strategies are based on that temperature. The transient evolution of the coolant temperature is evaluated taking into consideration that in the coolant circuit, the temperature derivative is proportional to the heat flux divided by systems thermal inertia (Figure 6) [39]. When the simulated temperature reaches the target thermostat temperature, a saturator signal is activated.…”

“…On account of the above shortcomings, polynomial models were chosen instead, and they were generated using an optimization tool. The structure of each user-defined emission models consists of polynomials with terms up to fifth order and includes cross interactions up to fourth order as described in [39]. The output of these kinds of models is a function of the engine speed, the oxygen content in the cylinder, the rail pressure, the injections timing, the air to fuel Therefore, a specific design of experiments (DoE) program was delineated to create a user-defined emission models based on empirical correlations.…”